363 .7009773 0360 The con.5 a NS) CChangi Illinois Environment: Critical Trends Volume 3: Ecological Pa , é: be // 1° HG m4, HI nt y7E yy Ap SAOOR ee , Ge me Be ae. ref A / AN Illinois Department of Energy and Natural Resources June 1994 ILENR/RE-EA-94/05(3) Matural History Survey Library ILENR/RE-EA-94/05(3) The Changing Illinois Environment: Critical Trends Technical Report of the Critical Trends Assessment Project Volume 3: Ecological Resources Illinois Department of Energy and Natural Resources Illinois Natural History Survey Division 607 East Peabody Drive Champaign, Illinois 61820-6917 June 1994 Jim Edgar, Governor State of Illinois John S. Moore, Director Illinois Department of Energy and Natural Resources 325 West Adams Street, Room 300 Springfield, Illinois 62704-1892 Printed by Authority of the State of Illinois Printed on Recycled and Recyclable Paper Illinois Department of Energy and Natural Resources 325 West Adams Street, Room 300 Springfield, Illinois 62704-1892 Citation: Illinois Department of Energy and Natural Resources, 1994. The Changing Illinois Environ- ment: Critical Trends. Summary Report and Volumes 1 - 7 Technical Report. Illinois Department of Energy and Natural Resources, Springfield, IL, ILENR/RE-EA-94/05. Volume 1: Air Resources Volume 2: Water Resources Volume 3: Ecological Resources Volume 4: Earth Resources Volume 5: Waste Generation and Management Volume 6: Sources of Environmental Stress Volume 7: Bibliography AUTHORS AND CONTRIBUTORS Prairies Authors Ken R. Robertson, Mark W. Schwartz Contributors V.Lyle Trumbull, Ann Kurtz, Ron Panzer Forests Authors Louis R. Iverson, Mark W. Schwartz Contributors James E. Appleby, Jeffrey D. Brawn, Loy R. Phillippe, Richard E. Warner Agricultural Lands Authors Richard E. Warner, David W. Onstad Contributor Charles G. Helm Wetlands Authors Stephen P. Havera, Liane B. Suloway Contributors Sharon Baum, Joyce Hofmann, Dennis Keene, Marilyn Morris, Alicia Nugteren, Tony Shaffer, Scott Simon, John Taft, Patti Malmborg Lakes and Impoundments Authors Peter B. Bayley, J. Ellen Marsden, Douglas J. Austen Contributor Dan Gavrilovic Flowing Waters Coordinators Steven L. Kohler, Lewis L. Osborne Authors Steven L. Kohler, Mark F. Kubacki, Richard E. Sparks, Thomas V. Lerczak, Daniel Soluk, Peter B. Bayley, Kevin S. Cummings, Mitchell A. Harris, Lawrence M. Page, Steve G. Gough, Charles H. Theiling Contributors Diane L. Szafoni, Dan Gavrilovic, Deborah Corti, Brian J. Swisher, Kyle Piller, Katherine J. Hunter, Glendy C. Vanderah, Carolyn Nixon, Deanne L. Krumwiede Resource Analysis Authors Robert A. Herendeen, Kenneth P. Pabich This volume was written and produced by staff of the Illinois Natural History Survey, Champaign. Technical editor: John P. Ballenot Wyaot, Caper of Baengy pad Nelternt Be Ween Alle Bene, Mikes BA Spring Geld, Hinols’ GUAM-TRER a eet ete oge voy A evel Jalee foimgel diaz A Noda aynenemis a Veotieties G) Gaus nes of Envimameyta Sirens ais seated ransiier uw sctlioe sit es SF vows ronald terre ebb, - ponahtes Andel imate ese gan sf ont st cn pares th — gah crhig A ne ABOUT CTAP ABOUT THE CRITICAL TRENDS ASSESSMENT PROJECT The Critical Trends Assessment Project (CTAP) is an on-going process established to describe changes in ecological conditions in Illinois. The initial two-year effort involved staff of the Illinois Department of Energy and Natural Resources (ENR), including the Office of Research and Planning, the Geological, Natural History and Water surveys and the Hazardous Waste Research and Information Center. They worked with the assistance of the Illinois Environ- mental Protection Agency and the Illinois depart- ments of Agriculture, Conservation, Mines and Minerals, Nuclear Safety, Public Health, and Trans- portation (Division of Water Resources), among other agencies. CTAP investigators adopted a “source-receptor” model as the basis for analysis. Sources were defined as human activities that affect environmental and ecological conditions and were split into categories as follows: manufacturing, transportation, urban dynamics, resource extraction, electricity generation and transmission, and waste systems. Receptors in- cluded forests, agro-ecosystems, streams and rivers, lakes, prairies and savannas, wetlands, and human populations. The results are contained in a seven-volume technical report, The Changing Illinois Environment: Critical Trends, consisting of Volume 1: Air Resources, Volume 2: Water Resources, Volume 3: Ecological Resources, Volume 4: Earth Resources, Volume 5: Waste Generation and Management, Volume 6: Sources of Environmental Stress, and Volume 7: Bibliography. Volumes 1-6 are synopsized in a summary report. The next step in the CTAP process is to develop, test, and implement tools to systematically monitor changes in ecological and environmental conditions in Illinois. Given real-world constraints on budgets and human resources, this has to be done in a practi- cal and cost-effective way, using new technologies for monitoring, data collection and assessments. As part of this effort, CTAP participants have begun to use advanced geographic information systems (GIS) and satellite imagery to map changes in IIli- nois’ ecosystems and to develop ecological indicators (similar in concept to economic indicators) that can be evaluated for their use in long-term monitoring. The intent is to recruit, train, and organize networks of people — high school science classes, citizen vol- unteer groups — to supplement scientific data collec- tion to help gauge trends in ecological conditions. Many of the databases developed during the project are available to the public as either spreadsheet files or ARC-INFO files. Individuals who wish to obtain additional information or participate in CTAP programs may call 217/785-0138, TDD customers may call 217/785-0211, or persons may write: Critical Trends Assessment Project Office of Research and Planning Illinois Department of Energy and Natural Resources 325 West Adams Street, Room 300 Springfield, IL 62704-1892 Copies of the summary report and volumes 1-7 of the technical report are available from the ENR Clearinghouse at 1/800/252-8955. TDD customers call 1/800/526-0844, the Illinois Relay Center. CTAP information and forum discussions can also be accessed electronically at 1/800/528-5486. FOREWORD FOREWORD "If we could first know where we are and whither we are tending, we could better judge what we do and how to do it..." Abraham Lincoln Imagine that we knew nothing about the size, direction, and composition of our economy. We would each know a little, i.e., what was happening to us directly, but none of us would know much about the broader trends in the economy — the level or rate of housing starts, interest rates, retail sales, trade deficits, or unemployment rates. We might react to things that happened to us directly, or react to events that we had heard about — events that may or may not have actually occurred. Fortunately, the information base on economic trends is extensive, is updated regularly, and is easily accessible. Designed to describe the condition of the economy and how it is changing, the information base provides the foundation for both economic policy and personal finance decisions. Typical economic decisions are all framed by empirical knowledge about what is happening in the general economy. Without it, we would have no rational way of timing these decisions and no way of judging whether they were correct relative to trends in the general economy. Unfortunately, this is not the case with regard to changes in environmental conditions. Environmental data has generally been collected for regulatory and management purposes, using information systems designed to answer very site-, pollutant-, or species- specific questions. This effort has been essential in achieving the many pollution control successes of the last generation. However, it does not provide a systematic, empirical database similar to the eco- nomic database which describes trends in the general environment and provides a foundation for both environmental policy and, perhaps more importantly, personal decisions. The Critical Trends Assessment Project (CTAP) is designed to begin developing such a database. As a first step, CTAP investigators inventoried existing data to determine what is known and not known about historical ecological conditions and to identify meaningful trends. Three general conclu- sions can be drawn from CTAP’s initial investiga- tions: Conclusion No. 1: The emission and discharge of regulated pollutants over the past 20 years has declined, in some cases dramatically. Among the findings: * Between 1973 and 1989, air emissions of particulate matter from manufacturing have dropped 87%, those of sulfur oxides 67%, nitrogen oxides 69%, hydrocarbons 45%, and carbon monoxide 59%. e Emissions from cars and light trucks of both carbon monoxide and volatile organic com- pounds were down 47% in 1991 from 1973 levels. * Lead concentrations were down substantially in all areas of the state over the 1978-1990 period, reflecting the phase-out of leaded gasoline. ¢ From 1987 to 1992, major municipal sewage treatment facilities showed reductions in loading of biological/carbonaceous oxygen demand, ammonia, total suspended solids and chlorine residuals that ranged from 25 to 72%. e Emissions into streams of chromium, copper, cyanide, and phenols from major non-municipal manufacturing and utility facilities (most of them industrial) also showed declines over the years 1987-1992 ranging from 37% to 53%. Conclusion No. 2: Existing data suggest that the condition of natural ecosystems in Illinois is rapidly declining as a result of fragmentation and continual stress. Among the findings: e Forest fragmentation has reduced the ability of Illinois forests to maintain biological integrity. In one Illinois forest, neotropical migrant birds that once accounted for more than 75% of breeding birds now make up less than half those numbers. FOREWORD ¢ In the past century, one in seven native fish species in Lake Michigan was either extirpated or suffered severe population crashes and exotics have assumed the roles of major predators and major forage species. * Four of five of the state’s prairie remnants are smaller than ten acres and one in three is smaller than one acre — too small to function as self- sustaining ecosystems. ¢ Long-term records of mussel populations for four rivers in east central Illinois reveal large reduc- tions in numbers of all species over the last 40 years, apparently as suitable habitat was lost to siltation and other changes. e Exotic species invasions of Illinois forests are increasing in severity and scope. Conclusion No. 3: Data designed to monitor compli- ance with environmental regulations or the status of individual species are not sufficient to assess ecosys- tem health statewide. Among the findings: ¢ Researchers must describe the spatial contours of air pollutant concentrations statewide using a limited number of sampling sites concentrated in Chicago and the East St. Louis metro area. * Much more research is needed on the ecology of large rivers, in particular the effects of human manipulation. * The length of Illinois’ longest stream gaging records is generally not sufficient to identify fluctuations that recur less frequently than every few decades. ¢ The Sediment Benchmark Network was set up in 1981 with some 120 instream sediment data stations; by 1990 the network had shrunk to 40 stations, the majority of which have data for only one to three years. CTAP is designed to begin to help address the complex problems Illinois faces in making environ- mental policy on a sound ecosystem basis. The next edition of the Critical Trends Assessment Project, two years hence, should have more answers about trends in Illinois’ environmental and ecological conditions to help determine an effective and economical environmental policy for Illinois. VOLUME SUMMARY The Illinois Natural History Survey’s contribution to the Critical Trends Assessment Project is in seven sections, here bound in one volume. The first six sections cover six ecosystem types: prairies, forests, agricultural lands, wetlands, lakes and impoundments, and flowing waters. The seventh covers resource issues. For each section there is a summary of one or two pages. To summarize the summaries: Although we lack an overall metric of ecosystem health, Illinois ecosystems are greatly affected by human activity, and that effect in general seems to be increasing. This is in spite of many specific improvements and an overall reduction in pollution sources. Often the largest impact is land use, the weight of many pressures on few acres. Prairies. The Illinois tallgrass prairie, which originally covered 60% of the state, is 99.99% gone. Forests. Originally diminished by development, forests are coming back; forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmen- tation and by exotic species. Agricultural Lands. Eighty percent of the state is farmland. Intensive monoculture has impoverished ecosystems and affected streams. Some improvement is now occurring; erosion rates are diminishing, for example. Wetlands. Illinois was originally 25% wetlands. It is now 3% wetlands, with only 0.016% classified as approaching pristine. Wetlands are also repositories of endangered and threatened species. Lakes and Impoundments. Except for Lake Michigan and a few lakes in northern Illinois, essentially all lakes in Illinois are artificial. Lake Michigan fish species have been significantly affected by introduced exotics and fishing pressure. Impoundments are seriously affected by stream sedimentation and eutrophication, both products of activities in the surrounding watershed. Flowing Waters. Water quality has historically deterio- rated, leading to the extirpation and threatened extirpa- tion of many species (19-55%) of fish, amphibians and reptiles, mussels, and crayfish. Recently there has been environmental improvement in large rivers (Mississippi and Illinois) because of reduced point-source pollution (e.g., sewage). However, there are persistent and serious sedimentation and chemical problems, which again reflect activities in the watersheds. Resource Analysis. A broad indicator of overall environmental impact is the ratio of fossil fuel con- sumption (including consumption by nuclear power plants) to solar radiation. In Illinois this averages 0.06, which is 600 times the world average, seven times China’s average, and about half of Germany’s average. In Chicago the ratio is approximately one. Illinois has much coal, but the state could not be self-sufficient for more than 10 months in its use of oil or for more than a few weeks in its use of natural gas. Soil erosion is diminishing, and even at today’s rate of erosion topsoil will last several hundred years on average. There is wide variation in this lifetime from county to county. A aes VV VN a Net Heed, Sur Vel. 3 Cen -% CONTENTS NS ei as ee Na rs gids Aa Ss Shan oo) s= vos Deena hat canal egies tu-enieek eeu be asta as ae Ue are t ieray Uc ccean Legs a 0 Aaa wna son enn nena SuaaE RM de dda Anat dah ce cah sat pedal wears DeTtpeel 33 ei iL BE TCR Ea hc nn or ie cee ae Rm EE ety See a 67 0 EDT ie east cetesiace heen Lk a I i ek Ro PA eee Be oie Br oie pe Poe ee thd: Same ber tS A 87 RENAE NEY INC TME AEDS Si cosa crc dec asin scs RH sf A? : ; Alt cies Ua VOL UAE SUMMARY: 2020). MN ' ey ’ Pa - , J 4 ethane “7 HP ee? \ reowy: Serves’ PORE ORANG fern’ reseed Parone nny tha'€’viticn! Trends Agape Project ts Ueseyen/* ° tafe tas here at¢tipes, urs. Sn |i pie votuine. ‘The fiesta. -!" Mit We Salonen: ie ti Seer) oy 2 ee ty EDAD CO RMDEI: Rip ee waren: + yoann nt eater a nt, © ethan, lakes cng Latace oc, . una thebhng, Terad - til Wowrvat Ww ators. The geverth carvers es. ; ae Re ] ve ti, CO Lae che ci 20.44 w Marry sf und Mee ela iek _ ah gion tt ye page ) ; P lowlty Waser. Waar Wye Nabe Ay. gat nyt Cale th w WCIE ee ay nis ination, ane sept wile oi OCONYseID heat, Minety eons yates ; cof wueny kf Sm ad ax see att AsTerte 4 by nena activaly! ancl oy chit: rei wo api nat teen, Tig ioe ang TI MI cane cnnler 8 ach vaanettles CMPD re petitR Wyld Af <5 ‘st nl Teel Lyculien i leq uilewre naareea | Ofiein tha torpest linpecs is land . ihe athyht ata ay per rete ca (hey ROO pate ’ ai bdé ern reend ty he pemed ean snmret mre nee esos bbe c006 c04 Te pee hare ® ha Vener eep a = gu: ae a patie: Te Tuy Laltgpets prairie, alin dayinitty he t aileiedll OOS cif ted hate ta FF. 99%, BORK ee ye feats es os beayebv ar bee ter era Aa obec wrve a bagh yt heers enede bac ybaden ty wate tose. “evar Poavge Onipiwily dial Adxtieed Dry deve sapere, ee (hace * jee reals Oh: Forel biomians ty gocmmaeltaiyg. , varcarg) tn ola NK iS Oe NOD Wlcs far mary pater specie. which 8 04RD thm ae eg co bd Suan: wih ypceonsnil viniating (iio, wawores, hie tei coo Ss or ’ eve : weds ool, Bet Cr ‘warto cond, ee, fg : * 98 Fae hehe dhe sine mnenes Foeka peng e } talon! Land, £. any vides ol tas sete few evn a ciara cant = RO Wwedes . ae 72, * diapahdl, Dooondive monposlture hax impo rertiied firniniohieg, ®: ad ‘ead sedsy ters and stectéf Meendts. Some Haproverncet fe will luyt eeweral Mende Liter OCC: addline takes weed mimshing tov \ wwiste E srasatin Wo aii eyetinis ; c* : je oitee. My i i ' ‘> af Paks ; ’ ¢ | Ss , é ‘ tigi h ete: Thingy was Udpiod ty 24'e.s woelartie Ma i ye q:.J5 Fee) ae nl Sew 1% coins! Mth weky D.0N6% clateilied ag!" wn 44 ie ee ay Te aprecichi hg crtatige, Wailan ate ale pepoatories of ae ll a Lg 1 es eto tm en@angeredd ntl iNpentohed) pte ’ Pee een Mi - PRAIRIES SUMMARY Grasslands are biological communities in which the landscape is dominated by herbaceous vegetation, especially grasses; they contain few trees or shrubs. Approximately 32 to 40% of the world’s land surface is, or was, covered by grasslands. In North America, grasslands are the largest vegetation type, covering approximately 15% of the land area. The most abun- dant grasslands in North America are prairies. Illinois lies within an eastward extension of the tallgrass prairie called the prairie peninsula. Before people of European descent settled in the region, this prairie extension was bounded on the north, east, and south by deciduous forests. At one time, Illinois, the Prairie State, was about 60% prairie, found mainly in the northern two-thirds of the state. Forests were generally restricted to stream banks and the northwest- ern and southern portions of Illinois. In an astonishingly short period, roughly between 1840 and 1900, a vast amount of tallgrass prairie was destroyed. The Illinois Natural Areas Inventory has concluded that only oo of 1% of the original prairie remains, with only 2,352 acres of high-quality prairie remaining. High-quality (grade A and B) prairie remnants tend to be found in very small patches. Of the 253 prairie sites identified by the Illinois Natural Areas Inventory, 83% are smaller than 10 acres and 30% are less than | acre! These remaining prairie sites are found primarily along the northern and western edge of Illinois. The once vast Grand Prairie of central Illinois is all but gone. Currently, only 6% of the natural areas listed on the Illinois Natural Areas Inventory are afforded maximum protection against future changes in land use as dedicated Illinois Nature Preserves. Seventy-eight percent of Illinois prairie areas are classified as unprotected. The threats to these unprotected areas are numerous and include building and highway construc- tion, railroad maintenance, grazing, and cemetery mowing. Seventy-three percent of these prairie areas are likely to experience major threats within five years, and 9% are in immediate danger. The best examples of prairies in imminent danger are the hill prairies of Illinois. Although hill prairies were once thought to be among the more secure prairie types because their soils are poorly suited for plowing, a century of neglect is jeopardizing these remnant prairie sites. Invasion by woody species has reduced the size of Illinois hill prairies by an average of 50% during the past 50 years. This trend continues into the 1990s. Sparse biological data indicate that this loss in area has been accompanied by a loss in the biological diversity of hill prairie species during this period. Because of their small sizes and fragmented nature, Illinois’ remnants of the tallgrass prairie lack the full complement of natural processes that operate at large ecological scales. Prairies developed and were main- tained under the influence of three major abiotic factors: climate, grazing, and fire (Anderson 1982). Natural processes such as landscape-scale fires and grazing by large native mammals are no longer natural components of Illinois prairie. In addition, human land use has led to ecosystem changes other than outright habitat loss and fragmentation that threaten the biological integrity of some sites. These changes include drainage of surrounding agricultural lands, the input of pollutants (perhaps most importantly, nitrog- enous pollutants), climate change, and the introduction of cattle and numerous other non-native plants and animals. Without detailed studies of the direct effects of these changes, however, it will be difficult to assess their effects in any specific manner. With such dramatic changes to Illinois prairies, we do not expect them to function as natural ecosystems. Nonetheless, they represent a major component of our natural heritage and provide habitat for numerous plant and animal species that could not otherwise exist in Illinois. The tallgrass prairie has been called “the most diverse repository of species in the Midwest [and] .. . habitat for some of the Midwest's rarest species” (Chapman et al. 1990). With respect to plants, it appears that most remnant prairie sites are so small that there is a high potential for future species loss. At present, most true prairie species are found on rela- tively few sites. Unfortunately, few sites have under- gone repeated surveys to document whether our prairie sites are losing diversity. However, both plant and animal evidence suggests that most of our small prairie preserves provide refuge for only a small subset of the total biological diversity that may be found locally. _____ PRAIRIES Thus, it is vital that remaining unprotected sites become protected to ensure against further species loss. Birds are probably the most studied group of organisms on prairies. Several Illinois bird population studies, beginning in the mid-1800s and continuing through 1989, have provided insight into population trends. A long trend in decreasing abundance of nearly all grassland birds is continuing through to the present. This decline is exemplified by the prairie-chicken, a once common bird in Illinois that is now on the verge of extirpation within the state. Several thousand species of insects must have origi- nally inhabited the vast Illinois prairie. Fortunately, most seem to have survived the near total destruction of their pre—European settlement habitats. A majority of these animals inhabit a variety of humanized habitats, such as pastures, hayfields, parks, yards, and fencerows. Isolated populations of prairie-dependent insects on small, widely scattered prairie remnants contend with excessive edge effects and the high extinction rates associated with island-dwelling organisms. Having lost more than 99.99% of their presettlement habitats, this group of remnant-requiring animals is clearly vulnerable to the ongoing alteration of the Illinois landscape. Studies are currently under way to address the issue of insect persistence on prairie remnants. A number of prairie species (five mammals, four birds, three insects, five plants) have been extirpated from Illinois within historic time. Additional species (117) have become so rare that they are listed as endangered or threatened. Finally, the numbers of individuals of the surviving prairie species are very small compared to the numbers living in 1820, although no precise figures are available. This poses a serious threat with respect to vulnerability to extinction through chance events, as well as vulnerability to genetic problems associated with small population sizes, although little direct evidence to address this issue has been collected. Another consideration is that about 27.5% of the vascular plants growing spontaneously in Illinois are not native. These pose serious threats to the continued existence of the native flora and fauna of prairies. Reports of weedy plant, noxious insect, and mamma- lian pests are increasing in all habitats throughout the United States. Illinois prairies are no exception. We are dedicating more and more of our management time and resources in an effort to control species invading and degrading our prairie habitats. This issue will continue to be the primary threat to Illinois prairies through the remainder of the 20th century. GENERAL DESCRIPTION Grasslands are biological communities in which the landscape is dominated by herbaceous vegetation, especially grasses; they contain few trees or shrubs. Approximately 32 to 40% of the world’s land surface is, or was, covered by grasslands (Burton et al 1988, Groombridge 1992). Notable examples include the prairies of North America, the llanos of northern South America, the pampas of Argentina, the steppes of central Asia, the veldt of Africa, and the grasslands of Australia. Grasslands are the largest vegetation type in North America, covering approximately 15% of the land area, and prairies are the most abundant type of grassland on the continent (Burton et al. 1988). Prairies form a more or less continuous, roughly triangular area that extends from Alberta, Saskatchewan, and Manitoba southward through the Great Plains to southern Texas and adjacent Mexico and from western Indiana westward to the foothills of the Rocky Mountains (Risser et al. 1981; Madson 1982; Farney 1980; Weaver 1954, 1968) (Figure 1). This region is approximately 2,400 miles from north to south and 1,000 miles from east to west, covering 1.4 million square miles. Because of the rain shadow effect of the Rocky Moun- tains, which intercepts the eastward flow of moist air from the Pacific Ocean, there is a gradual increase in average annual precipitation from west to east, and this is reflected in the types of prairies found in central North America (King 1981a, b). Precipitation is about 10” to 15” a year in the western part of the prairie region, and the dominant vegetation is short-grass prairie. In the middle of the prairie region, annual rainfall ranges from 15” to 25”, and the mixed- or mid-grass prairie occurs. Toward the eastern part of the prairie region, rainfall is between 25” and 40” a year, and this is the domain of the tallgrass or true prairie. Today, these three prairie types correspond to the rangelands of the Great Plains (short-grass prairie), the wheat belt (mid- grass prairie), and cornbelt (tallgrass prairie). There is also a dramatic decrease in mean annual temperatures from south to north in the prairie region. Formation of Prairies Prairies are one of the most recently formed ecosys- tems in North America (Axelrod 1985). The tallgrass prairie in Illinois was formed following the most recent period of the Pleistocene glaciation. Based on the evidence of fossil pollen grains, prairie first appeared in central Illinois about 8,300 years ago (King 198 1a, b). Prairies developed and were maintained under the influence of three major abiotic factors: climate, grazing, and fire (Anderson 1982, 1991). Occurring primarily in the central part of North America, prairies are subject to extreme ranges of temperatures, with hot summers and cold winters. There are also great fluctuations of temperatures within growing seasons. Droughts are also characteristic of the climate in the prairie regions. These droughts may last only one or two months or continue for several years. Cyclic droughts also occur every 30 years or so. Before intervention by humans of European descent, wildfires occurred regularly in the prairie regions. Any given parcel of land probably burned once every one to five years. These fires moved rapidly across the prairie, and damaging heat from the fire did not penetrate the soil to any great extent. A considerable portion of the aboveground biomass of a prairie was consumed each year by the grazing of a Ls Y ty Z| \ isp don tb \ ae oh \ woe 4 ‘ Ly) ) FE=j Annual Grassland ey] Bunchgrass Steppe : CM North Mixed-grass " 7 Freie \ [II] shortgrass Proine [Ej soutnern Mixed-grass Prairie [_]totirase Proirie [Zsrruve and Grassiand [= ]oesert Grassiond ISM ond Grassiond Figure 1. Major grassland types of the United States, Canada, and Mexico (reprinted from Risser et al. 1981). PRAIRIES wide range of browsing animals, such as bison, elk, deer, rabbits, and grasshoppers. Prairie plants are adapted to these stresses by largely being herbaceous perennials with underground storage/perennating structures, growing points slightly below ground level, and extensive, deep root systems. The three abiotic factors of climate, grazing, and fire are important to keep in mind when formulating management practices for today’s prairie remnants. In later discussions, grazing is mentioned as being a disturbance factor in prairie remnants, but this refers only to grazing by domestic livestock, which has a quite different impact than the free-ranging grazing of native large mammals. Prairies are complex ecosystems in which plants, grazing mammals, burrowing animals, insects, fire, and climate interact in balance. In agricultural terms, the tallgrass prairie sustains high productivity while building and maintaining soil (Chapman et al. 1990). Extent of Original Prairie Illinois lies within an eastward extension of the tallgrass prairie called the prairie peninsula, which was, before settlement by Europeans, bounded on the north, east, and south by deciduous forests (Transeau 1935). At one time Illinois, the Prairie State, was about 60% prairie, found mainly in the northern two-thirds of the state. Forests were generally restricted to stream banks and the northwestern and southern portion of Illinois. The extent of Illinois presettlement prairie is well documented. A map was generated from the original government land survey records showing the distribu- tion of forests and prairies in Illinois (Anderson 1970) (Figure 2). This map was digitized by Iverson (1988, 1989), and geographic information system software was used to estimate that in 1820 Illinois had approxi- mately 21.6 million acres of prairie, or about 61.2% of the land area. The estimated amount of prairie that existed in each county in 1820 is shown in Figures 3 and 4; all but nine of the 101 counties in Illinois are shown as having at least some prairie habitat. Some scientists believe these figures underestimate the extent of prairie in Illinois prior to European settle- ment. For example, although no prairie acreages are listed by Iverson (1989) for nine counties in southern Illinois, the natural divisions occurring in these counties had at least some small prairie openings (Schwegman 1973). Another uncertainty concerns the recording of savannas on the original land surveys, because savannas have scattered trees with a prairie- like ground cover (Nuzzo 1986). _____ PRAIRIES [__]| PRAIRIE Figure 2. Distribution of forest and prairie in Illinois about | 820 (adapted from Iverson 1989). PRAIRIES ______ Changes in Land Use of Prairie In an astonishingly short period, roughly between 1840 and 1900, a vast amount of tallgrass prairie was destroyed. At present, only io of 1% of the original prairie remains (Figure 4). The early European settlers, being originally from forested regions in Europe and subsequently eastern North America, found the prairies to be rather frightening due to the hordes of insects, intense summer heat and high humidity, bleak windy winters, and periodic raging prairie fires. Because no trees grew on the prairies, the settlers at first considered the prairies to be unsuitable for crop plants. This, plus the need for construction timber and firewood, prompted the settlers to build their homes at the edges of the prairie, in prairie groves (islands of woods surrounded by prairie), and along wooded streams. It was not long, however, before the settlers discovered that the prairie soil was more fertile than forest soil— actually among the most productive soils in the world HB > 90% BB 30-89% EH 70-79% ER 60-69% fj 50-59% 40-49% [=] 30-39% [=] 20-29% [=] 10-19% (_] <10% Figure 3. Percentage of each Illinois county that was prairie in 1820 (Source: Iverson 1989). (Bogue 1968). A difficulty was that the prairie sod was so dense with tangled roots and deep that available plows were not able to break it easily. Prairie sod could not be broken easily until 1837, when John Deere, living in Grand Detour, Illinois, invented the self- scouring, steel-bladed plow. It can be said that the economic development of Illinois depended on the conversion of prairie soil to agricultural and eventually urban uses. In terms of overall land use, Illinois ranks 49th among the 50 states in the percentage of natural vegetation remaining (Klopatek et al. 1979). It is impossible to document today exactly how rapidly the prairies were plowed. One estimate is that 3.3% of the prairies in the state were plowed each year (Page 735,600 720,900 102,400 30.0 ge 92 670 & ei 307,200 15.0 Ea 126,600 /5.6 “mm “Ld 317,900 00 05 170,700 12.0 Figure 4. Changes in Illinois prairie acreage by county. The first number is the number of acres of prairie in 1820; the second is the number of acres of high-quality prairie remaining in 1976. Data for 1820 from Iverson (1989); 1976 data from White (1978). and Jeffords 1991). Only a few contemporary accounts lamented the destruction of the prairies. Robert Ridgway, the noted pioneer of ornithology in Illinois, related that in 1871 Fox Prairie (Richland County) was a large rolling plain of uninterrupted prairie 6 miles broad by 10 miles long but that by 1883 only 160 acres remained, the rest being covered by farms with cottages, fields, and orchards (Ridgway 1889). Herre (1940) wrote that when he returned to Illinois in the 1890s most of the prairies he had seen earlier had disappeared. ASSESSMENT OF CRITICAL INDICATORS Habitat Prairies Remaining in Illinois. In 1976 Illinois Natural Areas Inventory crews searched aerial photo- graphs of each county in Illinois for high-quality natural areas (White 1978); this was followed by field work to examine potential sites. The survey concluded that only 0.01% of the original prairie existed in 1976 (Schweg- man 1983). The workers located 253 sites containing 2,352 acres of high-quality prairie (Figure 5). Ona statewide basis, it is estimated that 52.9% of the land in Illinois was converted to agricultural land between 1820 and 1980, and 3.1% was converted to urban areas (Iverson 1988). In addition, 2.6% of the land in the state changed from prairie to forest; this was presum- ably due to the cessation of widespread prairie fires. Land-use changes have been calculated for two counties in Illinois using geographic information system software (Iverson and Risser 1987). The land in Lake County was originally 29.2% prairie, or 102,400 acres. Of this amount, 65% was converted to agricultural use and 27% to urban use. In Jackson County, prairie originally accounted for only 2% of the land area. Seventy-five percent of this small amount of prairie is now used for agriculture and 6% for urban uses. Figure 4 shows the number of acres of prairie in each Illinois county in 1820 and the number of acres of high- quality prairie (Illinois Natural Areas Inventory grade A and B) in 1976. Grade A is used for natural commu- nities that have a structure and composition that are stable and that show little or no effect of disturbance by humans. Grade B is used for former grade A communi- ties that have either been lightly disturbed or moder- ately to heavily disturbed but which have recovered significantly. Not included in the data from which the map was made are the numerous grade C prairies, which have been moderately to severely disturbed to the extent that the original structure was destroyed and the species composition has been changed significantly. PPFRAVPUES nn A few examples illustrate these drastic changes in prairies. Cook County had approximately 521,900 acres of prairie in 1820, but only 391 acres of grade A and B prairie remained in 1976. McLean County, which had 669,800 acres, now has only 5 acres. Champaign County, which once had 592,300 acres of prairie, was thought to have none in 1976. Since 1976, however, a l-acre dry-mesic savanna with mostly prairie vegetation was found in the extreme northeast- ern part of the county. The Nature Conservancy (Chapman et al. 1990) estimates that more than 99% of the tallgrass prairie east and north of the Missouri River has been destroyed, and only about 15% remains to the west and south of this river. The remaining high-quality (grade A and B) prairies tend to be found in very small patches (Figure 6). Of Ea sites Sa ba Pre Figure 5. Locations of grade A and B natural areas that contain prairie (Source: Illinois Natural Areas Inventory). 120 100 A) All Prairies Number of Sites 0-1 1-5 5-10 10-20 20-50 50-100 >100 B) Black Soil Prairies Number of Sites 0-1 1-5 5-10 10-20 20-50 50-100 >100 30 C) Sand Prairies 20 Number of Sites 0-1 1-5 5-10 10-20 20-50 50-100 >100 D) Hill Prairies Number of Sites 8 0-1 1-5 5-10 10-20 20-50 50-100 >100 20 8 E) All Other Prairie Types F i 10 ® ce} E = wos i) o-1 i-S 5-10 10-20 20-50 50-100 >100 Acreage Category Figure 6. Number of grade A and B prairies by prairie type and size category (Source: Illinois Natural Areas Inventory). PRAIRIES the 253 prairie sites identified by the Illinois Natural Areas Inventory, 83% are smaller than 10 acres and 30% are less than one acre! All remnants of the tallgrass prairie, in Illinois and elsewhere, lack the full complement of natural processes that operate at large scales, such as landscape fires, grazing by large mam- mals, and natural migrations of species and changes of species composition with fluctuations in rainfall. Types of Prairies in Illinois. The natural landscape of Illinois can be divided into 14 natural divisions, based on topography, glacial history, bedrock, soils, and distribution of plants and animals (Schwegman 1973) (Figure 7). Various kinds of prairies occurred in each of these natural divisions. The prairies of Illinois were by no means a homogeneous stand of grasses and forbs. The Natural Areas Inventory (White 1978) recognizes six main subclasses of prairie: black soil prairie, sand prairie, gravel prairie, dolomite prairie, hill prairie, and shrub prairie. Further divisions are made based on soil moisture classes, yielding 23 prairie types in Illinois (Table 1). These different prairie types are the result of variations in soil moisture, soil composition, geological substrate, glacial history, and topography. Biodiversity of Prairies The tallgrass prairie is “the most diverse repository of species in the Midwest [and] . . . habitat for some of the Midwest’s rarest species” (Chapman et al. 1990). It is rather difficult to give a total number of species that occur in Illinois prairies. Because the tallgrass prairie ecosystem is recently evolved, there are few endemic species; few prairie species are restricted to the prairie habitat. Most prairie species also occur outside the prairie region in habitats other than prairies. Prior to European settlement, the landscape of the tallgrass prairie in Illinois was a complex matrix with special- ized communities embedded in the prairie — fens, pannes, sedge meadows, marshes, ponds, kames, sand blowouts, savannas, and prairie groves. The borders between these communities and the prairie fluctuated on both short- and long-term bases depending on rainfall, drought, and fire frequency. This ever- changing matrix adds to the problem of placing some species into the “prairie species” category. For this discussion we include all species that occupy or utilize during some stage of their life cycle the types of habitats recognized as prairie by the Illinois Natural Areas Inventory (Table 1); excluded are species restricted to open grass, sedge, and forb-dominated communities classified as wetlands, such as sedge meadows and fens. _______ PRAIRIES | 1 | Wisconsin Driftless Division | 2 |! Rock River Hill Country Division a Freeport Section b Oregon Section wt 3 Northeastern Morainal Division eas a Morainal Section b Lake Michigan Dunes Section ¢ Chicago Lake Plain Section d Winnebago Drift Section 4 Grand Prairie Division a Grand Prairie Section b Springfield Section c Western Section d Green River Lowland Section e Kankakee Sand Area Section Upper Mississippi River and Illinois River Bottomlands Division a Illinois River Section b Mississippi River Section [6 | Illinois River and Mississippi River Sand Areas Division a Illinois River Section b Mississippi River Section | 7 Western Forest-Prairie Division a Galesburg Section b Carlinville Section 8 Middle Mississippi Border Division a Glaciated Section b Driftless Section 9 Southern Till Plain Division a Effingham Plain Section b Mt Vernon Hill Country Section 10 Wabash Border Division EE a Bottomlands Section b Southern Uplands Section c Vermilion River Section VW Ozark Division a Northern Section b Central Section c Southern Section 2 Lower Mississippi River Bottomlands Division a Northern Section b Southern Section Lz 13 Shawnee Hills Division Lia] a Greater Shawnee Hills Section b Lesser Shawnee Hills Section 4 Coastal Plain Division a Cretaceous Hills Section b Bottomlands Section Figure 7. The natural divisions of Illinois (reprinted from Schwegman 1973). _ PRAIRIES Table 1. Number of acres of various prairie types in Illinois. Data for 1978 from White (1978); 1992 data from Illinois Natural Areas Inventory database. 1978 1992 Blacksoil Prairie Dry prairie 30.4 30.4 Dry-mesic prairie 299.3 289.7 Mesic prairie 803.9 622.1 Wet-mesic prairie 1,054.3 1,050.3 Wet prairie 1,041.3 818.0 Sand Prairie Dry sand prairie 926.8 924.3 Dry-mesic sand prairie 672.5 671.0 Mesic sand prairie 3973 389.2 Wet-mesic sand prairie 76.2 76.2 Wet sand prairie 300.7 300.7 Gravel Prairie Dry gravel prairie 83.2 ghNES) Dry-mesic gravel prairie 50.6 48.9 Mesic gravel prairie rae oH | Dolomite Prairie Dry dolomite prairie 29.6 29.6 Dry-mesic dolomite prairie 9.0 9.0 Mesic dolomite prairie 37.0 37.0 Wet-mesic dolomite prairie 39.7 S97 Wet dolomite prairie 5.0 5.0 Hill Prairie Loess hill prairie 463.0 459.1 Glacial drift hill prairie 51.5 S15 Gravel hill prairie 14.7 14.7 Sand hill prairie a, ayy Shrub Prairie 180.0 180.0 Plants. Using various sources, Widrlechner (1989) compiled a list of 862 species of plants native to prairies of the midwestern United States. The Illinois Plant Information Network (ILPIN) is a computerized database listing life-history, habitat, taxonomic, and distributional information available on the vascular flora of Illinois (Iverson 1992). The ILPIN database records 851 species of plants native to Illinois prairies. Examining the diversity of Illinois prairies by county (Figure 8) shows that this diversity differs from region to region. The Chicago region, with its large diversity of prairie types, contains many prairie species. Many species also occur along the Mississippi and Illinois rivers. Somewhat surprising is the large number of prairie species in extreme southern Illinois that occur in the numerous small prairie openings there. This level of plant diversity, however, is not likely to be found on any single prairie. A general pattern of increasing diversity with size of a habitat patch, referred to as the species/area curve, is commonly observed across a wide range of taxonomic groups and habitat types (Gleason 1922, MacArthur and Wilson 1967, Harris 1984). The species/area curve observed in the flora of prairies suggests that patches larger than 10 acres contain most of the local diversity of plants, approximately 100 species (Figure 9). Unfortunately, fewer than 17% of all remaining prairies in Illinois are above this size threshold (Figure 6). Nevertheless, a substantial amount of floristic diversity is preserved in small habitat patches since the mean patch size for grade A and B prairie remnants in Illinois is quite small. The apparent local maximum level of diversity (100 species), though, is far below what may be found in most counties in Illinois (Figure 8). Perhaps this 1s because most species are uncommon, as demonstrated by two floristic surveys of small prairie fragments in Illinois and Indiana (Betz and Lamp 1989, 1992). In both studies, most species were found in fewer than four sites (Figures 10, 11). Therefore, the complement of species found on any given prairie remnant is likely to be individualized and somewhat unique. Any further loss of prairie fragments represents the potential for a serious erosion of the floristic diversity of the state because of the relatively few good habitat patches in which many of these species are currently found. Birds. As one might expect, the dramatic change in the landscape after European settlement resulted in equally dramatic changes in bird populations. Several Illinois bird population studies, beginning in the mid-1800s and continuing through 1989, have provided insight into these changes. At first the change from prairie to agricultural land caused an increase in several bird species with the formation of pastures and hayfields—that is, secondary grasslands (Graber and Graber 1963). These secondary grassland habitats became acceptable breeding grounds for a majority of prairie birds (Graber and Graber 1963). The prairie-chicken especially benefited from this new combination of food and cover as well as the decrease in animal predators. It is thought that the dickcissel, another prairie bird whose numbers in- creased early on, actually preferred these secondary grasslands over the original prairie (Kendeigh 1941, Graber and Graber 1963, Zimmerman 1971). Despite increased populations of some prairie birds throughout Illinois, however, Graber and Graber (1963) found that population changes were negligible for most species between 1909 and 1956. Some species considered very common or abundant before 1900 decreased slightly in numbers early in this o - FS nm ow 5% cg ® - Or ® ‘OS eM 2 oO Be a ze oS = prairie plant species EES 351-400 Native Bea GT 25 Endangered and threatened plant species Sa Feces non-native prairie plant species (top right), and endangered Figure 8. The number of prairie plant species (top left), and threatened plant species (bottom) in each Illinois county (Source: Illinois Plant Information Network). 10 200 150 100 Number of Species + Hill Prairies ® Cemetery Savannas ul ° 0 10 20 30 40 Acres Figure 9. Number of species censused in prairie remnants of various sizes, demonstrating that diversity of prairies increases with size (Sources: Evers, unpublished data; Betz and Lamp 1992; Betz and Lamp 1989). century, and others have been declining sharply (Figure 12). A decline in almost all prairie bird populations in Illinois occurred from 1967 to 1989 (United States Fish and Wildlife Services breeding bird survey, unpub- lished data) (Table 2). Although the cause of this decline is not fully known, it is thought to be related to the ongoing depletion of Illinois grassland habitat. A decrease in hay production (Illinois Agricultural Statistics Service 1988, 1989) coupled with pasture reduction (U. S. Department of Commerce Bureau of the Census 1989) has resulted in a loss of secondary grasslands on top of the depletion of the original prairie. This overall loss of Illinois grassland habitats is partially responsible for the current fragmented landscape. As a result of habitat fragmentation, changes have occurred that may have important consequences for breeding birds. Most obviously, a reduction in habitat results in a reduction of individuals, local populations, or perhaps even species. Less obvious but also important to breeding birds is that smaller habitats may lack essential resources and provide less of a buffer in the event of natural catastrophes or predators. Although only three species of prairie birds have been eliminated from Illinois, 13 more species are considered threatened or endangered, mainly because of habitat loss. One of the birds included on the endangered list has experienced an enormous decline in numbers due more to the invasion of its habitat by a non-native species PRAIRIES 120 100 80 NUMBER OF TAXA 1 296646576 7.89" 1011112 18 14.415116 NUMBER OF SITES Figure 10. Number of sites in which each of 238 native taxa were found in a survey of 16 remnant prairie and savanna cemeteries in Illinois and Indiana (Source: Betz and Lamp 1992). 40 : 30 = WL O 20 fo wi a 5 aa ) K-NOMFTNORDBMOK-ANNTHORADBO NUMBER OF SITES Figure 11. Number of sites in which each of 180 native taxa were found in a survey of 29 remnant black soil prairies in Illinois and Indiana (Source: Betz and Lamp 1989). than to a reduction of habitat. In 1860, the state of Illinois was home to 10 million greater prairie-chickens (Westemeier 1983, Westemeier 1990, Westemeier and Edwards 1987), a species that had survived in large numbers over several thousand years despite native predators such as coyotes, skunks, and opossums. Although much of the prairie was gone by 1912, Relative Abundance —_____ PRAIRIES Eastern Meadowlark Dicksissel Grasshopper Sparrow Bobolink Henslow's Sparrow Red-winged Blackbird Greater Prairie Chicken 40 —+*— Upland Sandpiper 30 20 0 1900 1920 1940 1960 1980 2000 Figure 12. Twentieth century trends in populations of grassland birds cited to have been abundant or very common prior to 1900 (Source: Herkert 1989). prairie-chickens still occupied 92 counties but quickly decreased in numbers with the release and establish- ment of ring-necked pheasants (Figure 13). As of 1989, there were less than 100 prairie-chickens in Illinois (R. Westemeier, Illinois Natural History Survey, Champaign, personal communication). Sanctuaries were established in areas around the state to insure that suitable habitat for prairie-chickens would always exist. Unfortunately, these sanctuaries are also desirable for pheasants, which have become the greatest threat to prairie-chickens. The greatest problem associated with the coexistence of prairie-chickens and pheasants appears to be the result of hen pheasants “parasitizing” or laying eggs in the nest of prairie-chickens. Pheasant eggs hatch about two days earlier than those of prairie-chickens, some- times causing the hen to leave the nest before her own chicks have hatched. Even if both eggs are hatched, the problem of harassment of prairie-chicks by the larger pheasant chicks can occur. The survival of any species depends on successful reproduction, and the prairie- chicken has not been able to effectively coexist with the pheasant. Insects. Vertebrates constitute but a small fraction of the animal species found in terrestrial ecosystems. Most animals are invertebrates, and most invertebrates Table 2. Relative abundance of various prairie bird species in Illinois before 1900 and changes in species populations from 1967 to 1989. A = abundant; VC = very common; C = common. Priorto USFWS % change Species 1900! 1967-19897 Eastern meadowlark A -67.0 Dickcissel A —46.7 Grasshopper sparrow A —56.0 Bobolink A -90.4 Henslow’s sparrow A * Red-winged blackbird Ve -18.8 Greater prairie chicken VC ae Upland sandpiper VC -16.8 Vesper sparrow c +12.1 Horned lark € 0.0 Field sparrow (C; —52.6 Song sparrow Cc —29.3 Savannah sparrow Cc 58.9 American goldfinch € 42.8 Common yellowthroat Cc -8.8 Sedge wren Cc —22.5 ' Based on the work of Nelson (1876) and Ridgway (1889, 1895). ? Estimated population change within Illinois between 1967 and 1989 based on the United States Fish and Wildlife Service’s breeding bird survey (USFWS, unpublished data). *Present on too few routes for accurate trend analysis. are insects. An estimated 17,000 species of insects occur in Illinois (Post 1991); several thousand of these must have originally inhabited the vast Illinois prairie. Fortunately, most seem to have survived the near total destruction of their pre-European settlement habitats. A majority of these animals inhabit a variety of human- ized habitats, such as pastures, hayfields, parks, yards, and fencerows. Some insect species have actually benefited from the alteration of their presettlement plant communities and can often be found in exagger- ated numbers throughout Illinois (R. Panzer, Northeast- ern Illinois University, personal communication). A smaller but significant number of prairie insect species have not managed to adapt to the modern Midwestern landscape (for examples, see Table 3). These “conservative” species are very discriminating in their choice of habitats and are rarely found outside of the context of their native plant communities. Isolated as small populations on small, widely scattered prairie remnants, these species must contend with excessive edge effects and the high extinction rates associated with island-dwelling organisms. Having lost more than 99.99% of their presettlement habitats, this group of remnant-requiring animals is clearly vulnerable to the ongoing alteration of the Illinois landscape. $$ PRAIRIES JASPER COUNTY - BOGOTA AREA 8 8 8 8 SPRING COUNTS (Total Birds) PRAIRIE CHICKENS O93 Ss. or oo «vl 73.75 «ar 73 “St Figure 13. Spring counts of prairie-chickens and pheasants on the Bogota Study Area, Jasper County, Illinois, 1963-1982. Pheasants are represented by the shaded area above the prairie-chicken population (reprinted from Westemeier 1983). Insect surveys have been conducted within a variety of humanized habitats and on 56 Illinois prairie and savanna remnants since 1982 (R. Panzer, unpublished data). The primary focus of this study has been on leafhoppers, froghoppers, butterflies, root-borer moths (Papaipema species), and flower moths (Schinia species), groups that are generally reported to include inordinately high numbers of prairie-dependent species. Grasshoppers, grouse locusts, katydids, walking sticks, stinkbugs, shieldback bugs, treehop- pers, and bumblebees, insects that are widely reported to be tolerant of habitat alteration, were also consid- ered. The primary objectives of this study were to generate estimates of conservatism for each group and to determine the status, distribution, and site size requirements of the conservative species in northern Illinois. Six hundred forty species belonging to the groups surveyed have been recorded within northern Illinois in the past 100 years. Eighty-five percent of these insects have been relocated since 1982 (Figure 14). At least three-quarters have been recorded in one or more humanized habitats and can currently be considered to be secure (Figure 15). Roughly 25% of the species considered here have been found to be restricted to prairie and savanna remnants. Roughly two-thirds of these conservative species are seemingly secure, surviving on at least a dozen protected sites. Approxi- mately one-fifth are known from fewer than six sites and are clearly imperiled. Prominent examples include moths such as the Eryngium root-borer (Papaipema eryngit) and the loosestrife root-borer (Papaipema Table 3. Insect species previously reported to occur in the prairie area within Illinois Beach State Park that are no longer found there (R. Panzer, personal communication). Leafhoppers Hecalus rotundus Flexamia delongi Polyamia compacta Hebecephalus signatifrons Hebecephalus cruciatus Deltocephalus gramus Euscelis sahlbergi Limotettix parallelus Paraphlepsius altus Chlorotettix obsensus Chlorotettix rugicollis Chlorotettix brevidis Butterflies Hesperia ottoe Callophrys irus Moths Schinia indiana lysimachia), both of which are known to survive only on one or two protected sites. A small number of species, such as the Indiana flower moth (Schinia indiana), the Harris checkerspot (Chlosyne harrisii), and the Dakota skipper (Hesperia dacotae), have not been relocated and likely have been extirpated from Illinois. Most of the prairie and savanna remnants in Illinois are very small and widely spaced, precluding the exchange of species and individuals between sites. The data presented here suggest that most Illinois remnants continue to support prairie-dependent species. Sites of 100 acres have been found to support as many prairie- dependent species as do sites that are 10 times larger, suggesting that losses on sites within this size range have been slight (Figure 16). Species diversity de- creases dramatically at sites smaller than 100 acres. Only 3 of the 253 (1.2%) grade A and B prairies in Illinois are larger than 100 acres. Truly small remnants appear to have lost species (Figure 16). That there have, in fact, been losses in species diversity on even the largest sites is similarly clear. Two butterfly, one moth, and a dozen leafhopper species, all of which were recorded within the large prairie that has since been protected as Illinois Beach State Park, have not been seen in many years and are presumed to have been extirpated from this site (Table 3). Finally, parallel studies within the large (1,000 acre) Fermilab Prairie Restoration indicate that prairie- _______ PRAIRIES ‘Species Not Found 1982-1992 3007 J Species Recorded 1982-1992 Le) fo} oO 100 Number of species ii 6 = Stink bug Shieldback bug Leafhopper Figure 14. Among prairie insect species described in the early 20th century in northern Illinois, number of species in various taxonomic groups that were either found or not found in northern Illinois between 1982 and 1992 (Source: R. Panzer, unpublished data). dependent insect species cannot be expected to return unaided to prairie plantings. Despite its “huge” size, this prairie recreation contributes little to the conserva- tion of prairie butterflies in Illinois (Figure 16). In summary, available data suggest that, although a majority of the prairie insects have adapted to the modern Illinois landscape, scores of species have not. The conservation of the remnant-dependent animals can clearly be best served by preserving the prairie remnants upon which they depend (Panzer 1988). It has been found that hill prairies in lowa, which contain the largest remaining tracts of prairie in that state, serve as significant refugia for butterflies and other inverte- brates (Orwig 1992). Hill prairies in Illinois need to be studied to see if the same happens in our state. Endangered Species. Because 99.99% of the natural prairies in Illinois have been destroyed, the numbers of individuals of all prairie plants and animals are very small today compared with 1820, although no precise figures are available. Many species have become so rare that they are listed as endangered or threatened. Currently, 497 species are listed as endangered or threatened in Illinois (Illinois Endangered Species Protection Board 1990); 401 are endangered and 96 are threatened (J. Herkert, personal communication). Of 300 E) Conservative Species Facultative Species nN oO co i fo} oO Number of species : £ co) Grouse locust Walking stick Figure 15. Among insect species of various groups found in prairies in northern Illinois, proportion occurring almost exclusively in prairies (conservative species) and proportion often found in other habitats as well (facultative species) (Source: R. Panzer, unpublished data). Species abundance 0 100 200 300 400 500 600 Size (Hectares) Figure 16. Relationship between species diversity and prairie area for leafhoppers and butterflies. Diversity generally increases with increasing prairie size (Source: R. Panzer, unpublished data). 700 Table 4. Total number of endangered (E) and threat- ened (T) species in Illinois and number of these that are prairie species. TotalE TotalT PrairieE Prairie T Fishes 15 15 0 0 Reptiles & amphibians 7 5 2 2 Birds 37 6 10 3 Mammals i 3 1 0 Invertebrates 41 7 1 2 Plants 296 60 77 18 these species, 116 (23%) occur on prairies. These species are summarized by group in Table 4, and the individual species are listed in Table 5. The distribution of the endangered and threatened (E & T) plant species is not uniform throughout the state (Figure 8). By far the largest concentration is in the Chicago region, largely as a result of high ecological diversity; the western part of the state also has a number of E & T prairie species, mostly in hill and sand prairies. About half of the plant species listed in Table 4 are essentially restricted to sand prairies, dunes, or beaches. Particularly striking is the dearth of E & T species in central Illinois, due to the nearly total loss of habit; also, few E & T plant species occur in blacksoil prairies. As an example, the prairie white-fringed orchid (Platanthera leucophaea) was once widespread on the blacksoil prairies and has been reported histori- cally from 33 counties. Today it is known only from mostly small populations in eight counties, and some of these are under threat by non-native species, unscrupu- lous collection, and lack of proper management practices (Herkert 1991a, b). Of the 45 species of the orchid family of plants (Orchidaceae) native to Illinois, 19 (42%) are listed as endangered or threatened. Other E & T plant species were likely always uncommon in Illinois, being at the edge of their natural ranges. Some examples include Mead’s milkweed (Asclepias meadii), large-flowered beard-tongue (Penstemon grandiflorus), and primrose violet (Viola primulifolia). Silvery bladderpod (Lesquerella ludoviciana) and leafy prairie clover (Petalostemum foliosum) are widely disjunct from other populations of the species. Four taxa of plants are endemic to Illinois: Kankakee mallow (/liamna remota), Sangamon phlox (Phlox pilosa subsp. sangamonensis), decurrent false aster (Boltonia decurrens), and American thismia (Thismia americana). The last is likely extinct (see below), and PRAIRIES the second is restricted to prairies and forest openings along the Sangamon River in Piatt and Champaign counties. The Kankakee mallow, while not considered a prairie species, grows in gravel soils on an island in the Kankakee River, and some prairie species occur on the island. Decurrent false aster (Boltonia decurrens) was probably endemic to alluvial prairies and marshes along the Illinois and Mississippi rivers in Illinois. Today, this species no longer occurs in prairies per se. Several animals that occurred on the prairies have been extirpated from Illinois within historic time, such as the bison, elk, prairie wolf, mountain lion, and black bear (Hoffmeister 1989). Four birds that occurred on the prairies in Illinois were listed as extirpated by Bowles et al. (1980): whooping crane, sharp-tailed grouse, American swallow-tailed kite, and sandhill crane. The sandhill crane has since reappeared in the state, and the whooping crane and American swallow-tailed kite are very rare migrants (Bohlen and Zimmerman 1989). Extirpated prairie insects are the Dakota skipper, Indiana flower moth, and Harris checkerspot see Post 1991). As far as we know, only one plant species that occurred in Illinois prairies is both extirpated from Illinois and extinct. This plant, Thismia americana, was last seen in 1914 (Mohlenbrock 1983). Other prairie plant species that have been extirpated from Illinois but that occur in other states are Drummond rock cress (Arabis drummondii), wild blue larkspur (Delphinium carolinianum var. penardii), blanket flower (Gaillardia aestivalis), and running buffalo clover (Trifolium stoloniferum) (Post 1991). The lake-side daisy (Hymenoxys acaulis var. glabra) formerly was found in dolomite and gravel hill prairies, but the last naturally occurring population in Illinois was destroyed in 1981. However, plants from an Illinois population are in cultivation; unfortunately, this species must be cross- pollinated, and the cultivated plants represent the same breeding type. These cultivated plants have been crossed with plants from Ohio and Ontario to produce fertile offspring, which have been used in an attempt to reintroduce the species into natural areas in Illinois. Non-native Plant Species. A recent estimate (Post 1991) indicates that there are 2,068 species of vascular plants in Illinois. The most recent floristic manual (Mohlenbrock 1986) gives the total number of vascular plants known to be native or naturalized as 2,853. Using these figures, about 27.5% of the vascular plants growing spontaneously in Illinois were introduced from other regions, especially Europe, eastern Asia, and other parts of North America. Slightly different figures have been obtained using other sources of data _______ PRAIRIES Table 5. Endangered (E) and threatened (T) species of Illinois prairies. Intial data supplied by J. Herkert; plant list modified by Natural History Survey staff. Plants Agropyron subsecundum Artesemia dracunculus Asceplias lanuginosa Asclepias meadii Asclepias ovalifolia Asclepias stenophylla Astragalus crassicarpus var. trichocalyx Astragalus tennesseensis Beckmannia syzigachne Besseya bullii Betula populifolia Boltonia decurrens Botrychium simplex Bumelia lanuginosa Calopogon tuberosus Camassia angusta Carex atherodes Carex aurea Carex austrina Carex crawei Carex tonsa Castilleja sessiliflora Ceanothus ovatus Comptonia peregrina Corydalis curvisiliqua var. grandibracteata Cyperus grayioides Cypripedium calceolus var. parviflorum Cypripedium candidum Cypripedium reginae Drosera intermedia Eriophorum viridi-carinatum Erythronium mesochoreum Filipendula rubra Fimbristylis vahlii Heliotropium tenellum Hexalectris spicata Hudsonia tomentosa Hymenoxys acaulis var. glabra Hypericum kalmianum Juncus alpinus Juncus vaseyi Lactuca ludoviciana Lechea intermedia Lespedeza leptostachya Lesquerella ludoviciana Lycopodium clatatum Lycopodium dendroideum Lycopodium inundatum Microseris cuspidata Mirabilis hirsuta Oenothera perennis Opuntia fragilis Orobanche fasciculata Orobanche ludoviciana Panicum boreale Paspalum bushii Penstemon grandiflorus Petalostemon foliosum Phacelia gilioides Phlox pilosa subsp. sangamonensis 16 bearded wheat grass false taragon woolly milkweed Mead’s milkweed oval milkweed narrow-leaved green milkweed large ground plum Tennessee milk vetch American slough grass Kittentails gray birch decurrent false aster dwarf grape fern wooly buckthorn grass pink orchid wild hyacinth sedge golden sedge sedge sedge sedge downy yellow painted cup redroot sweetfern corydalis umbrella sedge small yellow lady’s slipper white lady’s slipper showy lady’s slipper narrow-leaved sundew tall cotton grass white dog-tooth violet queen-of-the-prairie Vahl’s fimbristylis slender heliotrope crested coralroot orchid false heather lakeside daisy Kalm’s St. John’s wort Richardson’s rush Vasey’s rush western wild lettuce pinweed prairie bush clover silvery bladderpod running pine ground pine bog clubmoss prairie dandelion hairy umbrella wort small sundrops | fragile prickly pear clustered broomrape broomrape northern panic grass hairy bead grass large-flowered beard tongue leafy prairie clover phacelia Sangamon phlox Aamo mm * SAmMMMMAM ws MH oY mo * * joo coMcoicoMesMeoMesMceMcoMcoMicsMcs Ma: Mc Meo Ma: Mcoll cs] les coMcoMcsMcoMcoMcoMcsMcoMesMcoMcolcom cel Platanthera ciliaris orange fringed orchid Platanthera clavellata wood orchid Platanthera flava var. herbiola _ tubercled orchid Platanthera leucophaea prairie white fringed orchid Platanthera psycodes purple fringed orchid Pogonia ophioglossoides snake-mouth Polanisia jamesii James’ clammyweed Polygala incarnata pink milkwort Polygonum careyi Carey’s heartsease Populus balsamifera balsam poplar Potentilla millegrana cinquefoil Ranunculus rhomboideus prairie buttercup Rubus setosus bristly blackberry Rudbeckia missouriensis Missouri orange coneflower Rumex hastatulus sour dock Sabatia campestris prairie rose gentian Salvia azurea subsp. pitcheri blue sage Sanguisorba canadensis American burnet Silene regia royal catchfly Silphium trifoliatum rosinweed Sisyrinchium atlanticum Sisyrinchium montanum Sphaeralcea angusta eastern blue-eyed grass mountain blue-eyed grass globe mallow Spiranthes lucida yellow-lipped lady’s tresses Spiranthes vernalis spring lady’s tresses Stylisma pickeringii Patterson bindweed Talinum calycinum fameflower Thismia americana thismia Tomanthera auriculata ear-leafed foxglove Tradescantia bracteata Triadenum virginicum Trifolium reflexum Trillium viride Viola primulifolia Viola viarum prairie spiderwort marsh St. John’s wort buffalo clover green trillium primrose violet plains violet Zigadenus glaucus white camass Amphibians Pseudacris streckeri Illinois chorus frog th subsp. illinoensis Birds Ictinia mississippiensis Mississippi kite E Circus cyaneus northern harrier E Tympanuchus cupido greater prairie-chicken E Coturnicops noveboracensis yellow rail E Laterallus jamalcensis black rail E Grus canadensis sandhill crane E Bartramia longicauda upland sandpiper E Tyto alba common barn owl E Asio flammeus short-eared owl E Lanlus ludovicianus loggerhead shrike E Spizella pallida clay-colored sparrow E Ammodramus henslowii Henslow’s sparrow iy Euphagus cyanocephalus brewer's blackbird T Mammals Lepus townsendii white-tailed jackrabbit E Reptiles Clemmys guttata spotted turtle E Kinosternon flavescens Illinois mud turtle E Heterodon nasicus western hognose snake T Invertebrates Hesperia ottoe ottoe skipper v Hesperia metea cobweb skipper st Atrytone arogos arogos skipper E * Federally threatened * jes l eo Mico Mic: Mico Mco Mes icc Merle! MecMcsmcMesMes Mer Mes Merl cole: Mes Mico Msc: Me: Mc) Mico McrMco lcs M colic Mc) Me: Meri cy] (Henry and Scott 1980, Reed 1988; see also the section on non-native species in the chapter on wetlands). In any case, the number of non-native species has increased dramatically with European settlement, from 10.2% in 1846 to something around 30%. Using species distribution information from the ILPIN database, one finds that non-native species are most prevalent in the Chicago region, western Illinois, and southwestern Illinois (Figure 8). Recently, the reality that non-native species can be disruptive of natural ecological communities has been reflected in the enactment of the Illinois Exotic Weed Act (Gould and Gould 1991). Non-native species can be divided into three catego- ries. The first are extremely serious weeds that outcompete native species and threaten to destroy natural plant communities in the prairies. The second category of non-native species that occur regularly in prairies are adapted to current climate and management practices, are not overly aggressive, and are not likely to further significantly change species composition or frequency in prairies. The third category includes species that will probably be eliminated with proper management practices. These are species that either persist from cultivation or are opportunistic in distur- bances in the prairies. Different prairies have different disturbance and management practices that affect the occurrence of non-native species. For example, black-soil cemetery prairies are different from other prairie remnants in that they often contain species that were planted as orna- mentals. In a study of 44 pioneer settler cemeteries on silt-loam soil, Betz and Lamp (1989) found a total of 180 native species, 73 non-native herbaceous species, 22 species of both native and non-native woody plants, and 13 species of cultivated forbs. In a subsequent study of 16 old settler savanna and sand prairie cemeteries, Betz and Lamp (1992) found 238 native prairie or savanna species, 22 species of woody plants, 54 species of weedy native or non-native herbaceous plants, and 14 species of cultivated forbs (Figure 17). A combined species list for three central Illinois blacksoil prairie pioneer cemetery nature preserves—Loda Cemetery, Prospect Cemetery in Paxton, and Weston Cemetery (K. Robertson, Illinois Natural History Survey, unpublished data), each about 5 acres—shows a total of 186 species, of which 46, or 24.7%, are non-native. The two most serious non-native species at Loda Cemetery are daylily (Hemerocallis fulva) and teasel PRAIRIES 29 Sites (Betz and Lamp 1989) Native Prairie Species Woody Species Non-Native Herbaceous Species Cultivated Forbs a ts |) 16 Sites (Betz and Lamp 1992) Figure 17. Proportion of taxa that are native and herbaceous, woody, non-native herbs (weeds), and cultivated forbs (weeds) on 29 black soil prairie remnants (top) and 16 sand and gravel prairie rem- nants (bottom) in Illinois and Indiana (Source: Betz and Lamp 1989, 1992). (Dipsacus laciniatus). Since 1978, these species have increased greatly, and one large colony of daylily has nearly divided the prairie in half, crowding out all native vegetation. Teasel is a good example of the necessity to understand the biology of a species before undertaking control measures. Because teasel is a biennial species, initial attempts at control involved hand-cutting the flowering stalks and leaving them in the prairie to add to biomass for burning the following spring. Unfortunately, enough stored energy remains in the cut stalks for seed to set (Solecki 1989, Glass 1991). Control measures now include transporting the cut stalks off site as well as very early spring burns (late January in 1993) when the winter rosettes are exposed and native plants are dormant. At Prospect Cemetery, the most detrimental non-native species are daylily, periwinkle (Vinca minor), white popular (Populus alba) (Glass 1992), cypress spurge (Euphor- bia cyparissias), and white and yellow sweet clovers (Melilotus alba, M. officinalis) (see Cole 1991). Fortunately, Weston Cemetery is mostly free from non- native plant species in this category. PRAIRIES Although teasel was introduced from Eurasia prior to this century (Werner 1975), it has only recently spread in Illinois to become a problem weed (Glass 1991, Solecki 1989). The expansion of both common and cut- leaved teasel appears to have been assisted by two phenomena. First, the location of population centers along interstate highway rights-of-way suggest that cut-leaved teasel moves with highway construction. Horticultural use of common teasel in floral displays at gravesites has resulted in numerous colonizations of cemetery prairies (Swink and Wilhem 1979). Cut- leaved teasel, a recent invader, was first recorded in Missouri in 1980 near Kansas City. Vast populations can now be found along Illinois roadsides where there were few or no populations only 5—10 years ago (Glass 1991, Solecki 1989). In moister prairies, especially in the Chicago region, common buckthorn (Rhamnus catharica), glossy buckthorn (R. frangula), and various bush honeysuck- les (Lonicera maackii, L. morrowii, L. tatarica) can be serious problems (Heidorn 1991). Black locust (Robinia pseudoacacia) is a problem in the sand prairies of central Illinois. Another troublesome species in some sand prairies is sour dock (Rumex acetosella). Most plant species that invade and encroach upon hill prairies are native woody species, although black locust is invasive on some hill prairies. The second category of non-native species includes widespread but benign species that occur with regular- ity in prairies. They appear to be adapted to current climate and management practices, are not overly aggressive, and are not likely to dramatically change species composition in the prairies. There are numer- ous examples of these in blacksoil prairies, including Queen-Anne’s-lace (Daucus carota), wild parsnip (Pastinaca sativa) (Kennay and Fell 1992), asparagus (Asparagus officinalis), ox-eye daisy (Chrysanthemum leucanthemum), and moneywort (Lysimachia nummularia). Blackberry-lily (Belamcanda chinensis) is in this category on hill prairies. Kentucky blue grass (Poa pratensis) and Canada blue grass (P. compressa) occur widely in many types of prairies. They are cool- season grasses and begin to grow before most of the native species break dormancy. Although these are a serious problem in some prairies, they do not generally seem to be as extremely disruptive as species in the first category, and they appear impossible to eliminate from prairies; mid-spring burns may, however, help reduce the frequency of occurrence. The third category includes species that will probably be eliminated with proper management practices. These are species that either persist from cultivation or are opportunistic in disturbances in the prairies. Examples include flowering almond (Prunus glandulosa), lily-of-the-valley (Convallaria majallis), cultivated iris (ris species), chicory (Cichorium intybus), and Adam’s needle (Yucca filamentosa). EXAMPLE OF HILL PRAIRIES Hill prairies are situated atop bluffs of the Mississippi River Basin from around St. Paul, Minnesota, to the southern tip of Illinois; extensive hill prairies also occur along the Missouri River in western lowa (Novacek 1985, Novacek et al. 1985). Within Illinois, they occur along the Mississippi River, the Illinois River from its junction with the Mississippi River to Putnam County, and along the Sangamon River in Menard and Mason counties (Evers 1955, Kilburn and Warren 1963) (Figure 18). Most of the hill prairies in Illinois are loess hill prairies (Table 1). Glacial drift hill prairies occur in Coles and Vermilion counties of east- central Illinois (Reeves et al. 1978, Ebinger 1981). Before European settlement, it is likely that hill prairies never formed large continuous segments in Illinois but were fragmented by ravines that dissect the river bluffs and slopes and delimited on the upland sides by forest. Hill prairies typically occupy southwest-facing portions of steep slopes where some combination of hot summer sun, dry prevailing winds, and periodic fire preclude forest vegetation (Evers 1955, Ranft and Kilburn 1969, Bland and Kilburn 1966, Reeves et al. 1978). The flora of these insularized xeric habitats is a combination of typical prairie species, species disjunct from the western plains region, and hill prairie endemics. The most common species are little bluestem (Schizachyrium scoparium), side oats grama (Bouteloua curtipendula), and daisy fleabane (Erigeron strigosus) (Anderson 1972, Kilburn and Ford 1963). In the survey of nine hill prairies discussed below, researchers found little bluestem and side oats grama to be by far the most frequent in occurrence (Table 6), and 22 species were found in more than 10% of the meter-square plots. Because of their relative inaccessibility, typical agricultural activities such as tillage have not been prevalent in these habitats. During field work for the Illinois Natural Areas Inventory of 1976-1977, 446 hill prairies were examined, many less than | acre; only 127 were relatively undisturbed by grazing by domestic livestock (N¥boer 1981). Nevertheless, hill prairies remain as some of the last living windows into the ecology of the prairie biome that dominated Illinois for 8,000 years prior to European settlement. PRAIRIES Table 6. Most common plant species in nine Illinois hill prairies. Column A = percentage of meter-square plots in which the species was found; Column B = average percentage of each plot that was covered by the species. TTT bee US rs Species A B Schizachyrium scoparium 64.6 30.49 { Bouteloua curtipendula 62.4 13.50 adie® Andropogon gerardii 27.5 25.90 Ar tae: ad Dicanthelium spp. 29.8 2.68 Aster azureus 29.2 S29 { ba ete iantes Psoralea tenuiflora 27.5 12.24 — aren, Petalostemum purpureum Sill 3.41 % — Ruellia humilis 12.9 0.96 as Cornus drummondii 152 14.38 Juniperus virginiana Le: 20.60 Solidago nemoralis PEMD 3.14 Senecio plattensis 16.3 0.37 Melilotus alba 18.0 9.05 Rhus glabra [57 27.60 Ambrosia artemisiifolia 14.6 12.55 Eupatorium altissimum SKS) 2.74 Aster ericoides 16.3 9.81 Euphorbia corollata WS 972 1.47 Kuhnia eupatorioides 10.7 2.57 Asclepias verticillata 10.7 Dale Aster patens 12.9 2.47 Cassia fasciculata 14.0 4.48 Figure 18. Locations of natural areas with hill prairie components in Illinois (Source: Illinois Natural Areas Inventory). The Illinois Natural Areas Inventory has identified 90 sites containing about 400 acres of grade A and B hill prairies (Figures 6, 19). Reports suggest, however, that these remaining sites are being lost at an alarming rate (White 1978, Werner in press). In a study of hill prairies in Pere Marquette State Park in Jersey County, McClain (1983) compared aerial photographs of the Acres area taken in 1937 and 1974. It was found that the hill an i ae oe : 323 § prairies were reduced in size by 61.9% in the 37-year = 2 3 g 3 6 ae interval. This decrease was due to the invasion of the Ys e hill prairies by woody plants. Figure 19. Number of acres of grade A and B prairies of various types in Illinois in 1992 (Source: Illinois Natural Areas Inventory). To address the issue of the loss of hill prairie, Natural History Survey staff investigated the rate of loss in area of extant hill prairies during the past 50 years. To do this, researchers used aerial photos from 1940 to the PRAIRIES present. They digitized the aerial extent of nine hill prairies in Illinois. The results suggest that hill prairies have, on average, been halved in acreage since 1940 (Figure 20). This estimate does not include sites that are no longer hill prairies and is thus a conservative estimate of the total rate of habitat loss. Eight of the nine study sites are quite small, covering from | to about 7 acres; only Revis is fairly large. The data show that Revis has decreased in size from 39.16 acres in 1939 to 17.37 in 1988 (Figure 20). In addition to losing significant area, hill prairies are becoming more fragmented as previously continuous areas are divided by woody invasion, especially in small ravines traversing the hill prairies. Much of this loss of hill prairie is from woody invasion around the borders of sites, especially by red cedar, smooth sumac, and rough-leaved and flowering dogwoods. The perimeter-to-area ratio (P/A) is used to estimate the susceptibility of habitat patches to coloni- zation from adjacent habitats. During the 50-year interval encompassed in the recent Natural History Survey study, the average P/A ratio increased by over 100% (Figure 21). Thus, not only are our hill prairies declining from woody invasion at an alarming rate, but the propensity for this woody invasion is accelerating. This phenomenon is illustrated by the observation that sites with a high P/A ratio tend to loose larger propor- tions of their areas during the study period (Figure 22). It is thought that, under present climate conditions, hill prairies will suceed to forest in the absence of fire (Kilburn and Warren 1963, McClain 1983, Schwegman and McClain 1985). A concomitant study of the bio- logical diversity of sites shows that sites that maintain more of their original area during the study period tend to be more diverse in terms of plant species (Figure 23). The results of this study point to a single clear trend— namely, the loss of this rare habitat within Illinois. The Illinois Department of Conservation is currently taking measures to protect some hill prairie sites through active fire management (J. Schwegman and W. McClain, personal communication). There is much debate on the natural fire frequency for hill prairies; estimates range from | to 30 years. When combating advanced recruitment of woody invaders, managed fire frequencies may need to exceed natural levels until woody invasion is suppressed. Even under a fire management program, woody invaders may need to be removed through cutting to restore hill prairie habitats. 20 1.2 i) a 1.0 —— Clendenny G — 99.99% loss of natural grassland habitats. Drainage With drainage of agricultural lands, native grasslands systems have dried out. Nitrogenous pollutants Fertilization increases ability of non-native species to invade and increases the probability of local species loss. Fragmentation Increases probability of local extinctions as a result of small population phenomena. Increases probability of further habitat degradation and species loss. Climate change May result in loss of local diversity, or shifts in relative abundance of species. Fire suppression Increases invasion of woody species. Shifts in relative abundance of species. Non-native species Sometimes can displace native flora and fauna. Extirpation of bison These large herbivores have been lost on Illinois grasslands and cannot be replaced under current habitat abundances and patch sizes. Domestic livestock Facilitate invasion by non-native grasses. Loss of biodiversity. Conservation organizations have taken three different approaches to managing lands to maintain biological diversity (Figure 24). The traditional approach has been to manage lands for particular species of interest to humans (Figure 24, Path A). Prior to the 1970s this typically meant managing for game species such as deer, pheasant, and waterfowl. This emphasis has shifted to include endangered and threatened species. Conservation organizations propose that we should be managing to maximize the diversity of naturally occurring flora and fauna (Figure 24, Path B). This argument has been used to debate the issue of the appropriate frequency of managed fire in grasslands. In particular, fire management with respect to plant diversity versus insect diversity may differ (Stannard 1984). The third approach is to mimic historical abiotic conditions (such as fire) and restore these functions of the environment (Figure 24, Path C). These management philosophies suggest that the different strategies vary in their abilities to drive systems back toward their pristine state (Figure 24). The facts are, however, that we cannot actually measure what the pristine environment should be, much less how to get there. Thus, we are left with a management decision on which pathway to follow. One might argue that this is contextual and depends on which types of ecosystems one is trying to conserve. Pristine Habitat Drainage xotic Species Fire Suppresion Domestic Livestock ; Reinstate Anthropomorphic Changes Natural y Phenomena 7 i a Disturbed Se, Habitat ie ‘ Maximize ~ B Biodiversity N Preserve \ Endangered \ A Species Figure 24. Strategies for natural lands management. The goal of management is typically to restore the land to a pristine, presettlement state. This goal can be achieved by (A) preserving species on a case-by-case basis, (B) using any and all management tools to maximize native biological diversity, and (C) restoring natural processes to mimic presettlement conditions. All three pathways are often assumed to lead to the same goal, and to work in unison with one another, but they may quite often violate this assumption. Within large habitat patches we can actually try to maintain ecosystem functions. Thus, we can effectively pursue a management strategy that reintroduces many of the naturally occurring disturbances to grassland systems (such as bison and fire), while other ecosys- tem-level functions such as drainage have not been as severely disrupted (Figure 24, Path C). For the majority of smaller preserves managers have typically adopted a strategy to use whatever manage- ment tools achieve an appropriate community composi- tion (Figure 24, Path B). Interest in maintaining global biodiversity, as well as state and federal legislation, requires us to apply a species-level management strategy (Figure 24, Path A) at sites where rare and endangered species currently reside. One hopes that paths A, B and C are not mutually exclusive, and that pursuing them suggests similar management actions, all leading toward a pristine environment. In many cases this may be true. In the interest of applying appropriate management strategies, however, we must recognize that these varying objectives may, in fact, result in different activities. A clear recognition of this will help clarify the goals outlined in the subsequent material on stressors to the grassland environment. Destruction of Habitat The single most important stress affecting the remain- ing prairies of Illinois is human exploitation. Conse- quently, the primary management strategy for the preservation/restoration of the remaining prairie remnants is a no loss policy combined with a vigorous restoration program. Currently only 6% of the areas listed on the Illinois Natural Areas Inventory are afforded the maximum protection against future changes in land use as dedicated Illinois Nature Preserves. Seventy-eight percent of Illinois prairie areas are classified as unprotected. The threats of destruction to these unprotected areas are numerous and include building and highway construc- tion, railroad maintenance, grazing, and cemetery mowing. Seventy-three percent of these prairie areas are likely to experience major threats within five years, and 9% are in immediate danger (White 1978). Drainage Most of the land that was originally in mesic to wet blacksoil prairie has been drained as part of the conversion of the land for agriculture. As a conse- quence, the moisture regimes have changed for the small isolated prairie remnants because they are now surrounded by fields. Little can be done in this situa- tion because the adjacent property owners do not want to discontinue drainage. Nitrogen Pollution Most prairie ecosystems are nitrogen limited (Wedin and Tilman 1992). Dominant tallgrass prairie grasses are very efficient consumers of nitrogen from the soil and deplete this resource. In general, sites that are seasonally nutrient limited support a higher diversity of plants than those supplied with ample nutrients. The reason is that fertilization alters the competitive balance between species and allows a few species to dominate at the expense of many others (Tilman 1987, Tilman and Wedlin 1991). The floristic diversity of native prairie at least in part depends upon this nitrogen depletion by the dominant PRAIRIES __ 24 PRAIRIES warm-season grasses. In experimental tests, Wedin and Tilman (1992) found that native prairie grasses successfully outcompete and exclude introduced pasture grasses under low nitrogen conditions, whereas these weedy pests persist with nitrogen fertilization. Thus, seasonal depletion of soil nitrogen, it appears, is an integral part of the functioning of a healthy prairie ecosystem. Nitrogen pollution has dramatically increased during the middle portion of the 20th century as a result of agrichemical fertilization. Runoff and groundflow of these fertilizers may have localized effects on plant community composition in native prairie. Aerial deposition of nitrogen has also increased in Illinois. This presents the problem that nitrogen fertilization of prairie soils may be occurring even in fairly large and pristine grassland habitats and threatens their ability to conserve biological diversity. Fragmentation The potential impacts of fragmentation have been discussed previously in the sections titled “Example of Hill Prairies” and “Concern about Genetic Diversity in Prairie Plants.” Climate Change Very few studies addressing the biological ramifica- tions of global climate change have specifically addressed the potential changes in grassland ecosys- tems. The general predictions of climate change for Illinois include a 2—5°C increase in mean annual temperature, most of which will take the form of warmer winters. In addition, decreased growing season precipitation, resulting in lower soil moisture levels, is also predicted. Under natural conditions, these changes would be predicted to result in an expansion of grasslands (Holeridge 1964, Emanuel et al. 1985). Under current land-use conditions, it seems unlikely that there will be a dramatic shift in prairie versus forested regions within Illinois given that the difference seems to be largely controlled by fire regimes and underlying soils. Perhaps the best prediction that can be made at this time is that prairie habitats on poor soils may experience a decreased propensity for woody species invasion if, in fact, the climate becomes warmer and drier. A potentially dramatic influence of climate change on prairie systems may come from the direct effect of increased atmospheric levels of CO, on prairie plants. Increased levels of CO,, the primary atmospheric gas responsible for driving climatic change, affects the ways in which plants respond to their environment. A growing body of evidence suggests that an increase in CO, levels increases drought tolerance in many species (Farquhar and Sharkey 1982). This increased drought tolerance is important in prairie systems given that the differential response of species to water stress plays a large role in plant community dynamics. One way in which this has been illustrated is how increases in CO, differentially affect warm- and cool-season grasses (Bazzaz and Carlson 1984, Mooney et al. 1991, Melillo et al. 1990). Experiments are under way to determine whether these factors will shift the competitive balance between these species (e.g., Owensby et al. 1993). Finally, climatic parameters often predict the distribu- tions of species (Holeridge 1964, Davis 1988). This information has been used to suggest that changes in climate will alter the natural ranges of species (Davis 1988, Davis and Zabinski 1992). This is viewed as a problem in cases in which the current range does not overlap with predictions of the location of a range under modified climate (Figure 25). The net result could be a loss in biodiversity if migration of these species does not keep pace with climate change. With respect to Illinois prairie plants, however, this extinc- Species Distribution Xe fs Distribution / | Figure 25. Hypothetical species distribution before climate change (A) and after climate change (B) in relation to climatic range (shaded area) of the species. Climatic warming may cause a species to disappear by displacing its range wholly outside the distribution of its climatic tolerance. tion phenomenon is not likely to pose a serious threat. Situated along the eastern edge of the prairie, and with predictions of dry prairie-supporting conditions becoming more prevalent in Illinois, we are likely to experience an increased number of species that would be able to persist in Illinois prairies. The highly fragmented nature of prairies and low habitat availabil- ity make it unlikely that these species will actually be able to migrate into Illinois. The major area in which climate change may affect local diversity of prairie plants would be in the net loss of wet habitat area as conditions become more dry. With respect to animal diversity on prairies, there is no clear prediction that can be made with respect to climate change. Fire Suppression The tallgrass prairie of Illinois is considered a fire- adapted community (Henderson 1982). Historical records indicate that the prairies of Illinois burned frequently (McClain 1992). Considering this fact, it is not surprising that prescribed fire is the most important tool in the development, maintenance, and manage- ment of prairies. Fire can be employed for two purposes in prairie management. In new restorations or neglected rem- nants, fire is used to directly suppress or kill non- prairie species. When fire serves this function, it is important to time the burn such that it coincides with the most vulnerable period in the target species life history (Illinois Nature Preserves Commission 1990). In a healthy system, fire is used to reduce accumulated litter and warm the soil, allowing the prairie plants to gain a competitive edge on their non-native competi- tors (Schramm 1990). Fires that serve this purpose are usually started in the early spring (although there is a trend toward more fall burning; see below). When used properly, fire is very effective at controlling non-prairie species and is the preferred method. However, in cases in which fire is ineffective (purple loosestrife, autumn olive, wild parsnip, black locust, roadside prairies), managers need to employ methods that selectively remove undesirable vegetation. In our smaller preserves we are most often managing grasslands to prevent further habitat loss through non- native and woody species invasion. The major tool used to accomplish these goals is fire. The predominant management goal has been to maintain diversity (Figure 24, Path B) by imposing fire regimes close to what probably occurred naturally (Figure 24, Path C). A better management strategy would be to recognize PRAIRIES ___ maintenance of biodiversity as the goal and determine what fire management strategy this suggests. Scientists have recently renewed the debate regarding the role of fire in maintaining grasslands. Although it is generally recognized that fire is essential for limiting the amount of woody growth on grassland habitats, some research- ers have argued that fire can severely limit the diversity of insect fauna on small preserves. The argument for this goes as follows. If prairies were once extensive and generally wet in Illinois, the natural fire regime probably resulted in a patchy distribution of areas that remained unburned in any given fire event. These unburned patches, then, allow recolonization of burned areas by many insect species purported to be sensitive to fire. Current prairie patches, however, may be too small to allow persistence of populations of sensitive species (Stannard 1984). Several pieces of information suggest that the impact of fire on potentially sensitive insect species is not as great as many suggest. First, there is the fact that most species described in northern Illinois during the early part of this century (during a period of fire suppression) have recently been found (Figure 14); if some subset of these species were very sensitive to fire, we would have lost more species. Second, recent information on an experiment measuring survival and recovery of a wingless prairie leafhopper (proposed as potentially very sensitive to fire) suggests that popula- tions of this species begin to approach pre-burn densities during the first growing season following fire (Panzer, Stillwaugh, and Schwartz, unpublished data; Figure 26). These results suggest that even insect species whose life-history characteristics suggest a sensitivity to fire are able to survive current fire management regimes. Much additional work is needed in this area. 40 —@Oe—_—s unburned —O— burned Number Caught 8 te) 20 40 60 80 100 120 Days after 1 June Figure 26. Densities of Aflexia rubranura in sweep samples of burned and unburned areas of Goose Lake Prairie during summer 1992. 25 26 —_____ PRAIRIES Non-native Species Impacts of non-native plant and animal species have been discussed previously. Most non-native species are here to stay, and little presently can be done to signifi- cantly reduce their frequency of occurrence in prairies. There are certain species that drastically alter the natural community structure, however, and manage- ment efforts should be directed toward these species. Diligent efforts are needed to contain and/or eradicate any newly introduced non-native species that have the potential to become serious problems. Controlling exotics through biocontrol agents may provide a cost- effective method for preserving the integrity of native habitats. Unfortunately, research directed toward development of biocontrol agents is restricted toward exotic species with a direct economic impact. Extirpation of Bison Large herbivores, such as bison, were formerly a strong ecological force affecting grassland habitats; more than 50 million bison roamed the prairies before settlement by Europeans. The vast majority of our now restricted habitat islands are, however, far too small to support even a single bison. Replacing this large grazer with others such as cattle is not an appropriate solution since their diets can be quite different. Likewise, the recent surge in deer populations (see chapter on forest) is affecting community dynamics in grassland systems where they were not before, causing concern among land managers. Domestic Livestock The grazing habits of domestic livestock are quite different from those of bison. Extensive grazing by non-native herbivores changes species frequency occurrence of native plant species and seems to also allow for the introduction and establishment of weedy plant species. Although there have been trials in other states to use cattle on native prairies to simulate grazing by bison, this technique is, at best, suited to prairie areas to the west of Illinois. PRAIRIE MANAGEMENT Current Practices The primary management goals for prairie remnants are to increase species productivity and diversity and to reduce the encroachment of aggressive woody and non- native vegetation. In general, these goals are accom- plished by three management practices: (1) prescribed burning, (2) selective removal of woody or non-native ground cover species, and (3) introduction of native ground layer species (discussed in the prairie restora- tion section to follow). Mechanical control techniques such as mowing, girdling, cutting, and hand-pulling are a viable alternative to fire. Hand-pulling is recommended for purple loos- estrife, autumn olive, Canada thistle, teasel, and wild parsnip (Illinois Natural Preserves Commission 1990). The spot application of herbicides has been found to control several woody species on prairie sites (Illinois Nature Preserves Commission 1990). Herbicides used in conjunction with fire or mechanical measures are very effective in controlling undesirable plant species. For example, fall fire facilitates the control of Melilotus alba by inducing rapid early sprout growth, thereby allowing the application of a herbicide prior to the emergence of the other forbs (Schwegman and McClain 1985, Cole 1991). It is important to remember that, regardless of the short-term control methods used to regulate non-native plant populations, the long-term goal of prairie management should be toward the restoration of the natural processes (fire, hydrology, etc.) that originally maintained the health of the system. Without this goal in mind managers are treating the symptoms and not the disease. Suggested Changes in Management Practice The two most needed changes in Illinois prairie management strategies are in the frequency and timing of fire. In Illinois, fire is not used enough in prairie management (Schramm, Wilhelm, Packard, personal communications). This is surprising considering the importance and cost effectiveness of this management tool. New prairie restorations or neglected prairie remnants should be burnt yearly for up to a decade. Once a mature healthy system is established, the prairie plants will prevent most of the encroachment of undesirable species. At this stage fire should be applied on a rotation of 1-3 years. A conservative manager may wish to burn half of the area each year, providing unburned refugia for insects (Schramm 1990). Changing the timing of the prescribed burn is also being considered in Illinois prairie management. In the past, prescribed burns have usually been conducted in the early spring, but most historical accounts of prairie fires in Illinois indicate that presettlement burning frequently occurred in the fall (McClain 1992). Proponents argue that fall fires burn hotter and will carry over a larger area, while opponents say early spring fires are important for preserving winter wildlife cover and protecting against soil erosion. Both sides, however, agree that fire in either the fall or the spring is better than no fire at all. For more information on fall versus spring burning, see Whisenant and Uresk (1989), Henderson (1990), and Schramm (1990). Prairie Restoration Habitat restoration has been heralded as a viable technique for the amelioration of habitat loss through development. Several prairie restorations have been successful in establishing high biological, or at least botanical, diversity on formerly agricultural or de- graded land. A good example is the Schulenberg Prairie at the Morton Arboretum in Lisle. Initially, volunteers were used extensively to grow plants from seed in a greenhouse, hand-plant the material on the site, and control non-native species. Some direct seeding has been done on additional parts of the site, and there has been considerable species enrichment through transplanting. Another diverse restoration is the Doris L. Westfall Prairie in Forest Glen Preserve (Campbell and Westfall 1991). Over 120 species of prairie plants native to Vermilion County are found in this site, and most have been introduced through repeated seeding. Most prairie restorations, however, contain at most one-fourth to one-half of the plant species that would be found in a natural prairie remnant of comparable size. Several factors are responsible. Because of cost and labor limitations, most prairie restorations are planted with a one-time seeding. Relatively few species are included in the seeding mixes, a number of species included in the mixes rarely succeed from seed, and follow-up species enrichment does not take place. For example, very good records have been kept of the diversity of various restoration projects begun at Fermilab in DuPage County, Illinois. Tracts at Fermilab that have been under prairie restoration management for over 10 years only show a fraction of the floristic diversity of the native prairie. Likewise, the insect diversity on these restorations tends to be uniformly low (Panzer, personal communication). The success of prairie restorations seems to depend largely upon the techniques used to restore the prairie (McClain 1986). Restorations can be conducted through a process of seeding, planting seedlings, or transferring sod from intact prairie. It appears that PRAIRIES ___ transplanting sod increases the likelihood of success in establishing soil microorganisms and a fuller comple- ment of vascular flora. The lack of a full diversity of prairie plants, however, should not discourage the use of restoration techniques to increase the total area of prairie within Illinois. At present, we do not yet know whether these restored sites will eventually become more diverse. Also, over the short term these restora- tion sites provide habitat for species that are becoming increasingly rare in the state. HIGHWAY CORRIDORS With funding from the Illinois Environmental Protec- tion Fund Commission, the Natural History Survey is investigating ways that the extensive Illinois highway corridor system can provide habit for the species that constitute the rich native biodiversity of Illinois. This project is called Corridors for Tomorrow. The Illinois Interstate highway system is the third largest in the nation, with about 1,900 miles of corridors, 370 interchanges, and 31 open or proposed rest areas. Associated with this system is about 135,000 acres of land. These corridors are in state ownership and are subject to far less pressure from economic and owner- ship changes than most land in the state. Following traditional highway management practices, most right-of-way is currently planted with species not native to Illinois or even the United States. Manage- ment practices have also emphasized cyclic patterns of disturbance, such as herbicide use and mowing. As economic restrictions have recently limited this management, and to reflect the public’s growing awareness with the environment, we must reevaluate approaches to roadside design. One alternative is to use highway rights-of-way to provide much-needed habitat for the plants, birds, mammals, and insects that are part of our state’s natural heritage. Each unit in the Interstate highway system—corridors, interchanges, and rest areas—provides opportunities for the effective use of these native plant communities. The long expanses of corridors can be used for prairie grasses, more complete prairie reconstructions, designed interpretations of prairie, mass plantings of native shrubs, and scattered, clustered, or dense stands of native trees. Interchanges present excellent opportu- nities for the use of native plants because of their relative isolation and large size. The extensive space at interchanges will allow better development of prairies, mixed shrubs and trees, simulated woodlands, and savannas. These added habitats offer our native plants 27 28 PRAIRIES and animals structural cover, reproductive sites, and food resources. Revegetation will increase the average size of our habitat fragments and decrease habitat isolation by providing connecting corridors. The importance of highways as dispersal routes connecting habitat fragments has been demonstrated for small mammals. Prairie plantings would also provide habitat for many grassland birds, wintering ground for upland gamebirds and a seed source for migrating birds, and pollen, nectar and food resources for native bees, wasps, butterflies, and other insects. The overall design of highway plantings needs careful consideration to include species that cover the complete range of flowering period, from early spring to late fall, with a broad fruiting period. Plants are largely dependent on insects for pollination and on a wide variety of animals for seed dispersal. A phenologically complete habitat provides optimum conditions for the greatest diversity of native insects, birds, and small mammals. Landscape designs are being developed to provide better interpretations of biodiversity to the motorist than would strict re-creation of native habitats. For example, a realistic prairie restoration 30 feet wide is not very dramatic at 65 miles per hour. A way to help interpret the prairie for the motorist is to dissect it and show the component parts on a large scale. The components could be presented in mass plantings of showy species at intervals along the corridors. This presentation would provide an attractive public educational opportunity. Perhaps the most practical human benefit from reveg- etation efforts in Illinois will be the improvement of the quality of our environment. We are all concerned about how human activities are modifying the very nature of our world. Climatic changes, toxic pollution, erosion, diminishing water quality, food shortage, and depletion of our non-renewable energy resources affect everyone’s life. Diverse highway corridors act as buffers between agricultural and urban development and the existing native habitats of Illinois. These revegetation buffers soak up pollution, capture and store carbon dioxide, filter and dilute dust and exhaust pollution, retard erosion and loss of top soil, and retard siltation of our streams, rivers, and lakes. Reduction of maintenance practices, including mowing and herbi- cide application, will significantly reduce our state’s use of energy and toxic chemicals. Highway landscap- ing with native species also contributes to the scenic beauty of Illinois and leaves motorists with a favorable image. An Illinois revegetation program will also help activate local interest in environmental issues and stimulate grassroot efforts for an environmentally sound Illinois. LITERATURE CITED Anderson, R.C. 1970. Prairies in the prairie state. Transactions of the Illinois State Academy of Science 63:214-221. Anderson, R.C. 1972. Prairie history, management, and restoration. Pages 15-21 in J. Zimmerman, ed. Proceedings of the Second Midwestern Prairie Conference, Madison, Wisconsin. Anderson, R.C. 1982. An evolutionary model summa- rizing the roles of fire, climate, and grazing animals in the origin and maintenance of grass- lands: an end paper. Pages 297-308 in J.R. Estes, R.J. Tyrl, and J.N. Brunken, eds. Grasses and grasslands: systematics and ecology, University of Oklahoma Press, Norman. Anderson, R.C. 1991. Illinois prairies: a historical perspective. Pages 384-391 in L.M. Page and M.R. Jeffords, eds. Our living heritage: the biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4). Axelrod, D.I. 1985. Rise of the grassland biome, Central North America. Botanical Review 51: 163-201. Barrett, C.H., and J.R. Kohn. 1991. Genetic and evolutionary consequences of small population size in plants: implications for conservation. Pages 3-30 in D.A. Falk and K.E. Holsinger, eds. Genetics and conservation of rare plants. Oxford University Press, New York. Bazzaz, F.A., and R.W. Carlson. 1984. The response of plants to elevated CO,. I. Competition among an assemblage of annuals at different levels of soil moisture. Oecologia 62:196—198. Betz, R.F., and H.F. Lamp. 1989. Species composition of old settler silt-loam cemetery prairies. Pages 33-39 in T.B. Bragg and J. Stubbendieck, eds. Proceedings of the Eleventh North American Prairie Conference. Prairie Pioneers: Ecology, History and Culture. University of Nebraska Printing, Lincoln. Betz, R.F., and H.F. Lamp. 1992. Species composition of old settler savanna and sand prairie cemeteries in northern Illinois and northwestern Indiana. Pages 39-87 in D.A. Smith and C.A. Jacobs, eds. Proceedings of the Twelfth North American Prairie Conference, University of Northern Iowa, Cedar Falls. Bland, M.K., and P.D. Kilburn. 1966. Bluff prairie vegetation and soil texture. Transactions of the Illinois State Academy of Science 59:25-28. Bogue, A.G. 1968. From prairie to cornbelt. Farming on the Illinois and Iowa prairies in the nineteenth century. University of Chicago Press, Chicago. 310 p. Bohlen, H.D., and W. Zimmerman. 1989. The birds of Illinois. Indiana University Press, Bloomington and Indianapolis. xvii + 221 p. + plates. Bowles, M., K. Kerr, R. Thom, and D. Birkenholz. 1980. Threatened, endangered and exirpated birds of Illinois. Audubon Bulletin 193:2—12. Burton, P. J., K.R. Robertson, L.R. Iverson, and P.G. Risser. 1988. Use of resource partitioning and disturbance regimes in the design and management of restored prairies. Pages 46-88 in E.B. Allen, ed. The reconstruction of disturbed arid lands. An ecological approach. Westview Press, Inc., Boulder, Colorado, for the American Association for the Advancement of Science, Washington, D.C. Campbell, M.F., and D.L. Westfall. 1991. The prairie in Vermilion County. Outdoor Heritage Founda- tion of Vermilion County, Westville, Illinois. 68 p. Chapman, K., M. White, R. Johnson, and Z.M. Wong. 1990. An approach to evaluate long-term survival of the tallgrass prairie ecosystem. The Nature Conservancy, Midwest Regional Office, Minne- apolis, Minnesota. 50 p. Cole, M.A.R. 1991. Vegetation management guideline: white and yellow sween clover [Melilotus alba Desr. and Melilotus officinalis ( L.) Lam.]. Natural Areas Journal 11:213-214. Davis, M.B. 1988. Ecological systems dynamics. Pages 69-106 in Toward an understanding of global change: initial priorities for U.S. contributions to the International Geosphere-Biosphere Program. National Academy Press, Washington, D.C. Davis, M.B., and C. Zabinski. 1992. Changes in geographical range resulting from greenhouse warming: effects on biodiversity in forests. Pages 297-308 in R.L. Peters, ed. Consequences of greenhouse warming to biodiversity. Yale Univer- sity Press, New Haven, Connecticut. Dennis, A., and D.E. Harry. 1988. Role of genetic variation in the preservation, restoration, and management of tallgrass prairies. Illinois Natural History Survey unpublished report based on presentation to Second Central Illinois Prairie Conference, September 25, 1988, Wildlife Prairie Park, Peoria. PRAIRIES Ebinger, J.E. 1981. Vegetation of glacial drift hill prairies in east-central Illinois. Castanea 46:1 15-121. Emanuel, W.R., H.H. Shugart, and M.P. Stevensohn. 1985. Climate change and the broad-scale distribu- tion of terrestrial ecosystem complexes. Climatic Change 7:29-43. Evers, R.A. 1955. Hill prairies of Illinois. Illinois Natural History Survey Bulletin 26:368-446. Farney, D. 1980. Can the tallgrass prairie be saved? National Geographic 157(1):37-61. Farquhar, G.D., and T.D. Sharkey. 1982. Stomatal conductance and photosynthesis. Annual Review of Plant Physiology 33:317-345. Gleason, H.A. 1922. On the relation between species and area. Ecology 3:158-162. Glass, W.D. 1991. Vegetation management guideline: cut-leaved teasel (Dipsacus laciniatus L.) and common teasel (D. sylvestris Huds.). Natural Areas Journal 11:213-214. Glass, W.D. 1992. Vegetation management guideline: white popular (Populus alba L.). Natural Areas Journal 12:39—40. Gould, J.B., and L. Gould. 1991. Illinois exotic weed act. Illinois conservation law. Chapter 5, Sec. 932. Definition 933. Exotic weeds, Sec. 934. Exotic weed control. Illinois Conservation Law, Binghamton, New York. Graber, R.R., and J.W. Graber. 1963. A comparative study of bird populations in Illinois, 1906-1909 and 1956-1958. Illinois Natural History Survey Bulletin 28(3):383-382. Groombridge, B., ed. 1992. Global biodiversity: status of the earth’s living resources. A report compiled by the World Conservation Monitoring Centre. Chapman & Hall, London. [Chapter 21. Grass- lands. Pages 280-292. ] Hamrick, J.L., and M.J. Godt. 1990. Allozyme diver- sity in plant species. Pages 43-63 in A.H.D. Brown, M.T. Clegg, A.L. Kahler, and B.S. Weir, eds. Plant population genetics, breeding, and genetic resources. Sinauer Associates, Sunderland, Massachusetts. Hamrick, J. L., M.J.W. Godt, D.A. Murawski, and M.D. Loveless. 1991. Correlations between species traits and allozyme diversity: Implications for conservation biology. Pages 75-86 in D.A. Falk and K.E. Holsinger, eds. Genetics and conserva- tion of rare plants. Oxford University Press, New York. Harris, L.D. 1984. The fragmented forest. Island biogeography theory and the preservation of biotic 29 PRAIRIES diversity. University of Chicago Press, Chicago and London. xviii + 211 p. Henderson, R.A. 1982. Vegetation — fire ecology of tallgrass prairie. Natural Areas Journal 2(3):17—26. Henderson, R.A. 1990. Ten-year response of a Wiscon- sin prairie remnant to seasonal timing of fire. Pages 121-126 in D.D. Smith and C.A. Jacobs, eds. Proceedings of the Twelfth North American Prairie Conference, University of Northern Iowa, Cedar Falls. Heidorn, R. 1991. Vegetation management guideline: exotic buckthorns common buckthorn (Rhamnus cathartica L.), glossy buckthorn (R. frangula L.) and Dahurian buckthorn (R. davurica Pall.). Nautral Areas Journal 11:216-217. Henry, R.D., and A.R. Scott. 1980. Some aspects of the spontaneous Illinois vascular flora. Transactions of the Illinois State Academy of Science 73:35—40. Herkert, J.R. 1991a. An ecological study of the breeding birds of grassland habitats within Illinois. Ph.D. dissertation, University of Illinois at Urbana/ Champaign. 105 p. Herkert, J.R. 1991b. Prairie birds of Illinois: Population response to two centuries of habitat change. Pages 393-399 in L.M. Page and M.R. Jeffords, eds. Our living heritage: The biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4). Herkert, J.R., ed. 1991. Endangered and threatened species of Illinois: status and distribution. Volume 1—Plants. Illinois Endangered Species Protection Board, Springfield. iii + 159 p. Herre, A.W. 1940. An early American prairie. Ameri- can Botanist 46:39-44. Hoffmeister, D.F. 1989. Mammals of Illinois. Univer- sity of Illinois Press, Urbana and Chicago. xvii + 348 p. + 16 plates. Holeridge, L.R. 1964. Life zone ecology. Tropical Science Center, San Jose, Costa Rica. Huenneke, L.F. 1991. Ecological implications of genetic vatiation in plant populations. Pages 31-44 in D.A. Falk and K.E. Holsinger, eds. Genetics and conservation of rare plants. Oxford University Press, New York. Illinois Agricultural Statistics Service 1988, 1989. Illinois Endangered Species Protection Board. 1990. Checklist of endangered and threatened animals and plants of Illinois. Illinois Endangered Species Protection Board, Springfield. ii + 26 p. Illinois Nature Preserves Commission. 1990. Vegeta- tion management manual. Vol. 1, No. 1-27. Springfield, Illinois. 134 p. 30 Iverson, L.R. 1988. Land-use changes in Illinois USA: the influence of landscape attributes on current and historic landuse. Landscape Ecology 2:45-61. Iverson, L.R. 1989. Forest resources of Illinois: An atlas and analysis of spatial and temporal trends. Illinois Natural History Survey Special Publication No. 11. Illinois Natural History Survey, Champaign. vii + 181 p. Iverson, L.R. 1992. Illinois Plant Information Network (ILPIN). A data base on the ecology, biology, distribution, taxonomy, and literature of the 3,200 plant species found in Illinois. Illinois Natural History Survey, Champaign. Iverson, L.R., and P.G. Risser. 1987. Analyzing long- term changes in vegetation with geographic information system and remotely sensed data. Advances in Space Research 7:183—194 Kendeigh, S.C. 1941. Distribution of upland birds in Illinois. Transactions of the Illinois State Academy of Science 34:225-226. Kennay, J., and G. Fell. 1992. Vegetation management guideline: wild parsnip (Pastinaca sativa L.). Natural Areas Journal 12:42-43. King, J.E. 1981a. The prairies of Illinois. The Living Museum:42-45. King, J.E. 1981b. Late Quaternary vegetational history of Illinois. Ecological Monographs 51:43-62. Kilburn, P.D., and C.D. Ford, Jr. 1963. Frequencies of hill prairie plants. Transactions of the Illinois State Academy of Science 56:94—97. Kilburn, P.D., and D.K. Warren. 1963. Vegetation — soil relationships in hill prairies. Transactions of the Illinois State Academy of Science 56:142—145. Klopatek, J.M., R.J. Olson, C.J. Emerson, and J.L. Joness. 1979. Land-use conflicts with natural vegetation in the United States. Environmental Conservation 6(3):191-199. Loveless, M.D., and J.L. Hamrick. 1984. Ecological determinants of genetic structure in plant popula- tions. Annual Review of Ecology and Systematics 15:66-95. MacArthur, R.H., and E.O. Wilson. 1967. The theory of island biogeography. Princeton University Press, Princeton, New Jersey. xi + 203 p. Madson, J. 1982. Where the sky began: land of the tallgrass prairie. Houghton Mifflin Company, Boston. xii + 321 p. McClain, W.E. 1983. Photodocumentation of the loss of hill prairie within Pere Marquette State Park, Jersey County Illinois. Transactions of the Illinois State Academy of Science 76:343-346. McClain, W.E. 1986. Illinois prairie: past and future, a restoration guide. Illinois Department of Conserva- tion, Springfield. 26 p. McClain, W.E. 1992. The occurrence of prairie fires in Illinois and adjacent midwestern states during the period of 1673 to 1873 (abstract). Illinois Forest Conference, Eastern Illinois University, Charleston. Melillo, J.M., T.V. Callaghan, F.I. Woodward, E. Salati, and S.K. Sinha. 1990. Effects on ecosys- tems. Pages 283-310 in J T. Houghton, G.J. Jenkins, and J.J. Ephraums, eds. Climate change: The IPCC scientific assessment, Cambridge University Press, Cambridge. Menges, E.S. 1991. The application of minimum viable population theory to plants. Pages 45-61 in D.A. Falk and K.E. Holsinger, eds. Genetics and conservation of rare plants. Oxford University Press, New York. Mohlenbrock, R.H. 1983. Where have all the wildflow- ers gone? A region-to-region guide to threatened or endangered U. S. wildflowers. Macmillan Publishing Co., Inc., New York. xiv + 239 p.+4 plates. Mohlenbrock, R.H. 1986. Guide to the vascular flora of Illinois. Revised and enlarged edition. Southern Illinois University Press, Carbondale and Edwardsville. xi + 507 p. Mooney, H.A., B.G. Drake, R.J. Luxmoore, W.C. Oechel, and L.F. Pitelka. 1991. How will terres- trial ecosystems interact with changing CO, concentration of the atmosphere and anticipated climate change? Bioscience 41:96—104. Nelson, E.W. 1876. Birds of northeastern Illinois. Essex Institute Bulletin 8:90-155. Novacek, J.M. 1985. The loess hills of western Iowa: a problem in phytogeography. Proceedings of the Iowa Academy of Science 92:213-219. Novacek, J.M., D.M. Roosa, and W.P. Pasater. 1985. The vegtetation of the loess hills landform along the Missouri River. Proceedings of the Iowa Academy of Science 92:199-212. Nuzzo, V.A. 1986. Extent and status of Midwest oak savanna: presettlement and 1985. Natural Areas Journal 6(2):6—36. Nyboer, R.W. 1981. Grazing as a factor in the decline of Illinois hill prairies. Pages 209-211 in R.L. Stuckey and K.J. Reese, The prairie peninsula—in the “shadow” of Transeau. Proceedings of the Sixth North American Prairie Conference. Ohio Biological Survey Biological Notes 15. Orwig, T.T. 1992. Loess hill prairies as butterfly survivia: opportunities and challenges. Pages 131— PRAIRIES 135 in D.A. Smith and C.A. Jacobs, eds. Proceed- ings of the Twelfth North American Prairie Conference. University of Northern Iowa, Cedar Falls. Owensby, C.E., P.I. Coyne, J.H. Ham, L.M. Auen, and A.K. Knapp. 1993. Biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated CO,. Ecological Applications 3:644-653. Page, L.M. and MLR. Jeffords, eds. 1991. Our living heritage: The biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4):357-377. Panzer, R. 1988. Management of prairie remnants for insect conservation. Natural Areas Journal 8(2): 83-90. Parrish, J.A.D., and F.A. Bazzaz. 1979. Difference in pollination niche relationships in early and late successional plant communities. Ecology 60: 597-610. Post, S L. 1991. Appendix One: Native Illinois species and related bibliography. Pages 463-475 in L.M. Page and M.R. Jeffords, eds. Our living heritage: The biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4). Ranft, C.R., and P.D. Kilburn. 1969. Evapotranspira- tion contrasts between south-facing bluff prairies and north-facing forest. Transactions of the Illinois State Academy of Science 62:85-90. Reed, P.B., Jr. 1988. National list of plant species that occur in wetlands in Illinois. U.S. Fish and Wildlife Service. NERC-88/18.13. Reeves, J.T., U.G. Zimmerman, and J.E. Ebinger. 1978. Microclimatic and soil differences between hill prairies and adjacent forests in east-central Illinois. Transactions of the Illinois State Academy of Science 71:156-164. Ridgway, R. 1889. The ornithology of Illinois. Volume 1. Illinois State Laboratory of Natural History, Bloomington. 520 p. Ridgway, R. 1895. The ornithology of Illinois. Volume 2. Illinois State Laboratory of Natural History, Bloomington. Risser, P.G., E.C. Birney, H.D. Blocker, S.W. May, W.J. Parton, and J.A. Wiens. 1981. The true prairie ecosystem. Hutchinson Ross Publishing Co., Straudsburg, Pennsylvania. xiv + 557 p. Schramm, P. 1990. Prairie restoration: a twenty-five year perspective on establishment and manage- ment. Pages 169-177 in D.A. Smith and C.A. Jacobs, eds. Proceedings of the Twelfth North American Prairie Conference. University of Northern Iowa, Cedar Falls. 31 32 PRAIRIES Schwegman, J. 1973. Comprehensive plan for the Illinois Nature Preserves System. Part 2. The natural divisions of Illinois. Illinois Nature Preserves Commission, Rockford. 32 p. + map. Schwegman, J. 1983. Illinois prairie: then & now. Outdoor Illinois, January 17, pages 3-13. Schwegman, J.E., and W.E. McClain. 1985. Vegetative effects and management implications of a fall prescribed burn on an Illinois hill prairie. Natural Areas Journal 5(3):4-8. Solecki, M.K. 1989. The viability of cut-leaved teasel (Dipsacus laciniatus L.) seed harvested from flowering stems—management implications. Natural Areas Journal 9:102—105. Stannard, L.J. 1984. On the origin and maintenance of La Grande Prairie of Illinois. Erigenia, Journal of the IlInois Native Plant Society 1984:31-36. Swink, F., and G. Wilhelm. 1979. Plants of the Chicago region. Revised and expanded edition with keys. The Morton Arboretum, Lisle, Illinois. Ixxiii + 922 p. Templeton, A.R. 1991. Off-site breeding of animals and implications for plant conservation strategies. Pages 182-194 in D.A. Falk and K.E. Holsinger, eds. Genetics and conservation of rare plants. Oxford University Press, New York. Tilman, D. 1987. Secondary succession and the pattern of plant dominance along experimental nitrogen gradients. Ecological Monographs 57:189-214. Tilman, D., and D.A. Wedin. 1991. Dynamics of nitrogen competition between successional grasses. Ecology 72:1038—1049. Transeau, E.N. 1935. The prairie peninsula. Ecology: 423-437. U.S. Department of Commerce, Bureau of the Census. 1989. Weaver, J.E. 1954. North American prairie. Johnsen Publishing Co., Lincoln, Nebraska. 348 p. Weaver, J.E. 1968. Prairie plants and their environ- ment. A fifty year study in the Midwest. Univer- sity of Nebraska Press, Lincoln. ix + 276 p. Wedin, D.A., and D. Tilman. 1992. Nitrogen cycling, plant competition, and the stability of tallgrass prairie. Pages 5-8 in D.D. Smith and C.A. Jacobs, eds. Proceedings of the Twelth North American Prairie Conference. University of Northern lowa Press, Cedar Falls. Werner, P.A. 1975. The biology of Canadian weeds. 12. Dipsacus sylvestris Huds. Canadian Journal of Plant Science 55:783-794. Werner, W.E., Jr. (In press.) Vegetative dynamics of the forest/prairie interface at Cole Creek Hill Prairie. Proceedings of the Illinois Forest Confer- ence. Erigenia vol. 13. Westemeier, R.L. 1983. Responses and impact by pheasants on prairie-chicken santuaries in Illinois: a synopsis. Pages 117-122 in R.T. Dumke, R.B. Stiehl, and R.B. Kahl, eds. PERDIX III: Gray partridge and ring-necked pheasant workshop. Wisconsin Department of Natural Resources, Madison. Westemeier, R.L. 1990. Prairie-chicken responses to management in Illinois before and aftrer pheasant intervention. Pages 4-6 in Summaries of selected talks from Prairie Chickens at the Crossroads. Missouri Prairie Foundation and Missouri Depart- ment of Conservation. Westemeier, R.L., and W.R. Edwards 1987. Prairie- chickens: survival in the Midwest. Pages 119-131 in H. Kallman, C.P. Agee, W.R. Goforth, and J.P. Linduska, eds. Restoring America’s wildlife. U.S. Fish and Wildlife Service, Washington, D.C. Whisenant, S.G., and D.W. Uresk. 1989. Burning upland, mixed prairie in Badlands National Park. Prairie Naturalist 21(4):221—227. White, J. 1978. Illinois natural areas inventory techni- cal report. Volume 1. Survey methods and results. Illinois Natural Areas Survey, Urbana. xix + 426 p. Widrlechner, M.P. 1989. Germplasm resources information network and ex situ conservation of germplasm. Pages 109-114 in T.B. Bragg and J. Stubbendieck, eds. Proceedings of the Eleventh North American Prairie Conference. Prairie Pioneers: Ecology, History and Culture. University of Nebraska Printing, Lincoln. Zimmerman, J.L. 1971. The territory and its density dependent effect in Spiza americana. Auk 88: 591-612. FORESTS SUMMARY A review of some of the trends apparent in Illinois forests over the past several decades reveals the following conclusions: 1. Total forest area is now increasing statewide due to several incentive and educational programs. The only exception may be in the south-central portion of the state, where fragmentation is apparently continuing. 2. Timber volume increased by 40% between 1962 and 1985. Volumes for most forest types have increased substantially, with the exception of elm-ash-cotton- wood, which has decreased because of Dutch elm disease. Net annual growth, by contrast, was 30% higher in 1962 than in 1985, showing the aging nature (with concomitant slowing of growth rates) of our secondary forests. 3. The composition of the forests is changing dramati- cally. Maple species are replacing much of the oak- hickory forests as well as dominating new forestland succeeding from abandoned pastures. The oak-hickory forests are not being regenerated and will thus continue to decrease in area and importance. 4. Because of the dramatic increases in volume, the Illinois forests served as a large carbon sink from 1962 to 1985. The annual sequestration of carbon into Illinois forests is estimated to be 1.37 million metric tons, enough to counteract about 2.65% of the total carbon emissions being put into the atmosphere by the people of Illinois. 5. Most of the forests are associated with the state’s stream network. In the south-central portion of the state, 78% of the forestland lies within 300 m of the streams. 6. The biological diversity of the state is being carried, in large part, by the forests. Over half of the native flora and over half of the threatened or endangered flora are found in the state’s forests. According to one index, over 75% of the wildlife habitat in the state is found within the forests. 7. The invasion of exotic species is one of the most serious problems facing Illinois forests, and this problem continues to increase both in severity and scope. Exotic plants reduce within-site plant diversity, as well as reducing habitat quality for native fauna. Exotic insect pests and pathogens threaten Illinois populations of several key species of trees. 8. Forest habitat loss and fragmentation have reduced the ability of Illinois forests to maintain biological diversity in numerous ways. The effects of habitat loss and fragmentation include (a) loss of appropriate habitat for species requiring large tracts of forest (e.g., many large mammals and birds); (b) invasion by exotic species, particularly weedy plants, of the forest interior and habitat edges; (c) increases in potentially damaging native species (e.g., deer) that use habitat edges and threaten biological diversity within sites; (d) increased probability of chance extinction of small, isolated populations; and (e) decreased gene flow between isolated populations, increasing the likelihood of inbreeding depression for both flora and fauna. 9. Effects of pollution (NO,, SO,, ozone depletion) and global warming on forest health in Illinois appear minor relative to changes in forest health in the northeastern United States and Europe, where forest decline is severe. Habitat fragmentation, exotic species, and plant diseases, however, are having a negative impact on forest biodiversity in Illinois. Past timber harvest practices may also have had a long-lasting negative impact on forest quality. Although Illinois currently does not have forest decline problems, all of these factors may contribute to decreased forest health in the future. FOREST AREA Historical Changes: 1820-1985 Illinois forests have undergone drastic changes in the decades since European settlement. In 1820, 13.8 million acres of forest existed in the state (Figure 1). Only 31% (4.26 million acres) of the forest area present in 1820 remained in 1980 (Figure 1), and essentially all (except for about 11,600 acres) of the 33 oS FORESTS present forests are considered to be secondary forest. Illinois ranks 49th (Lowa is 50th) in the percentage of land remaining in its original vegetation type (11%) (Klopatek et al. 1979). The pattern and rate of defores- tation in the latter part of the last century rivals, and even surpasses, that of tropical deforestation occurring today. Nonetheless, forest area has recently been increasing in the state. The lowest estimate of forest area in the state was made by Telford (1926), which estimated forest area to be only 3.02 million acres, compared to estimates of 4.0 million acres in 1948 (U.S. Forest Service, 1949), 4.04 million acres in 1962 (Essex and Gansner, 1965, updated by Hahn 1987), and 4.26 million in 1985 (Hahn 1987). Forest area increased by 10% from 1962 through 1985, due primarily to reduced cattle production in the state during that period with subsequent conversion of hayland and pastures to secondary forest. Recent farm programs, such as the Conservation Reserve Program and the Illinois Forestry Development Act, have provided incentive to convert additional, marginal acres to forestland. When the state is evaluated according to five ecologi- cally based regions (Figure 2), the changes in forest area since 1820 show similar patterns: major declines in forest area occurred between 1820 and 1924, with slow increases in area since 1924 (Figure 3). The only region to lose forest area between 1962 and 1985 was the South-Central Region, a group of 31 counties south of the Shelbyville moraine and north of the Shawnee Hills. In this region, Bond, Clark, Clinton, Fayette, Franklin, Gallatin, Hamilton, Jasper, Lawrence, Marion, Montgomery, Perry, Richland, Shelby, St. Clair, Wabash, and Wayne counties each lost more than 5,000 acres of forestland. Counties in other regions losing more than 5,000 acres were Alexander and Massac from the Southern Unglaciated Region, Greene from the Western Region, and Lake from the Northern Region. By contrast, 38 counties gained more than 5,000 acres of forestland during this interim, Figure 1. Forests in Illinois in 1820 (left) and 1980 (right). Sources: Anderson 1970 and U.S. Geological Survey land-use data, 1973-1981. mostly from the northern two-thirds of the state (9 of 12 counties from the Northern Region, 11 of 31 counties from the Grand Prairie Region, 14 of 21 counties from the Western Region, | of 31 counties in the South-Central Region, and 3 of 7 counties in the Southern Unglaciated Region). County-by-county trends in forest area between 1962 and 1985 are shown in Figure 4. Clearly, forest area generally increased in northern counties (especially those along the major river systems), while significant forest losses occurred in the southern portion of the state (with the exception of Shawnee National Forest counties). Forest Pattern and Trends in the South- Central Region To better understand the temporal and spatial patterns of forest patches in the South-Central Region, one 1990 Landsat TM scene, which covered all of 13 counties, was analyzed in detail (Figure 5). This region was selected for intensive study because it was the only region where forest loss occurred from 1962 to 1985. The satellite data were at a resolution of 98 x 98 ft (30 m x 30 m), so that forest patches as small as approxi- mately 0.25 acre (0.1 ha) could be identified . The 16000 1 Southern unglaciated — 12000 South Central 8 EJ Western = Grand Prairie 2 8000 HB Northern 7) 2 — G 04424. V/L/) 0 enna SLLELL Ls 1820 1924 1948 1962 1985 Year Figure 3. Changes in forest area by region, 1820-1985. Figure 2. Illinois regions: (a) Northern, (b) Grand Prairie, (c) Western, (d) South Central, and (e) Southern Unglaciated. Figure 4. Changes in forest area by county (acres X 1000), 1962-1985. FORESTS ———— 35 FORESTS distribution of the forest is highly fragmented, and the forest is primarily located adjacent to streams. Direct comparisons of the 1990 satellite image assess- ment and a 1985 estimate by the U.S. Forest Service (a sampling procedure) are not reliable because the two studies used completely different methodologies. Still, it is useful to estimate forest area and fragmentation amount in this portion of the state. U.S. Forest Service data are summarized as “commercial” forestland, where commercial forestland is defined as all forested habitat that is not publicly held or explicitly withheld from potential timber harvest (state parks and nature preserves); this covers 95% of all forestland in Illinois. The forest area for the 13 counties as determined from the 1990 satellite data was substantially lower than the 1985 or 1962 estimates of the U.S. Forest Service (Figure 6). It is likely, however, that many of the changes can be attributed to variation in the methodol- ogy; the classification of the satellite data did not include some areas that were interpreted by the U.S. 36 Figure 5. Satellite image classification (from 1990) of forests for 13-county region in south-central Illinois, showing that most remaining forest stands are along streams and rivers. Forest Service as forest in 1985. Still, the region of satellite analysis was the one portion of the state that showed a decline in forest area between 1962 and 1985 (Figures 3 and 4), and the decreasing trend might have continued from 1985 to 1990. The satellite data also show the fragmented nature of the forests. Fragmentation of forest habitat generally has negative implications for wildlife, especially for neotropical migrant birds that need large blocks of uninterrupted forest for successful nesting. As large tracts of forest are broken into small, isolated woodlots, more forest edge is created and more opportunities exist for edge-adapted species, most commonly the cowbird, to invade the area and prevent adequate nesting for many forest songbirds. The vast majority of forest parcels in this region are less than 1 acre (0.4 ha) (Figure 7). These small forest patches would be areas (ranging to as small as about 65 x 65 ft, or 20 x 20 m) where trees dominate, even in backyards, so that the 98 x 98 ft (30 x 30 m) pixel would classify as forest in the satellite imagery. Parcels greater than 40 acres (16 ha) are much less common, with the number of parcels of this size in each county ranging from 95 in St. Clair County to 269 in Fayette County. When one considers the larger forest patch sizes that may be needed to support forest interior birds (e.g., 600 acres or 243 ha) , the numbers drop to a range of 3 in Montgomery County to 17 in Fayette County. When evaluated on a per-unit area basis (the density of forest patches per township-sized area of 36 square miles, or 93.2 km?), one can better understand the “population dynamics” of the forest patches. The number of forest patches under 1 acre (0.4 ha) per township-sized area ranged from 211 to 770 in St. Clair and Jefferson counties, respectively. The data also show the paucity of large forest patches in the region. A summation of all patches greater than 40 acres (16 ha) reveals that only 5.2 patches of this size can be found, on average, in each township of St. Clair County, ranging up to 14.1 patches per township in Jefferson County. Jefferson County originally (ca. 1820) was 73% forest, at least 20% higher than any of the other counties in the study area (Iverson et al. 1989); it therefore would be expected to have the highest density of forest patches remaining. For the entire 13-county area, there were an average of 10.1 forest patches per township, only about one patch for each 4 square miles (10 km?). A cautious comparison of these data can be made to data from a different study. Using U.S. Geological Survey land-use data dating from 1974 to 1979, FORESTS =———— Iverson et al. (1989) found that the density of forest patches greater than 40 acres ranged from 7.1 to 9.7 per township in this region. Although the data are not completely comparable, they suggest a slight increase in patch density from the 1970s to 1990. This trend could have occurred in at least two ways: (1) some additional patches of at least 40 acres could have been added to the pool due to regrowth or aggregation of smaller patches, or (2) some quite large patches could have been split into two or more medium-sized (but OO 1962 fA 1985 Wi 1990 Washington ZZ 7 St Clair Goa Shelby bez Montgomery zzz 7 : ————————— Marion Goze : [es Madison 2Z2zZ77aaareaeaea [SE Macoupin LD LD LD LS LE TLE LDV LF WELT MBE LP FP SE Jefferson Bazaar) 3 Se ee SS Faye tte FST LI LF LET LP LD SBE MF EE LE SE LEP EPP LE 8 Eee See Effingham (2777 ZZ —— Clinton Baza SSS ES Clay CLI LT LILI LT LT LE LS LS Bond ) 20 40 60 80 100 Acres (x 1000) Figure 6. Number of acres of forest in 13 counties in south-central Illinois, 1962-1990. >600 100-600 40-100 10-40 Acreage category 1-10 <1 100 1000 10000 1000000 Number of Parcels 100000 Figure 7. Number of forested parcels in 13 counties in south-central Illinois, as detected by satellite in 1990. 37 FORESTS still > 40 acres) patches due to continued fragmenta- tion. Based on the data presented here and a reevalua- tion of the data in Iverson et al. (1989), the latter is most likely the case. By overlaying the forest classification from satellite data with the streams from the area (1:100,000 digital line graph files), we can estimate the proportions of the Illinois forests that lie within certain distances of the streams. For this area, no less than 78% of the forests exist within 984 ft (300 m) of the streams (Figure 8). A full 22% of the forests are found within 98 ft (30 m) of the streams. An evaluation of the distribution of forests circa 1820 (Figure 1) shows that the close proximity of streams and forest in this region has historically been the case; the streams were efficient fire barriers that reduced the frequency of fires. The data also show the massive elimination of upland forests that were deemed more “suitable” for other uses. These data provide at least circumstantial evidence of the importance of forests in maintaining stream health, and the reverse is also true (see Osborne and Wiley 1988). This original research on 13 counties in south-central Illinois can be summarized as follows: (1) in the absence of more frequent U.S. Forest Service invento- ries (which would be very valuable), satellite data can be used to understand the distribution of forestlands across the state (however, calibration and further research is needed in this area); (2) forest area changes in the region are unclear, but forest area is probably not increasing as in the rest of the state; (3) there is extraordinary fragmentation of the forests; and (4) forests occur mainly near streams and rivers. Ownership Patterns of Illinois Forests More than 90% (3.64 million acres) of the commercial forests in Illinois are privately owned, mostly by farmers and other individuals (Figure 9). The remain- ing 10% is publicly owned, primarily by the federal government in the form of the Shawnee National Forest. The Cooperative Extension Service of the U.S. Department of Agriculture estimated that Illinois had 169,073 private forestland owners, each of whom owned an average of 21.5 acres of forest. The primary reasons for forest ownership given by the holders of small parcels were wildlife habitat and aesthetic value (Young et al. 1984); income was of greater importance for those who owned large forest parcels (McCurdy and Mercker 1986). FOREST PLANT DIVERSITY Vascular Plant Diversity The Illinois Plant Information Network (ILPIN) contains habitat and distribution data for the flora of Illinois (Iverson and Ketzner 1988). Using ILPIN, one can asséss the distribution of forest vascular plant species within Illinois. Mapping the number of species of forest plants by county reveals that the areas of highest diversity are the Chicago region, western Illinois, and the very southern tip of Illinois (Figure 10). This geographic distribution corresponds to the general regions of maximum forest cover (Figure 1), but climate and geomorphic variations are also respon- sible for the biogeography of the state. The wide range in latitude from north to south accounts for a consider- able range in climate and geomorphic conditions, and subsequently, a remarkable diversity of habitats. The presence of many species with affinities toward the northern temperate flora results in increased diversity 100 a7) 2 80 WL ie x 60 i) = 40 & é E 20 oO 0 500 1000 1000+ Distance from Stream (ft) Figure 8. Cumulative percentage of forest within various distances from streams in 13 counties in south- central Illinois. _. Government 9.6% (federal 7.2%, state 1.4%, local 1.0%) —Corporate Ownership (6.6%) Ae Individuals 63.4% (farmers - 45.3%, nonfarmers - 38.1%) Figure 9. Ownership of Illinois forests, 1985. in the northern counties, while species characteristic of the Appalachian flora increase diversity in the southern counties (Figure 10). Likewise, plants with affinities toward southern floodplains increase the species diversity along the major waterways in the western counties (Figure 10). This general pattern of regions with high biological diversity is reflected in both wetland and prairie species as well (see corresponding chapters in this report). Over 250 species of trees (native and introduced) have been recorded in Illinois. Southern counties have the greatest variety: Jackson has 145 species, Pope 129, and Union 128; several northeastern counties also have high diversity due to varied landscapes and escaped cultivars from the Chicago region (Figure 10). In addition to the trees, there are 284 taxa of shrubs (some of which can also be called trees) and 47 taxa of lianas reported for the state. Overall, 508 taxa of woody plants have been recorded, including 138 introduced species. Illinois’ forests are exceptionally rich in nonwoody taxa as well. Including the woody species, there are 1,581 forest-associated plant taxa in the state, 1,414 (89%) of which are native. Jackson County—a botanically rich southern county that is also the home of Southern Illinois University, from which numerous botanical surveys have been conducted—has 954 forest-associated native taxa on record, whereas Warren County in the northwest (not close to a botanical center) has had only 262 taxa recorded. In general, higher botanical diversity occurs in the southern counties, with species having affinity to the Appalachian flora, and in the northern counties, with species rich in the northern temperate flora. As one might expect, relatively lower diversities of forest- associated species are naturally found in the counties formerly dominated by prairie. With diversity at its highest in the northern and southern counties, it is not surprising that the highest concentrations of threatened and endangered species, as well as exotic species, occur in the northern and southern counties (Figure 10). One additional pattern is noteworthy among these figures on the distribution of floral diversity in Illinois. There are a great many more non-native species in any given region than there are threatened and endangered species (Figure 10). This observation suggests that the exotic species problem may be bigger than the threatened and endangered species problem with respect to conserving biological diversity within Illinois. Legislative action has assured some level of protection against further losses in native species diversity. The lack of such legislative structure FORESTS regarding exotics gives very little protection from further introductions of exotic species, whether intentional or accidental (see below). Recent Changes in Forest Composition The composition of Illinois forests has changed dramatically over the past three decades. Today, about one-half of the commercial forest acreage is oak- hickory, one-fourth is maple-beech (almost exclusively sugar maple), and one-sixth is elm-ash-soft maple (Figure 11). Together, the remaining forest types (white-red-jack pine, loblolly-shortleaf pine, oak-pine, and oak-gum-cypress) account for an additional 217,000 acres of commercial forestland. In 1962, however, there was much more acreage of oak-hickory and elm-ash-cottonwood and very little area dominated by the maple-beech type. Since 1962, the maples have increased by a factor of 41, whereas the oaks have been reduced 14% and the elms have been cut in half (Figure 11). The loss of oak-hickory forest is largely explained by the “maple take-over,” in which mature oak-hickory forests are unable to regenerate themselves because the tree seedlings are intolerant of excessive shade in the absence of fire. By contrast, maple seedlings thrive in the shady environment and are positioned for rapid growth and dominance once the overstory is removed or dies. The reduction of elm-ash- soft maple is largely due to the effects of Dutch elm disease and the conversion to agriculture of bottomland forests that once supported these trees (especially in the South-Central Region). These trends are also evident by the age class distribu- tion of the major forest types (Figure 12). The oak- hickory type dominates in the older age classes, whereas the maple-beech type dominates in the younger age classes; as time passes, maples will continue to increase in dominance. The age class distributions within forest types have changed between 1962 and 1985. Both the elm-ash-cottonwood and oak- hickory forests have matured during this 23-year period (Figure 13). In contrast, the oak-gum-cypress has shifted from primarily older stands to primarily younger stands (Figure 13). Maple-beech forests, while increasing dramatically in total acreage (Figure 11), have not shifted in the age distribution of stands (Figure 13). This pattern is likely to change in the future as these stands mature. Finally, pine has not shifted its relative distribution between older and younger stands during the 23-year census interval (Figure 13). 39 oS) FORESTS Number of Number of native, forest- tree taxa associated species [-—] 260-399 400-499 PRE] 500-599 600-699 GE 700 Number of non-native forest species Number of T&E species [| Le 20 21-30 SESS] 31-40 41-50 BRE] GT so Figure 10. The total number of forest-assaciated, native species (top left), number of tree taxa (top right), number of threatened and endangered (T & E) species (bottom left), and number of non-native forest species (bottom right) in each Illinois county as recorded by the Illinois Plant Information Network. 40 FORESTS Tree Abundance An estimated 1.93 billion trees stood in Illinois commercial forests in 1985 (Hahn 1987). Surprisingly, the most common tree type was the elm, with 344 million trees (Figure 14). These are not the American elm, however, which was devastated by Dutch elm disease, but the slippery, or red, elm, which rarely attains a large stature but is very common in the understory. Overall, white oaks (99 million), red oaks (136 million), hickories (185 million), hard maples (117 million), and soft maples (91 million) were very abundant. Based on these trends and the dynamics of forest regeneration in the absence of fire, the future will show an increase in maple abundance and concomitant decreases in oak and hickory abundance. Timber Volume, Growth, Harvest, and Mortality The total volume of growing stock in 1985 was 4.8 billion cubic feet, 40% greater than the 3.4 billion cubic feet reported for 1962 (Hahn 1987). Net volume Oak-hickory Maple-beech § Elm-ash-soft maple jj Oak-gum-cypress Osk-pine Loblolly, shortleaf pine } White, red, jack pine t) 1000 2000 3000 Acres (x 1000) Figure 11. Composition of Illinois commercial forests, 1962 and 1985. Sey DO all others 500 133] Elm-Ash-Maple a EB Mople-Beech S 400 WE oook-Hickory Oo — x 300 Het 7) 5 200 < 5 15 25 35 45 SS 65 75 65 95 110 130 150 Age class (in years) Figure 12. Acreage by age class of the major forest types in Illinois, 1985. estimates for 1985 showed the prominence of oak and hickory in commercial forests, with considerable amounts of ash, black walnut, cottonwood, elm, maple, and sycamore as well (Figure 15). The 1985 volumes averaged 47.4 million cubic feet per county or 1,200 cubic feet per acre of commercial forestland in the state. The trends in volume since 1948, by species group, are shown in Figure 16. For all groups except elm, there was a dramatic increase in volume since 1962. The elms have declined since 1948 due to bottomland conversion to agriculture and Dutch elm disease. White and red oaks and black walnut had total volume decreases from 1948 to 1962 (due to a drop in forest- land area because volume per acre increased slightly during the period), but showed increases in volume from 1962 to 1985 (due to a large increase in volume per acre in spite of a decrease in oak area during this period). The other types—hickories, maples, and ashes—have increased in volume since 1948. Net annual growth was estimated in 1985 (Hahn 1987) to be 96 million cubic feet of growing stock or 437 million board feet of sawtimber. Over 42% of net annual sawtimber growth was accounted for by oaks, with another 10% from soft maple, 6.3% from ashes, 3.7% from black cherry, 3.3% from hard maple, and 3.2% from black walnut. Only elm and black ash showed negative growth rates between 1962 and 1985, attributable to Dutch elm disease and the clearing of bottomlands. Compared to the 1985 data, the 1962 inventory showed a 30% higher level of annual growth (125 million cubic feet of growing stock). The lower annual growth and higher volumes in 1985 compared to 1962 indicate that growth has outstripped removals in the past several decades and that growth rates may be declining due to maturing forests (Figure 16). The trends in volume during 1962-1985, when evaluated by county, show large percentage increases for all northern and central counties (except Whiteside) but generally lower or even negative volume changes for south-central counties (Figure 17). This trend can be primarily linked to the area changes for the region as discussed previously (see Figure 4). Illinois ranks fifth in the nation in demand for wood but 32nd in the production of wood. Although we import much of the wood we need from other states, 14% of the wood harvested in Illinois is processed in neighboring states. This processed wood is often then imported back into Illinois. Currently, the annual growth of timber (96 million cubic feet) exceeds timber 41 42 FORESTS removals (68.6 million cubic feet), so that accumula- tion of volume statewide will continue, barring major harvest changes, into the near future. An enormous quantity of firewood—nearly 2 million cords a year—is harvested from Illinois forests. About 43% of the trees used (harvested or salvaged) in a given year in Illinois are used for firewood! The demand for firewood does not currently present a major threat to our forests, however, because 75% of the firewood cut is taken from dead trees. The major harvest of fuelwood takes place in the heavily popu- lated northeastern counties (Figure 18). Trees cut for sawlogs, by contrast, are primarily found in the southern half of the state (Figure 19), with the major counties cutting sawlogs in 1983 being Franklin, Fulton, Jackson, and White (with over 6 million board feet per county). To summarize, biomass and annual harvest have increased statewide during the past 23 years while Elm-Ash-Cottonwood Percent of Total Acreage Percent of Total Acreage Stand Age (Years) annual growth has decreased (Figure 20), possibly as a result of maturing stands (Figure 13). Mortality rates during this period have increased dramatically (Figure 20). Although the sources of this mortality cannot be ascertained in many cases, the leading known causes of mortality are insect damage and pathogens, which account for 38% of the mortality (Table 1). The Percent of Total Acreage Percent of Total Acreage Percent of Total Acreage Stand Age (Years) Figure 13. Age structure of various forest types in 1962 and 1985. Source: Hahn 1987. Oak, 236 Noncommercial, 217 Maple, 208 Hickory, 185 Ash, 114 Walnut, 66 Softwoods, 49 Other Hardwoods, 508 Elm, 344 OHOSOSESea Figure 14. Number (in millions) of live trees of various types in Illinois commercial forestland, 1985. majority of insect and pathogen mortality can be traced to two sources: (1) introduced pests spreading through the region (such as Dutch elm disease) or (2) decreased resistance to disease and herbivores as a result of environmental stress (such as the red spruce decline in the northeastern United States or the general forest decline in northern Europe). Examining mortality patterns by species shows that elm leads all species in mortality rates (Table 1). The majority of this mortality is the result of continued spread of Dutch elm disease in Illinois. Thus, it seems likely that the observed increase in mortality rate from 1962 to 1985 may not be symptomatic of general forest decline (Figure 20) but may indicate a peak in mortality associated with a single disease spreading through the region. There appear to be no major differences in mortality rates of trees by ownership category (Table 2). Tree Health An investigation of tree health in Illinois forests was conducted during the summer of 1992 (Iverson and Schwartz, unpublished data). For this study, the investigators followed the USDA Forest Service Forest Health Monitoring (FHM) protocol (Conkling and Byers 1992). The FHM protocol is designed to establish long-term monitoring stations from which periodic samples are collected in order to assess changes in the health and status of forests throughout the United States. The federal project is in a test phase, with current information available for only three regions (USDA Forest Service 1993, Bechtold et al. 1992). Iverson and Schwartz (unpublished data) implemented the FHM protocol in 31 forest plots across Illinois. The sites were stratified to sample each portion of the state in approximate relation to the abundance of forests within that region (Figure 21). Likewise, sampling attention was divided between upland (24 sites) and bottomland forests (7 sites) with FORESTS Other Hardwoods 1,615 Maple 1,766 Hickory 1,559 Ash 783 Cottonwood 710 Sycamore 605 Elm 463 Walnut 368 Softwoods 338 Oak 8,833 oes OHBOs8O08 Figure 15. Volume (in million board feet) of various types of trees in Illinois commercial forestland, 1985. Total volume of sawtimber was 17.5 billion board feet. 1200 3 Red Oak o@ 1000 White Oak 2 re] 2° g00 s) 5 600 = Hickory e 400 Maple ® Elm = 200 Ash {e) S Black Walnut 0 1945 1955 1965 1975 1985 Year Figure 16. Trends in volume of various types of tree, 1948-1985. respect to their relative abundances. Finally, although publicly held forestlands were primarily selected, the sample included six privately held woodlots. For each sampled plot, tree composition and health were assessed. Within tree plots sapling density, seedling recruitment, and herbaceous species cover were also sampled. To assess forest health, the follow- ing measurements are collected for trees: species, size, crown diameter, crown density, crown damage, and foliage transparency. The crown health measurements (density, damage, and transparency) can indicate symptoms of disease, herbivore damage, or environ- mental stress. While these data are most useful in subsequent re-measurements, the initial results among species were compared to determine whether certain species are showing signs of stress. In addition, the Illinois results were compared to forest health in other regions. The canopy health measurements demonstrate rela- tively low signs of damage among most species and 43 _~ ~~ FORESTS most categories (Table 3). The exceptions are a relatively high incidence of crown dieback in white oak (Quercus alba) and sugar maple (Acer saccharum) (Table 3). It is not clear why these species are showing these potential symptoms of stress. Likewise, silver maple (Acer saccharinum) and sweetgum (Liquidam- bar styraciflua) showed relatively high frequencies of low crown density (Table 3). Again, we have little information with which to interpret these data, but sweetgum is often susceptible to crown damage as a result of late spring freezes, as was the case over much the state in 1992. There did not appear to be any significant differences in tree health between upland and bottomland forests or between publicly owned versus private upland woodlands. These results also demonstrate uniformly lower levels of damage in Illinois than in comparable studies for all crown 30.0-49.9 50.0-79.9 GE 80 Figure 17. Changes in forest volume by county from 1962 to 1985, given in millions of cubic feet of sawtim- ber. [Note: for 28 counties with no coded change, no specific data were available for 1962 volumes; over all these prairie counties, however, there was a 269% increase in volume between 1962 and 1985.] damage parameters; Illinois trees appear in good health compred to those in Southern, Mid-Atlantic and New England states (Table 3). Herbaceous Species Diversity The FHM study was used to measure floristic composi- tion and diversity among Illinois forests. Three 1-m? quadrats were sampled for plant cover in each of four subplots at each site. The results indicated no differ- ences in overstory or understory species richness in forests differing in ownership category (public versus private), or in upland versus lowland forests (Table 4). Despite wide variation in the mean number of under- story species sampled (range: 3.0 to 13.8/m?), under- story diversity did not correlate well with general characteristics of the forest plot (e.g., overstory composition, tree density). Thus, although different forest types received different levels of management attention, no systematic differences in the ability of forest types to conserve forest health or species diversity were demonstrated. Further, this sampling 3.0-5.9 6.0-11.9 12.0-24.9 GE 25.0 Figure 18. Number of standard cords of fuelwood (x 1000) produced in each Illinois county, 1983. provides no specific indicators to suggest how forest diversity may be increased or maintained. Exotic Forest Weeds Exotic plant species in Illinois may be defined in three contexts—broad, narrow, and legal. In a broad sense, exotic species are those that did not naturally occur in Illinois before European settlement. This includes species that are common in surrounding states but were formerly not found in Illinois. At present, exotic species make up 28% of the Illinois flora. Table 5 shows the increase of exotic species in the flora over the past 146 years. From 1975 to 1992 the number of exotic species does not appear to have increased. In the narrow sense, exotic species are all plant species not native to North America. Seventy-eight percent of the 28% of exotic species in the Illinois flora are non- North American natives; these species thus constitute about 21% of the Illinois flora. 1900-2999 GE 3000 Figure 19. Sawlog production (in thousands of cubic feet) by county, 1985. FORESTS The legal definition of an exotic species in Illinois is provided by the Illinois Exotic Weed Act (IEWA) of 1988. It defines an exotic plant as “those plants not native to North America which, when planted, either spread vegetatively or naturalize and degrade natural communities, reduce the value of fish and wildlife and wildlife habitat, or threaten an Illinois endangered species.” (Gould and Gould 1991). Although many species fit this description, at present only three exotic species are covered by the IEWA —Japanese honey- suckle (Lonicera japonica Thunb.), multiflora rose (Rosa multiflora Thunb.), and purple loosestrife (Lythrum salicaria L.). The definition of an exotic species in the IEWA highlights some of the reasons exotic species are considered undesirable components of the Illinois flora. Some exotic species are barely able to survive in Illinois and are poorly established, but many more are widespread and aggressive in growth habit. Generally, these more successful and aggressive exotic weeds originate from an area that has a climate similar to Illinois and do well in the state in the absence of their natural pests. These exotic weeds alter the structure, species composition, and diversity of native plant communities. Table 6 lists 25 of the species that pose the most serious threat in native Illinois forest communities. Exotic weedy shrubs are currently the most serious threat to Illinois forest communities. Often these exotic shrubs were intentionally introduced by landowners and wildlife managers. The shrubs were easy to obtain, were relatively disease- and pest-free, and reproduced rapidly. Many, such as amur honeysuckle (Lonicera maackii [Rupr.] Maxim.), autumn olive (Elaeagnus umbellata Thunb.), common buckthorn (Rhamnus cathartica L.), multiflora rose, glossy buckthorn (Rhamnus frangula L.), and tartarian honeysuckle (Lonicera tatarica L.) were introduced to provide food and cover for wildlife. Some exotic shrubs, such as multiflora rose, were also used to reduce erosion, provide living fences for livestock (Albaugh et al. 1977), serve as crash barriers along highways, and reduce headlight glare in the median of highways (Schery 1977). Other shrubs, such as amur honeysuckle, Japanese barberry (Berberis thunbergii DC.), privet (Ligustrum obtusifolium Sieb. & Zucc.), tartarian honeysuckle, and winged euonymus (Euonymus alata [Thunb.] Sieb.) were frequently planted as ornamentals in Illinois. These shrubs vary widely in the severity and range of their invasion in our native forest communities. A few shrubs, such as common buckthorn, are presently of major concern in northern Illinois forests, while 45 FORESTS multiflora rose is a major problem in forests throughout Illinois. Autumn olive generally does not do well in the deep shade of Illinois forests and is more commonly encountered in disturbed or weedy areas. However, it is spread by birds that regurgitate the seeds and may quickly invade newly timbered or disturbed sites. Although first released in 1963, autumn olive was not considered to spread extensively from cultivation. The Illinois Department of Conservation began producing autumn olive in 1964, and by 1982 their nurseries were distributing more than | million autumn olive seedlings per year (Harty 1986). The Illinois Department of Conservation no longer provides autumn olive through its seedling nursery program, and the department is currently growing only native species. Nonetheless, this species is now expected to naturalize throughout the southern two-thirds of Illinois (Ebinger 1983). Another example is winged euonymus, a native to BIOMASS 0) o ® re 2 Te} =) Oo Cc 2 io Softwoods Hardwoods All Species ANNUAL HARVEST M7) wn o = AS (on) s o i re) 3s Sof = oods Hardwoods All Species China and Japan, which has been reported as rarely escaping from cultivation in the eastern United States (Gleason 1952). However, winged euonymus was first reported as naturalized in Illinois in 1973; some of the plants were more than 25 years old (Ebinger and Phillippe 1973). It is presently found in 13 counties in Illinois and undoubtedly occurs in many more. Unlike autumn olive, the winged euonymus can grow and reproduce in the dense shade of relatively undisturbed forest communities (Ebinger et al. 1984). Many exotic shrubs are now serious pests, and others have the potential to become major problems in Illinois forests. Second to the shrubs as a serious threat to Illinois forest communities are woody vines. Table 6 lists four vines causing the most problems. Japanese honey- suckle, the most troublesome exotic weedy vine, was introduced into the United States as an ornamental and ANNUAL GROWTH % of Total Biomass ANNUAL MORTALITY % of Total Biomass Hardwoods All Species Figure 20. Biomass (top left), annual growth (top right), annual harvest (bottom left), and annual mortality (bottom right) of forest growing stock, 1961 (or 1962) and 1984. Source: Hahn 1987. 46 FORESTS Table 1. Annual mortality rates for major tree species in Illinois. Data compiled by the U.S. Forest Service (1987). % annual Source (%) Species Net volume mortality Insects Disease Weather Other White Oak 1,017,620 0.535 : 45.9 - 54.1 Red Oak 1,062,426 1225 Fup! 40.8 3.8 46.7 Hickory 522,473 1.010 24.3 15.8 8.8 51.1 Basswood 54,075 1.041 - - - 100. Beech 12,096 0.405 - - - 100. Hard maple 163,083 0.658 - 51.9 - 48.1 Soft maple 341,610 1.432 34.9 - 31.0 34.1 Elm 267,399 6.449 0.8 56.3 - 42.9 Ash 260,998 0.983 - 29.5 13.0 57.5 Sycamore 134,626 1.570 - - - 100. Cottonwood 157,795 1.658 - 47.8 52.2 - Willow 50,267 1.653 - 28.0 51.1 20.8 Hackberry 93,543 1.368 - - - 100. Bigtooth Aspen 1,945 2.108 - - . 100. River Birch 36,822 1.472 - - 19.9 80.1 Sweetgum 45,077 1.477 - - - 100. Tupelo 28,043 1.590 - 51.8 - 48.2 Black Cherry 87,658 1.629 - 74.0 - 26.0 Black Walnut 119,982 1.023 - 67.2 - 32.8 Butternut 5;712 1.173 - - - 100. Yellow Poplar 51,773 1.120 - - - 100. Other 203,486 1.827 - . - 100. Jack Pine 702 0.285 - - - 100. Red Pine 11,986 0.801 : - - 100. White Pine 16,811 0.773 100. - . . Loblolly and Shortleaf Pine 64,736 0.695 - 36.9 - 63.1 Baldcypress 8,904 1.606 - - - 100. Eastern redcedar 11,359 0.607 - - - 100. Other softwoods 2,995 0.534 ——- - - 100. has been widely planted for wildlife enhancement. It Table 2. Growth and mortality rates of growing stock provides valuable cover for bobwhite quail (Colinus timber by ownership category. Data expressed as a virginianus) and turkey (Meleargris gallopavo), the percentage of the total biomass. stems and leaves serve as food for white-tail deer Ownership class Growth (%) Mortality (%) (Odocoilens virginiana), and the berries are consumed Nuviousleerest 1.90 1.16 by a number of song birds (Handley 1945). Japanese ANiee federal land 1.03 1.77 honeysuckle may be found in shaded and open condi- State 0.86 1.36 tions and, despite its ornamental use and value to County and municipal 2.25 1.59 wildlife, is a tremendous threat to native plant Forest industry 2.61 0.95 species.Although it is seldom a major concern in Farmers 1.98 1.41 established forests, when the forest is disturbed by Misc. private corp. 1.86 1.47 natural causes such as windthrow or disease, or by Misc. private individuals 2.12 1.33 human activities such as lumbering or construction, All 1.99 1.38 Japanese honeysuckle grows rapidly (Evers 1984). Rapid growth of this vine is a threat to rare native plant species and may modify natural succession. The vine may physically deform, bend, or eventually kill saplings, and foresters are sometimes reluctant to cut forests that have been invaded by Japanese honeysuckle because they fear the forest will not become reestablished following cutting (Little and Soanes 1967). 48 ____ #4FORESTS Table 3. Evaluation of health (as indicated by crown density, crown dieback, and foliage transparency) of individual forest tree species in Illinois and a compari- son of hardwood health in Illinois with that in other regions. Except for values for sample size, all numbers represent percentages of trees. Health of individual species in Illinois Crown density! n Good Average Poor White oak dd 85.7 14.3 0.0 American elm 51 68.6 31.4 0.0 Sugar maple 49 TS 24.5 0.0 Silver maple 43 65.1 32.6 2.3 Sweetgum 28 50.0 46.4 3.6 Black oak 28 85.7 14.3 0.0 Black walnut 25 88.0 12.0 0.0 Box elder 25 84.0 16.0 0.0 Red elm 23 60.9 39.1 0.0 Red oak 20 85.0 15.0 0.0 Crown dieback? None Light Moderate Severe White oak 77 93.5 3.9 0.0 2.6 American elm 51 96.1 2.0 2.0 0.0 Sugar maple 49 98.0 0.0 0.0 2.0 Silver maple 43 95.3 4.7 0.0 0.0 Sweetgum 28 100.0 0.0 0.0 0.0 Black oak 28 89.3 10.7 0.0 0.0 Black walnut 25 92.0 8.0 0.0 0.0 Box elder 25 76.0 20.0 4.0 0.0 Red elm 23 91.3 8.7 0.0 0.0 Red oak 20 85.0 10.0 5.0 0.0 Foliage transparency’ Normal Moderate Severe White oak 77 98.7 1.3 0.0 American elm 51 98.0 2.0 0.0 Sugar maple 49 100.0 0.0 0.0 Silver maple 43 100.0 0.0 0.0 Sweetgum 28 96.6 3.4 0.0 Black oak 28 100.0 0.0 0.0 Black walnut 25 100.0 0.0 0.0 Box elder 25 96.0 4.0 0.0 Red elm 23 100.0 0.0 0.0 Red oak 20 100.0 0.0 0.0 Hardwood health in Dlinois compared to that in other regions Crown density Good Average Poor Illinois* 655 75.7 23.2 1.1 Southern U.S.5 2746 37.9 61.3 0.8 New England® 2602 54.8 41.7 3.4 Mid-Atlantic® 351 68.7 30.2 1.1 Crown dieback None Light Moderate Severe Illinois 655 91.9 5.0 1.4 1.7 Southern U.S. 2746 85.1 13.1 1.3 0.4 New England 2602 78.4 17.3 2.9 1.4 Mid-Atlantic 351 70.1 29.3 0.6 0.0 Foliage transparency Normal Moderate Severe Illinois 655 75.7 23.2 1.1 Southern U.S. 2746 37.9 61.3 0.8 New England 2602 54.8 41.7 3.4 Mid-Atlantic 351 68.7 30.2 1.1 ' Crown denstiy class: good > 50%; average = 21-50%; poor < 20%. Crown dieback class: none = 0-5%; light = 6-20%; moderate = 21-50%; severe > 50%. ‘ Foliage transparency class: normal <30%; moderate = 31-50%; severe >S0%. * Data from Iverson and Schwartz, unpublished. * Data from Bechtold et al. 1992. ® Data from Eagar and Adams 1992. The herbaceous exotic weeds found in nearly all of the forests in Illinois include annual, biennial, and peren- nial herbs (Table 6). Common chickweed (Stellaria media [L.] Vill.) has been found in all 102 counties of Illinois. However, garlic mustard (Alliaria petiolata [Bieb.] Cavara & Grande) appears to be the greatest threat to Illinois forests. Introduced as a food or medicinal herb, it was first found in Cook County, Illinois, north of Chicago, in 1918. Garlic mustard readily spreads into high-quality old-growth forest and Table 4. Mean herb diversity per square meter in forest plots sampled in 1992. Herb diversity SE n Ownership (Uplands only) Public 6.53 | 19 Private 8.50 3.5 5 Forest type (public only) Upland 6.53 Sal 19 Bottomland To) 3.6 7 Figure 21. Locations of 31 study sites sampled to assess forest health in Illinois using the FHM sampling procedure (see text for additional explanation). may now be found in at least 41 counties in Illinois (Schwegman 1988, Nuzzo 1991). This biennial plant produces numerous seeds and is a major threat to FORESTS threat of garlic mustard is particularly acute since it has only recently spread through the state (Figure 22), and populations are still expanding throughout the state. Illinois’ woodland herbaceous flora, and to wildlife that depend on it for food and cover (Schwegman 1988). The Table 5. Percentage of alien species in the Illinois spontaneous vascular plant flora from 1846 to 1992. Four problematic exotic weed trees in Illinois forests are amur maple (Acer ginnala Maxim.), golden-rain tree (Koelreuteria paniculata Laxm.), tree-of-heaven (Ailanthus altissima [Mill.] Swingle), and white mulberry (Morus alba L.). Tree-of-heaven and white mulberry are found throughout Illinois. Tree-of-heaven Year of Flora author publication % alien species is especially abundant on steep slopes below the bluffs S.B. Mead 1846 10.2 of the Illinois and Mississippi rivers. Golden-rain tree, 1.A. Lapham 1857 6.6 though uncommon, has also become naturalized on H.N. Patterson 1876 15 steep slopes below the river bluffs north of Alton, W.C. Flagg and T.J. Burrill 1878 10.5 Illinois, in Madison County. Amur maple, a native of G.N. Jones 1945 15.9 central and northern Manchuria, northern China, and G.N. Jones 1950 15.9 Japan is commonly planted as an ornamental through- G.N. Jones and G.D. Fuller 1955 25.0 out Illinois. This species most commonly naturalizes in G.S. Winterringer and R.A. Evers 1960 26.0 open fields and prairies but occasionally occurs in open G.N. Jones i983 al woods and potentially may become a major weed R.M. Myers 1972 25.4 : a : : RH. Mohlenbrock 1975 79 problem in the Midwest (Ebinger and McClain 1991). R.H. Mohlenbrock and D.M. Ladd = 1978 28.7 ; nes ILPIN 1992 28.0 Exotic weeds make up more than one-fifth of Illinois’ Source: Henry and Scott 1980. flora, and they affect forest communities. The distur- Table 6. The 25 exotic weeds that pose the greatest threat to Illinois forests. Growth habit Herbs Common name Garlic mustard Ground ivy Sericea lespedeza Moneywort Eulalia Beefsteak plant Creeping smartweed Self-heal Common chickweed Shrubs Japanese barberry Autumn olive Winged euonymus Privet Amur honeysuckle Tartarian honeysuckle Common buckthorn Glossy buckthorn Multiflora rose Trees Amur maple Tree-of-heaven Golden-rain tree White mulberry Round-leaved bittersweet Climbing euonymus Japanese honeysuckle Kudzu-vine Vines Scientific name Alliaria petiolata Bieb. Glechoma hederacea L. var. micrantha Lespedeza cuneata Dum.-Cours. Lysimachia nummularia L. Microstegium vimineum Trin. Perilla frutescens L. Polygonum cespitosum var. longisetum DeBruyn Prunella vulgaris L. Stellaria media L. Berberis thunbergii DC. Elaeagnus umbellata Thunb. Euonymus alata Thunb. Ligustrum obtusifolium Sieb. & Zucc. Lonicera maackii Rupr. Lonicera tatarica L. Rhamnus cathartica L. Rhamnus frangula L. Rosa multiflora Thunb. Acer ginnala Maxim. Ailanthus altissima Mill. Koelreuteria paniculata Laxm. Morus alba L. Celastrus orbiculatus Thunb. Euonymus fortunei Turcz. Lonicera japonica Thunb. Pueraria lobata Willd. Sources: L.R. Iverson, L.R. Phillippe, and J. Schwegman, unpublished data. 49 FORESTS bance is quite variable in degree and may affect any stratum. In areas severely invaded by exotic shrubs and vines, succession may be altered so the structure of the forest is drastically changed. Exotic weeds also alter the biodiversity of Illinois forests. Japanese honey- suckle and multiflora rose are two exotic weeds recognized by the IEWA that pose serious threats to the forests of Illinois, and for these species, “It shall be unlawful for any person, corporation, political subdivi- sion, agency or department of the State to buy, sell, offer for sale, distribute or plant seeds, plants, or plant parts, of exotic weeds without a permit issued by the Department of Conservation” (Gould and Gould 1991). Exotic weeds are a serious problem in Illinois forests, and recovery depends on the appropriate actions taken and enforced, such as those stated in the Illinois Exotic Weed Act. Threatened and Endangered Forest Plants Threatened and endangered plants make up 17% of our native Illinois flora. Threatened plants are those likely to become endangered within the foreseeable future, and endangered plants are those in danger of extirpa- tion from Illinois. Three hundred fifty-six taxa are listed as threatened or endangered under the Illinois Endangered Species Act (Herkert 1991). Forty-nine percent of these taxa have been found in the forests of Illinois. Thirty-three threatened taxa are listed in Table 7, and 142 endangered taxa are listed in Table 8. Of the 172 vascular plant families in the Illinois flora (Mohlenbrock 1986), 32% are represented by these threatened and endangered forest taxa. The sedge family (Cyperaceae) has the most taxa (22), followed by the grass family (Poaceae) with 14, and the aster (Asteraceae) and orchid (Orchidaceae) families with 10 each. Fourteen percent of the Illinois genera of vascular plants are represented by these threatened and endan- gered forest taxa. Sedge (Carex) is the most repre- sented taxa (18), followed by panic grasses (Panicum) with 5, and grape ferns (Botrychium) and bluegrasses (Poa) with 4 each. Most of these threatened and endangered species are at the edge of their natural distribution. Forty-four percent have primarily north or northeastern affinities, 31% have primarily south or southeastern affinities, 20% have primarily eastern affinities, and the remaining 5% have western, southwestern, or midwestern affinities. These species include 17 trees, 20 shrubs, 6 woody vines, 19 ferns and fern allies, 13 annual or biennial herbs, and 99 perennial herbs. 200 ° uo ° ° Cumulative Number uo ° of Observations 1920 1930 1940 1950 1960 1970 19860 1990 Year Figure 22. Spread of garlic mustard (Alliaria petiolata), an exotic weedy pest species, through Illinois, as demonstrated by the cumulative number of occurrences by decade. Data are from Nuzzo (1993) and are based on herbarium collections, sight observa- tions, and literature references. Of the 175 threatened and endangered taxa in the forests of Illinois, 15 listed as state endangered have not been seen in the past 20 years. These species are Price’s groundnut (Apios priceana Robins), screwstem (Bartonia paniculata [Michx.] Muhl.), dwarf grape fern (Botrychium simplex E. Hitchc.), lined sedge (Carex striatula Michx.), spotted wintergreen (Chimaphila maculata {L.] Pursh), finger dog-shade (Cynosciadium digitatum DC.), moccasin flower (Cypripedium acaule Ait.), northern cranesbill (Gera- nium bicknellii Britt.), cow wheat (Melampyrum lineare Desr.), long-leaved panic grass (Panicum longifolium Torr.), white mountain mint (Pycnanthemum albescens Torr. & Gray), round-leaved shinleaf (Pyrola americana Sweet), goldenrod (Sol- idago arguta Ait.), nodding trillium (Trillium cernuum L.), and deerberry (Vaccinium stamineum L.). Two Illinois state-endangered species, Price’s ground- nut and small whorled pogonia (/ostria medeoloides [Pursh] Raf.), are also federally listed species. Price’s groundnut, a perennial herbaceous vine, is a federally threatened species, which means it is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. Price’s groundnut is known only from Alabama, Illinois, Kentucky, Mississippi, and Tennessee. In Illinois, Price’s groundnut was collected in Union County in 1941. Its collection location has been repeatedly searched, but Price’s groundnut has not been relocated in Illinois (Bowles et al. 1991). Small whorled pogonia, a perennial herb, is a federally ———————————— ee eee eee ee FORESTS ——_ endangered species, which means it is in danger of extinction or of extirpation from a significant portion of its range. Although small whorled pogonia is known from a number of states, it is often found in only small numbers. In Illinois, for example, small whorled pogonia is known from a single population in Randolph County (Herkert 1991). About 50 taxa formerly known from Illinois are thought to be extirpated from the state (Page and Jeffords 1991). Twelve are forest species: eight monocots and four dicots. The two flowering plant families with the most extirpated species are the grasses with four and the orchids with three. The monocots are drooping wood reed (Cinna latifolia [Trev.] Griseb.), bluebead lily (Clintonia borealis [Ait.] Raf.), brown plume grass (Erianthus brevibarbis Michx.), adder’s mouth orchid (Malaxis unifoia Michx.), rice grasses (Oryzopsis asperifolia Michx. and Oryzopsis pungens [Torr.] Hitche.), Hooker’s orchid (Platanthera hookeri Torr.), and round-leaved orchid (Platanthera orbiculata [Pursh] Torr.). The four dicots are trailing arbutus (Epigaea repens L. var. glabrifolia Fern.), twin- flower (Linnaea borealis L. ssp. americana [Forbes] Hulten), flowering wintergreen (Polygala paucifolia Willd.), and false bugbane (Troutvetteria caroliniansis [Walt.] Vail). Six species (bluebead lily , trailing arbutus, twinflower, rice grass, round-leaved orchid, and flowering winter- green) are northern Illinois taxa, one (Hooker’s orchid) is a northern and western Illinois taxon, one (drooping wood reed) is a northern and southern Illinois taxon, three (adder’s mouth orchid, rice grass, false bugbane) Table 7. Threatened vascular plants in Illinois forests. All taxa are perennial unless otherwise stated. Ferns Scientific name Botrychium multifidum (Gmel.) Rupr. Gymnosperms Dicots Monocots Asplenium bradleyi D.D. Eat. Asplenium resiliens Kunze Dennstaedtia punctilobula (Michx.) Thuja occidentalis L. Larix laricina (DuRoi) Aristolochia serpentaria L. var. hastata (Nutt.) Matelea obliqua (Jacq.) Aster furcatus Burgess Aster schreberi Nees Aster undulatus L. Circium carolinianum (Walt.) Helianthus angustifolius L. Solidago sciaphila Steele Lonicera flava Sims Sambucus pubens Michx. Euonymus americanus L. Lathyrus ochroleucus Hook. Quercus phellos L. Quercus prinus L. Trientalis borealis Raf. Rubus pubescens Raf. Sullivantia renifolia Rosendahl Besseya bullii (Eat.) Rydb. Styrax americana Lam. Viola conspersa Reichenb. Scirpus polyphullus Vah\ Polygonatum pubescens (Willd.) Stenanthium gramineum (Ker) Trillium viride Beck Veratrum woodii Robbins Corallorhiza maculata Raf. Oryzopsis racemosa (J.E. Smith) Common name Growth habit Northern grape fern Evergreen Bradley’s spleenwort Evergreen Black spleenwort Evergreen Hay-scented fern Deciduous Arbor vitae Tree Tamarack Tree Virginia snakeroot Herb Climbing milkweed Herb; vine Forked aster Herb Schreber’s aster Herb Wavy-leaved aster Herb Carolina thistle Herb; biennial Narrow-leaved sunflower Herb Cliff goldenrod Herb Yellow honeysuckle Woody vine Red-berried elder Shrub Strawberry bush Shrub Pale vetchling Herb Willow oak Tree Rock chestnut oak Tree Star flower Herb Dwarf raspberry Shrub Sullivantia Herb Kitten tails Herb Storax Shrub Dog violet Herb Bulrush Herb Downy Solomon’s seal Herb Grass-leaved lily Herb Green trillium Herb False hellebore Herb Spotted coral-root orchid Herb Rice grass Herb 52 _______ FORESTS Table 8. Endangered vascular plants in Illinois forests. All taxa are perennial unless otherwise stated. Fern allies Equisetum pratense Ehrh. Ferns Gymnosperms Dicots Scientific name Equisetum scirpoides Michx. Equisetum sylvaticum L. Lycopodium dendroideum Michx. Lycopodium clavatum L. Botrychium biternatum (Sav.) Botrychium matricariaefolium A. Br. Botrychium simplex E. Hitche. Cystopteris laurentiana (Weath.) Blasd. Dryopteris celsa (Wm. Palmer) Small Gymnocarpium dryopteris (L.) Newm. Gymnocarpium robertianum (Hoffm.) Newn. Thelypteris noveboracensis (L.) Nieuwl. Thelypteris phegopteris (L.) Slosson Woodsia ilvensis (L.) R. Br. Pinus echinata Mill. Pinus resinosa Ait. Justicia ovata (Walt.) Lindau Adoxa moschatellina L. Tresine rhizomatosa Standl. Conioselinum chinense (L.) BSP Cynosciadium digitatum DC. Ptilimnium costatum (Ell.) Raf. Ptilimnium nuttallit (DC.) Britt. Matelea decipiens (Alex.) Woods Eupatorium incarnatum Walt. Lactuca hirsuta Muhl. Melanthera nivea (L.) Small Solidago arguta Ait. Berberis canadensis P. Mill. Betula alleghaniensis Britt. Betula populifolia Marsh. Hackelia americana (Gray) Fern. Lonicera dioica L. var. glaucescens Rydb. Viburnum molle Michx. Stellaria pubera Michx. Cornus canadensis L. Corylus cornuta Marsh. Melothria pendula L. Gaultheria procumbens L. Vaccinium stamineum L. Amorpha nitens Boyn. Apios priceana Robins Astragalus crassicarpus Nutt. var. trichocalyx Cladastris lutea (Michx. f.) K. Koch Dioclea multiflora (Torr. & Gray) Trifolium reflexum L. Castanea dentata (Marsh.) Borkh. Quercus nuttallii Palmer Bartonia paniculata (Michx.) Muhl. Geranium bicknellii Britt. Carya pallida (Ashe) Engl. & Graebn. Pycnanthemum albescens Torr. & Gray Pycnanthemum torrei Benth. Synandra hispidula (Michx.) Baill. Common name Meadow horsetail Dwarf scouring rush Horsetail Ground pine Running pine Southern grape fern Daisyleaf grape fern Dwarf grape fern Laurentian fragile fern Logfern Oak fern Scented oak fern New York fern Long beech fern Rusty woodsia Shortleaf pine Red pine Water willow Moschatel Bloodleaf Hemlock parsley Finger dog-shade Mock Bishop’s weed Mock Bishop’s weed Climbing milkweed Thoroughwort Wild lettuce White melanthera Goldenrod Allegheny barberry Yellow birch Gray birch Stickseed Red honeysuckle Arrowwood Great chickweed Bunchberry Beaked hazelnut Squirting cucumber Wintergreen Deerberry Smooth false indigo Price’s groundnut Large ground plum Yellowwood Boykin’s dioclea Buffalo clover American chestnut Nuttall’s oak Screwstem Northern cranesbill Pale hickory White mountain mint Mountain mint Hairy synandra Growth habit Deciduous Evergreen Deciduous Evergreen Evergreen Evergreen Deciduous Deciduous Deciduous Deciduous Deciduous Deciduous Deciduous Deciduous Deciduous Tree Tree Herb Herb Herb Herb Herb Herb; annual Herb; annual Herb; vine Herb Herb; biennial Herb Herb Shrub Tree Tree Herb Woody vine Shrub Herb Herb Shrub Herb; annual vine Subshrub Shrub Shrub Herb; vine Herb Tree Herb; vine Herb; annual/biennial Tree Tree Herb Herb; annual/biennial Tree Herb Herb Herb; annual/biennial Table 8 (continued) ee SSeS Monocots Scientific name Circaea alpina L. Oxalis illinoensis Schwegman Corydalis aurea Willd. Plantago cordata Lam. Lysimachia fraseri Duby Lysimachia radicans Hook. Chimaphila maculata (L.) Pursh Chimaphila umbellata (L.) Bart. Pyrola americana Sweet Cimicifuga americana Michx. Cimicifuga racemosa (L.) Nutt. Clematis crispa L. Clematis occidentalis (Hornem.) DC. Clematis viorna L. Berchemia scandens (Hill) K. Koch Amelanchier interior Nielsen Amelanchier sanguinea (Pursh) DC. Malus angustifolia (Ait.) Michx. Rosa acicularis Lindl. Rubus enslenii Tratt. Rubus odoratus L. Sorbus americana Marsh. Waldsteinia fragarioides (Micxh.) Tratt. Populus balsamifera L. Bumelia lanuginosa (Michx.) Pers. Ribes hirtellum Michx. Saxifraga virginiensis Michx. Collinsia violacea Nutt. Melampyrum lineare Dest. Penstemon brevisepalus Pennell Halesia carolina L. Styrax grandifolia Ait. Tilia heterophylla Vent. Planera aquatica (Walt.) J.F. Gmel. Ulmus thomasii Sarg. Urtica chamaedryoides Pursh Viola canadensis L. Viola incognita Brainerd Sagittaria longirostra (Micheli) J.G. Sm. Carex alata Torr. & Gray Carex brunnescens (Pers.) Poir. Carex canescens L. var. disjuncta Fern. Carex communis Bailey Carex decomposita Muhl. Carex gigantea Rudge Carex intumescens Rudge Carex laxiculmis Schwein. Carex nigromarginata Schwein. Carex oxylepis Torr. & Hook. Carex physorhyncha Liebm. Carex prasina Wahlenb. Carex reniformis (Bailey) Small Carex striatula Michx. Carex styloflexa Buckl. Carex tuckermanii Boott Carex willdenowii Schkuhr Common name FORESTS ——— — Growth habit Small enchanter’s nightshade Herb Illinois wood sorrel Golden corydalis Heart-leaved plantain Loosestrife Creeping loosestrife Spotted wintergreen Pipsissewa Round-leaved shinleaf American bugbane False bugbane Blue jasmine Mountain clematis Leatherflower Supple-jack Shadbush Shadbush Narrow-leaved crabapple Rose Arching dewberry Purple-flowering raspberry American mountain ash Barrens strawberry Balsam poplar Wooly buckthorn Northern gooseberry Early saxifrage Violet collinsia Cow wheat Short-sepaled beard tongue Silverbell tree Bigleaf snowbell bush White basswood Water elm Rock elm Nettle Canadian violet Hairy white violet Arrowhead Winged sedge Brownish sedge Sedge Fibrous-rooted sedge Cypress-knee sedge Large sedge Swollen sedge Spreading sedge Black-edged sedge Sharp-scaled sedge Bellow’s bead sedge Drooping sedge Reniform sedge Lined sedge Bent sedge Tuckerman’s sedge Willdenow’s sedge Herb Herb; biennial Herb Herb Herb Herb Herb Herb Herb Herb Woody vine Woody vine Woody vine Woody vine Shrub Shrub Tree Shrub Shrub Shrub Tree Herb Tree Shrub Shrub Herb Herb; annual Herb; annual Herb Shrub Shrub Tree Shrub Tree Herb; annual Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb Herb 54 ______ FORESTS Table 8 (continued) Scientific name Carex woodii Dewey Cyperus lancastriensis Porter Fimbristylis annua (All.) Roem. & Schult. Scirpus verecundus Fern. Luzula acuminata Raf. Lilium superbum L. Medeola virginiana L. Trillium cernuum L. Trillium erectum L. Cypripedium acaule Ait. Cypripedium calceolus L. var. parviflorum (Salisb.) Cypripedium reginae Walt. Hexastylis spicata (Walt.) Barnh. Isotria medeoloides (Pursh) Raf. Isotria verticillata (Willd.) Raf. Platanthera clavellata (Michx.) Luer Platanthera flava (L.) Lindl. var flava Platanthera psycodes (L.) Lindl. Glyceria arkansana Fern. Gymnopogon ambiguus (Michx.) BSP. Milum effusum L. Panicum joorii Vasey Panicum longifolium Torr. Panicum ravenelii Scribn. & Merr. Panicum stipitatum Nash Panicum yadkinense Ashe Poa alsodes Gray Poa autumnalis Muh. Poa languida A.S. Hitche. Poa wolfii Scribn. Schizachne purpurascens (Torr.) Swallen are west-central Illinois taxa, and one (brown plume grass) is a southern Illinois taxon. All of these species are more common outside Illinois. FOREST ANIMALS Trends in Wildlife Habitat Illinois forests provide the major habitat for more than 420 vertebrate species, and losses in the quality and quantity of that habitat severely affect wildlife popula- tions (Illinois Wildlife Habitat Commission 1985). Of the more than 420 vertebrates listed as occurring in Illinois by the Illinois Fish and Wildlife Information System (IFWIS-Illinois Department of Conservation/ Illinois Natural History Survey), 82.5% of the mam- mals, 62.8% of birds, and 79.7% of the amphibians and reptiles require forested habitat for a portion of their life cycle. Clearly, forests are an important component Common name Growth habit Pretty sedge Herb Galingale Herb Baldwin’s fimbristylis Herb; annual Bashful bulrush Herb Hairy woodrush Herb Turk’s cap lily Herb Indian cucumber root Herb Nodding trillium Herb Ill-scented trillium Herb Moccasin flower Herb Small yellow lady’s slipper Herb Showy lady’s slipper Herb Crested coralroot orchid Herb Small whorled pogonia Herb Whorled pogonia Herb Wood orchid Herb Tubercled orchid Herb Purple-fringed orchid Herb Arkansas manna-grass Herb Beard grass Herb Millet grass Herb Panic grass Herb Long-leaved panic grass Herb Ravenel’s grass Herb Tall flat panic grass Herb Panic grass Herb Grove bluegrass Herb Autumn bluegrass Herb Weak bluegrass Herb Wolf’s bluegrass Herb False melic grass Herb of maintaining vertebrate diversity in Illinois. A more fine-tuned method of summarizing the value of Illinois wildlife habitat is based on land use. Complete details are presented in Graber and Graber (1976), and revised calculations based on current data are given in Iverson et al. (1989). The habitat evaluation index devised by Graber and Graber is based on the relative amount of a particular habitat type within a given area, the avail- ability of that habitat type within the state or region, the changing availability of that habitat, and the “cost” of a given habitat measured in years required to replace the ecosystem. A summary of habitat factors (which sum to the habitat evaluation index) for Illinois as a whole, as of 1985, is presented in Table 9. By this calculation, over three-quarters of the wildlife habitat (88 of 115.73 habitat factor points) is derived from forests. Elm-ash- cottonwood rates highest because this forest type has been disappearing so quickly over the past two decades (Figure 11). Oak-hickory values would be higher except that numbers in older age classes are increasing as secondary forests mature, even though numbers in younger age classes are decreasing (Figure 11). A very minor rating was earned by maple-beech because this forest type has increased so dramatically in recent years (Figure 9). Habitat factor scores were generally much more favorable for wildlife habitat in the southern half of the state, which has more forests. In fact, the total habitat factor scores for the south region were twice those of the central region, with the north region being in between (Iverson et al. 1989). By comparing the habitat factor scores obtained by Iverson et al. (1989) for 1985 data to those of Graber and Graber (1976) for 1973 data, one can evaluate the temporal trends in habitat and the role of forestland in those changes. This evaluation was possible for three regions of the state—north, central, and south (caution is advised in this comparison, however, because the three regions do not exactly match geographically). It was not possible to directly compare the habitat scores between dates because of slight variations in the methodology. However, by calculating the percentage of the habitat factor occupied by each land type for the two dates, one can evaluate relative contributions to habitat by each land type over time (Figure 23). Total contributions of forestland to habitat can also be calculated. For example, in the north, the cumulative percentage from forest was 53.4% in 1973 and 65.3% in 1985—a 22% increase in relative habitat from forests in that region (Figure 23). The increase is mostly due to large increases in relative habitat factors for the elm-ash-cottonwood and pine types and a decrease in the marsh habitat factor. In the central Table 9. Habitat factors for Illinois, 1985, calculated according to Graber and Graber (1976). Habitat % of wildlife Land type factor habitat Forest Pine 5.70 4.9 Oak-hickory 30.07 26.0 Oak-gum-cypress 11.97 10.3 Elm-ash-cottonwood 40.19 34.7 Maple-beech 0.14 0.1 Subtotal 76.0 Nonforest Cropland 0.29 0.3 Pasture/hayland 10.01 8.7 Prairie 1.46 1.3 Marsh 15.28 13.2 Water 0.38 0.3 Urban, residential 0.03 0.0 Fallow 0.19 0.2 Subtotal 24.0 Total 115.73 100.0 FORESTS region, relative habitat increased from 71.6% to 76.1% (Figure 23), while in the south region, relative habitat decreased from 88% to 84% (Figure 23). In all regions, there were increases in relative habitat factors for elm- ash-cottonwood because the type decreased in area by nearly 50% during that time period (Figure 13). Oak- gum-cypress, likewise, increased in all regions (Figure 23) as a result of increasing availability in younger age classes (Figure 11). Pine scores increased in the northern region (Figure 23) because its availability increased, especially in the older (> 40 year) age class. In contrast, all regions showed a decrease in relative habitat value for the oak-hickory type and the maple- Cumulative Percentage from Forest: 1973: 53.4% 1985: 65.3% — | 31973 01985 Fallow Small Grain Residential Prairie Pasture/Hay Row Crop Cumulative Percentage from Forest: 1973: 71.6% 1985: 76.1% OGC OH Pine Marsh Fallow EAC MB Small Grain Residential Praine Pasture/Hay Row Crop Cumulative Percentage from Forest: 1973: 88.0% 1985: 84.0% occ OH Pine Marsh Fallow Small Grain Residential Praine Pasture/Hay Row Crop Figure 23. Relative habitat factors for three regions in Illinois in 1973 and 1985. OGC = oak-gum-cypress, EAC = elm-ash-cottonwood, OH = oak-hickory, MB = maple-beech. 56 FORESTS beech type, but for different reasons. The oak-hickory type decreased because regeneration is not occurring, resulting in a loss of acreage (to maple) (Figure 11); habitat factor scores were especially reduced in the young age classes. The maple-beech type decreased in relative habitat value because of the extremely large increases in area (Figure 11), resulting in very low changing availability scores, which caused the habitat factor scores to be very low as well. Overall, the data show the extremely high value of forests for wildlife habitat across the state and how the value of forests for wildlife is increasing. Geographical Patterns in Abundance of Major Vertebrates Beginning in 1991, Illinois began an ongoing project to systematically inventory incidental wildlife observa- tions of bow-and-arrow hunters in 10 regions of the state (see Figure 24). Although we have only one year of data, several noteworthy features have become apparent. First, on a statewide basis nothing is close to deer and squirrel in abundance (Table 10). This report is supported by estimates of densities of up to 30 deer per square mile of forested habitat (Gladfelter 1984), and a statewide population of up to 500,000 deer (C. Nixon, Illinois Natural History Survey, personal communication). In interpreting these data, however, one should bear in mind that the hunters were in search of deer and that other common forest animals, such as raccoon, are nocturnal. The data for predators show that coyotes are the most frequently observed species and that they increase in abundance toward the southern end of Illinois (Table 10). In contrast, the number of observations of red fox was highest in the northern portion of the state (Table 10). Likewise, badger observations increased in the southern regions, while grey fox showed no strong geographical trend (Table 10). The data for game birds indicate that turkey, the most frequently observed game bird, reached peak densities along the western rim of the Illinois (Table 10). Not surprisingly, pheasant were observed most frequently in those regions dominated most strongly by agricultural lands (e.g., Grand Prairie and Central Sand Prairie) and in the northern portion of the state (Table 10). Quail showed no strong geographical trends in observation frequency. Squirrels were observed more frequently in the southern end of the state, whereas deer and rabbit observations peaked in the northern regions (Table 10). Finally, both raccoon and housecat observations outpaced opossum and skunk observations in all regions, with no strong geographical pattern detected in any group (Table 10). Trends in Forest Birds In many regions of North America, forest habitat islands harbor relatively few species of forest birds. Concern is deepest for species that breed in North America and migrate to winter in Central or South America. These species are commonly called long- distance or neotropical migrants and include warblers, vireos, and tanagers. Do islands of forest habitat in Illinois support viable populations of forest songbirds? Trends in species diversity and abundances of breeding birds within woodlots of various sizes were examined to assess this question. Long-term data are especially useful because abundances of birds and other wildlife fluctuate even under a stable habitat. Owing to the work of the late Dr. S. Charles Kendeigh, studies of forest songbirds in the heavily farmed landscapes of east-central Illinois extend back to the late 1920s and, in some cases, continued through the mid-1970s. In 1992, birds were censused on two areas used by Kendeigh: Trelease Woods and Allerton Park (J. Brawn, Illinois Natural History Survey, unpublished data). Trelease Woods is a 24-ha woodlot surrounded by agricultural fields. The Allerton Park study plot is a 24-ha area within a 600-ha forest. Two variables are assessed in this report: numbers of species found breeding on the study areas (total and neotropical migrants) and the proportion of neotropical migrants found within the areas (relative abundances). The number of breeding species neither increased nor decreased overall (Figure 25). Annual fluctuations were common, but for all species and for neotropical migrants, numbers of species did not decrease mark- edly. In fact, on Trelease Woods, numbers of species increased during the 1950s and have remained com- paratively high. These data confirm numerous other studies that report higher numbers of species of neotropical migrants within larger tracts of forests than smaller tracts. Figure 26 illustrates distinct decreases in relative abundances of neotropical migrants on both plots. Data for many more years are available for Trelease Woods, but on both plots relative abundances decreased markedly in the 1950s and remained low (importantly, abundances of two pest species, starlings [Sturnus vulgaris] and brown-headed cowbirds [Molothorus Table 10. Numbers of various species of wildlife observed by bow-and-arrow hunters in 10 regions of Illinois.* Values represent the number of animals observed per 1000 hunter-hours. Region Missouri Grand Species NW Hills NE Moraine BorderN Prairie W Prairie Squirrel 824 719 864 817 892 Rabbit 7 14 15 17 8 Deer 1046 992 635 895 711 Coyote 21 20 st) 36 50 Red fox 15 12 16 9 8 Grey fox 1 6 2 2 2 Badger 1 0 0 0 1 Pheasant 23 26 1 22 6 Quail 3 2 45 2 50 Turkey 334 6 147 23 95 Raccoon 31 34 31 30 22 Housecat 21 31 17 16 16 Opossum 3 9 7 24 3 Skunk 1 g 1 1 1 * For a depiction of the 10 regions, see Figure 24 (below). MISSISSIPPI mS Figure 24. Illinois regions in which wildlife observa- tions of bow-and-arrow hunters were inventoried. See Table 10 (above). Central Sand Missouri Wabash Shawnee Avg. for Prairie BorderS_ S Plain Border Hills Illinois 969 1014 1141 999 1064 912 4 4 6 4 5 11 792 723 791 884 887 850 74 33 51 68 71 40 15 13 12 10 9 11 2 4 4 5 4 3 1 5 1 0 5 1 21 0 0 0 0 12 14 15 29 4 7 15 39 151 43 32 140 83 49 23 23 41 18 28 13 12 20 18 14 18 1 1 2 2 2 3 Z 2 0 0 2 1 ater], were factored out of this analysis). These changes have brought about a dramatic change in the nature of breeding bird communities on the study areas and, likely, throughout Illinois. Neotropical migrants formerly accounted for over 70% of the breeding birds. Now they account for less than 50%—even on large woodlots. On small woodlots, like Trelease Woods, the problem appears extreme because the migrants account for only 25% of all resident birds. In summary the analyses indicate that few, if any, species have been lost during the 20th century, but that a large group of species may be in trouble. If trends persist, one-third to one-half the species typical of Illinois’ forests may disappear from many areas. Forest Insects The many species of trees found in the forests of Illinois serve as food for a great diversity of insects. In more northerly regions, by contrast, the limited number of tree species supports a more limited insect fauna. With a high diversity of tree species and of insects, there appear to be more factors, such as predators and parasites, that limit the possibility of severe outbreaks of any given insect species. In contrast, agricultural crops planted as monocultures provide many examples of great buildups of an insect species that can devastate the crop. Likewise, near monocultures of spruce and fir dominate many regions of Canada and the northern states. In these areas, periodic outbreaks of the spruce budworm result in the defoliation and death of thou- sands of acres of forest. Although forest monocultures of pine are not uncommon in Illinois, most forests FORESTS ——— _______ FORESTS Numbers of Species Breeding Trelease Woods - 24 ha © 2 E 3 z 1927 1932 1937 1942 1947 1952 1957 1962 1967 1972 1977 1982 1987 1992 Census Year —* All Species -®@- Migrants Numbers of Species Breeding Allerton Park - 600 ha = © 2 E 3 2 1949 1955 1961 1967 1973 1979 1985 1991 Census Year —* All Species -&- Migrants Figure 25. Number of bird species breeding in two woodland units from 1927 to 1992. consist of mixed stands of many tree species. Thus, even though a given tree species may be seriously affected by an insect or pathogen, as in the case of Dutch elm disease, the forest is buffered from total loss. As the Illinois landscape changed from a mixture of prairie and forest to agriculture, so too were there probable changes in the insect fauna that flourished in forests. There were no insect surveys prior to or during the earlier periods of European development, so we cannot determine what native insects may have been lost through settlement. We do know from some historical data that the original upland forests were almost exclusively mixed deciduous forest dominated by oaks and hickories. Insect species that flourish in undisturbed forests include cicadas, many species of Relative Abundances of Migrants Trelease Woods - 24 ha 75 = 50 - ° | od a) = 25 = 1927 1932 1937 1942 1947 1952 1957 1962 1967 1972 1977 1982 1987 1992 Census Year Relative Abundances of Migrants Allerton Park - 600 ha 75 = s Po r 50 - ° x 25 1949 1955 1961 1967 1973 1979 1985 1991 Census Year Figure 26. Relative abundance of migrant birds in two woodland study units from 1927 to 1992. cerambycid beetles, carpenterworms, and clearwing moths. Populations of such species probably declined as forestlands were cleared. Logged areas that were allowed to regenerate as second-growth forest sup- ported dramatically different insect communities. Populations of native species such as the eastern tent caterpillar, fall webworm, and yellownecked caterpillar probably flourished as they do today in similar areas. The tree species diversity of the regenerated forests was not as great as it was in the former stands, and thus insect populations may have fluctuated more dramati- cally. Since the 1930s there has been an increase in the number of acres of pine planted in Illinois. Insect pests native to the United States such as the northern pine weevil, pales weevil, and Nantucket pine tip moth are now quite common throughout Illinois in areas in which they formerly did not exist because their host trees were absent. In 1979, pine wilt disease, which is caused by a nematode that infects the native Carolina pine sawyer beetle, was discovered in Illinois. Thus, a native insect is acting as a vector for an exotic disease. The disease has devastated red and Scotch pine plantations through- out the state. Exotic Insect Pest Introductions With industrial development in the mid-1800s came the increased possibility of the accidental introduction of insect pests. Several important exotic insect pests of forests that are now established in Illinois include the European elm scale, the smaller European elm bark beetle, European pine shoot moth, European pine sawfly, gypsy moth, and common pine shoot beetle. Sometime in the late 1800s the European elm scale was found in the United States. The first Illinois record is unknown, but it probably was in the early 1900s. The scale insect injures young elm trees. Heavily infested trees are stunted. In urban areas elm trees often become heavily infested, which kills some tree limbs. In 1909, the first report of the smaller European elm bark beetle was made in Boston, Massachusetts. The first incidence of Dutch elm disease in Ohio was 1930, and in Illinois the first record was 1950. The smaller European elm bark beetle is the vector of the fungus that causes Dutch elm disease. During the 1950s through the 1970s, Dutch elm disease eliminated nearly all American elm in the forests of Illinois. In Illinois today, American elm trees exist only in limited numbers and only in communities where strict regula- tions dictate the rapid removal of dead trees. The European pine shoot moth was found in Illinois in 1914. The borer infests Scotch, red, and Austrian pines. The larva bores into the new growth of pines, thereby causing a reduction in growth and disfiguration of the tree. This insect infests pines in the northern half of Illinois. The first report of the European pine sawfly in the United States was recorded in New Jersey in 1925. The sawfly is now well established in the pine forests east of the Mississippi River, from the northern half of Illinois eastward, including southern Canada. Severe defoliation of red, Scotch, and Austrian pines occurs during population outbreaks. FORESTS The gypsy moth became established in Massachusetts in 1869 and spread westward. To date the gypsy moth has not been permanently established in Illinois; however, since 1981 male moths have been captured in pheromone traps placed in locations throughout the state. The number of male moths caught in Illinois has increased since 1986. This trend will probably con- tinue, due to the increased mobility provided by our modern transportation system which aids in the dispersal of egg masses from infested into noninfested areas. Most of the moths have been captured in the five-county area surrounding Chicago. Once the gypsy moth becomes established in Illinois it could have a devastating effect on oak stands throughout the state. Woodlands that are already under stress are particularly susceptible to diseases after gypsy moth defoliation. For more details on gypsy moth invasion to Illinois see the chapter on agricultural lands. If it were not for the control programs enacted by the Illinois Department of Agriculture and the USDA APHIS in the early 1980s, the gypsy moth would undoubtedly be well established in Illinois today. The number of sites with gypsy moths, however, continues to increase. Soon it may be impossible to contain the infestations. An outbreak of gypsy moths in Illinois, probably beginning in the Chicago region, seems inevitable. Infestation patterns in other states suggest that the deciduous forests of Illinois, with abundant oaks, would be severely afffected by such an outbreak. Many deciduous trees that are in a weakened condition will be killed. Understory plants that cannot tolerate direct sunlight during the period of defoliation in June will also be severely affected. The experience of eastern states suggests that forest plant communities will dramatically change as a direct result of the gypsy moth. The most recent exotic insect introduction into Illinois is the common pine shoot beetle. The beetle was found in August of 1992 in a pine planting in Kane County. The beetle is a common forest pest in Europe, where it destroys the current year’s growth of pine twigs. Beetle populations can build to large numbers in dead pine trees and pine stumps. The insect could pose a threat to certain Illinois pine plantations where dead trees are not removed and where pine stumps are not treated or removed. Quarantine regulations and control measures will soon be in effect to curtail the spread of the beetle and possibly to eliminate it from the state. Many commercial pine stands will probably be eliminated by the late 1990s because of pine wilt disease. 59 60 ____ S FORESTS Under current global trade patterns, with weak restric- tions on importation of plant material, exotic insect pest introductions are likely to continue. Some of these pests will become established, causing both ecological and economic effects on the forests of Illinois. FOREST CONSERVATION ‘Numerous types of land are used to preserve biological diversity in Illinois forests (for example, state parks and nature preserves). One major concern for conserva- tion of this biological diversity is undesired changes in community composition among forests through time. Early settler records suggest that most northern and central Illinois upland forests were open mature forests dominated by oaks and hickories (Anderson 1991). The abundance of oak-hickory forest was maintained through occasional fire (Anderson 1991). After European settlement, forests that were not logged began to change as a result of fire suppression. These changes continue today, as witnessed by the rapidly increasing amount of sugar maple and beech forest types within the state (Figure 11). This transition from oak-hickory forests to sugar maple forests has dimin- ished overall forest quality by reducing species diversity (Wilhelm 1991). From an economic perspective, this shift in community composition toward sugar maple is also viewed unfavorably because sugar maple is a lower value timber product than either oaks or hickories. With respect to other conservation efforts, recent evidence suggests that clear-cutting of forests erodes the habitat’s ability to maintain populations of wild- flowers (Duffy and Meier 1992). Clear-cutting causes severe damage to the understory herb layer, and it appears that this herbaceous flora does not recover during a typical growth cycle between cutting events. A recent trend that has ameliorated this effect is that the managers of Shawnee National Forest are now moving away from the use of clear-cutting in sites that support native forest species. Forest size is an important predictor of habitat quality. Of the 214 grade A and B forest sites classified by the Illinois Natural Areas Inventory (White 1978), only 11% are greater than 100 acres (Figure 27). By contrast, among all forest parcels in Illinois, 55.7% are greater than 100 acres (Figure 28), indicating that our large forest patches are less frequently of high quality than we would expect. This is likely to be the result of large tracts being used for intensive logging. At the same time, 19% of sites classified as grade A or B forest are so small (less than 10 acres) that they may experience severe problems maintaining biological diversity (Figure 27). Even the majority of the grade A and B forest sites (20-50 acres, Figure 27) are prone to edge and small patch size effects. To put this in perspective, if a 40-acre site were square, there would be no place in this forest more than 220 yards from an edge. Given that most forest patches are linear strips along waterways, most high quality forest is within 100-200 yards of a habitat border (see subsequent section in this report on forest fragmentation). Finally, the data on grade A and B sites show that there are very few sites supporting flatwood or sand forest vegetation, making them critically threatened habitats (Figure 27). Sand Forests Flatwoods Floodplain Forests Uplend Forests Beas Number of Sites 0-5 5-10 10-20 20-50 50-100 >190 Acreage Categories Figure 27. Size distribution of grade A and B forest parcels identified by the Illinois Natural Areas Inven- tory (White 1978) for each of four forest types. 40-99 acres, 4,479 (2.7) 100-200 acres, 2,476 (1.5) 201-600 acres, 2,099 (1.3) 601-1,100 acres, 525 (0.3) > 1,100 acres, 542 (0.3) Figure 28. Number of forested parcels in Illinois by size and average number of parcels per township equivalent (36 square miles). The total number of parcels of a given size is the number immediately following the size; the average number of parcels of a given size per township is given in parentheses. Source: U.S. Geological Survey land-use data, 1973-1981. STRESSORS Pollution Ozone, NO,, and SO, are among the numerous anthro- pogenic pollutants that pose well-documented threats to forested habitats (see Schulze et al. 1989, Johnson and Lindberg 1992, Eagar and Adams 1992). Case studies demonstrate the severe effects of pollutants on ecosystem function in forested habitats (e.g., Johnson and Lindberg 1992). Further, widespread pollutants have been implicated in forest declines (e.g., Schulze et al. 1989, Eagar and Adams 1992). In particular, pollutants increase levels of stress in trees (Johnson and Fernandez 1992, McLaughlin and Kohut 1992). Stress increases the susceptibility of trees to other sources of mortality such as plant pathogens (Schoeneweiss 1975, 1978; Manion 1981). Studies of the abiotic environment suggest that Illinois does not, as of yet, suffer from the same levels of acid rain that have been implicated in the decline of forests in the northeastern United States or northern Europe. The pollutant deposition data are supported by recent data indicating lower overall forest damage in Illinois than other regions of the eastern United States (Table 3). Deforestation A recent study comparing plant composition in Appalachian old-growth and second-growth forests showed that herbaceous species diversity does not recover following clear-cutting, not even after 80 years (Duffy and Meier 1992). Similarly, the long-term effect of past clear-cutting in Illinois may have been to reduce the biodiversity of Illinois forests. Illinois forests are going through a process of maturation (Figure 13), and these younger stands may require specific management to recover natural levels of biodiversity. We need additional research to assess the potential damage in Illinois, as well as management programs to restore woodland habitats. Fortunately, most current forestry operations in Illinois employ less destructive selective logging techniques to harvest timber. Nonetheless, we need additional reserach on the long-term impact of selective logging on forest biodiversity. Fragmentation The Illinois forested landscape, as discussed above, is extremely fragmented. According to U.S. Geological Survey data, there were 10,121 forested parcels of 40 acres or more in Illinois in 1980. These parcels averaged 358 acres, and about 44% of the parcels were 100 acres or less (Figure 28). There were an average of FORESTS 6.1 parcels per township (an area of 36 square miles). Of course, the density of forest patches was much higher in the southern counties. Fragmentation of forest habitat has negative implica- tions for biological diversity at many levels. First, many plants and animals may need large blocks of uninterrupted forest for successful reproduction (e.g., see Robinson 1988, Blake 1991). Several studies have found that small habitat patches tend to be dominated by generalist birds, and as habitat size increases, the diversity of birds requiring specialized habitats also increases (Martin 1981, Whitcomb et al. 1981, Ambuel and Temple 1983, Blake and Karr 1987). In an exami- nation of forest patch use in Illinois by migrant and resident birds in 1979 and 1980, Blake (1991) found that there is a high level of predictability of habitat patch use based on the size of the patch. In studying habitat use on 12 forest remnants that varied from 1.8 to 600 hectares, Blake found that small patches (< 20 hectares) were dominated by generalist birds. Second, as large tracts of forest area are broken into small, isolated woodlots, more forest edge is created and more opportunities exist for edge-adapted species to usurp habitat from forest-interior species. In a study of old-growth forest fragments in Indiana, Brothers and Spingarn (1992) found that 21 species of alien plants had invaded the forests. While the number of species (species richness) of the alien flora invading the forest fragments dropped dramatically just 2 m inside the forest edge (compared to 2 m outside the forest edge— Figure 29), the frequency of alien species (compared to native species) remained above 20% over 20 m into the forest in many instances (Figure 29). Further, the frequency of alien species was higher on south-facing edges than on north-facing edges. These results suggest that an important aspect to consider in forest fragments is the edge-to-center ratio (or perimeter-to-area ratio) of individual fragments. Increasing edges of fragments increases the probability of invasion by species from other habitats. In Illinois, much of our remaining forests occurs as one of two types: (1) very small, isolated patches where the edge-to-center ratio is very high and (2) riparian zone forests where there is practically no center and lots of edge. Both of these forest fragment types are very susceptible to the negative effect of habitat edges. The conclusion that habitat edges should be minimized runs counter to traditional wildlife management goals to establish habitat edges to enhance populations of deer, pheasant, and other species valued primarily by hunters. Although it is difficult to estimate 61 62 FORESTS presettlement deer populations, we know that popula- tions increased in the 1800s in association with land clearing (Torgerson and Porath 1984). During the early 20th century, deer populations were very low but have rebounded substantially during the past 30 years (Gladfelter 1984, Torgerson and Porath 1984). This increase is, in part, a result of managing forestlands for habitat openings and food plots (Gladfelter 1984). Although the current abundant deer populations are viewed favorably by hunters, they appear to pose serious threats to biological diversity in forests (Ander- son and Loucks 1979, Alverson et al. 1988, Strole and Anderson 1992, Anderson and Katz 1993). This conflict between the conservation of plant diversity and Ea warm (S/W) aspects [) Cool (N/E) aspects Exotic Species Richness -2 2 8 20 50 Distance From Edge (m) 100 so ay EB warm (S/W) aspects > 2 [4 Cool (N/E) aspects OO 60 c oO oa a” 22 40 yi cS 20 0 Distance From Edge (m) Figure 29. Mean alien species richness (top) and mean frequency of sample transect segments contain- ing alien species (bottom), summarized by transect position and aspect. Sample size = 7 for each combina- tion of transect and aspect. Redrawn from Brothers and Spingarn (1992). deer points out an inherent problem with managing biological resources: species-based management goals often conflict with those developed to maintain the full array of native biodiversity. Third, fragmentation of forests into small habitat islands results in small effective population sizes. Population size is the best predictor of extinction probability. Population Viability Analysis (PVA) is a tool used to predict the likelihood that a population will persist through time (Gilpin and Soule 1986). Recent reviews of PVA (Soule 1987; Shaffer 1981, 1987; Menges 1992) conclude that, in general, effects attributable to environmental stochasticity are most likely to cause population extinction. Further, populations of fewer than 200 individuals are moderately susceptible to extinction through environmental sto¢hasticity (Menges 1992). Because most Illinois forests are very small, many species may be restricted to small popula- tions. Thus, fragmentation may increase the propensity for small, isolated populations to become locally extirpated. Finally, the disjunction of forest patches may inhibit movement of individuals—particularly, several species of plants, insects, and small mammals—between isolated habitats. This spatial isolation may, in turn, result in genetic isolation. Genetic isolation can be detrimental to the long-term health of resident popula- tions because it increases inbreeding, which can lead to an erosion of the genetic variability and, eventually, of the viability of these populations (see discussion in prairie chapter on genetic concerns). Inbreeding depression is likely to become a problem over the short term for certain types of organisms. Organisms that disperse well— such as birds, large mammals, trees, and many robust insects—are likely to maintain substantial gene flow despite habitat fragmentation. For organisms that live very long—such as trees, some shrubs, perennial herbs, and fungi—any increase in inbreeding is likely to take a very long time to erode local variability to the point where populations may become inviable. In contrast, organisms that do not disperse well and have short generation times (e.g., small mammals, sedentary insects, and short-lived herbs) may show severe inbreeding problems over the course of a few generations (Barrett and Kohn 1991). There is little direct evidence with which to gauge the magnitude of inbreeding depression effects in Illinois at the present time. Global Climate Change and Carbon Dioxide Sequestration Because Illinois has undergone massive changes in total forest volume over the past several decades, the amount of carbon being sequestered into Illinois forest biomass has likewise changed considerably. From 1948 to 1962, there was a slight loss of total forest volume due to conversion of forestland to other uses (Figures 16, 30). This loss was compensated by the harvesting of wood products, which put 0.29 million metric tons of carbon into long-term storage. The result was that forestlands were a net sink of 0.2 million metric tons of carbon per year during 1948-1962. After 1962, there was a gain in forestland and especially a gain in forest volume per unit of forestland; in addition, carbon sequestration into long-term storage of wood products increased slightly. The net result was carbon sequestra- tion of about 1.37 million metric tons of carbon per year from 1962 to 1985 (Figure 30). Even though the amount of carbon sequestered by Illinois forests has increased, however, this amount still represents only about 2.7% of the total carbon emissions that the people of Illinois contribute to the atmosphere each year. Ecological Response to Global Climate Change Predictions of global warming suggest, barring extreme global restrictions on the use of fossil fuels, that atmospheric CO, levels will double during the next century. This doubling of CO, is predicted to result in a global increase in temperature of between 1.5°C and HB Chonge in Volume Ba Chonge in Lond Use B Long-term Storage °o °o Total Annual Sink: 0.2 million m tons C ° Annuel Carbon Sink million metric tons ° ° Total Annual Sink: 1.37 million m tons C ' ° 1946-1962 1962-1965 Figure 30. Carbon sinks and sources related to Illinois forestlands, 1948-1985. Depicted are amounts of carbon sequstration due to changes in the volume of trees per unit of forest area, changes in land use, and changes in the long-term storage of carbon as a result of the harvesting of timber products. FORESTS 4.5°C (Houghton et al. 1990). Average increases are expected to be from 0.2°C to 0.3°C per decade (Houghton et al. 1990). Temperature changes will not be evenly distributed around the globe, with the greatest temperature changes at high latitudes, and particularly during the winter months (Houghton et al. 1990). In addition, mid-continental regions should, in general, experience a decrease in growing season precipitation and an increase in the frequency of drought events. However, the predictions with respect to precipitation are much less firm than those for temperature. These climate changes may have several biological ramifications. First, warmer winter temperatures are likely to result in increased survivorship of over- wintering insects. This may pose problems with respect to both pests of forests and crop plants, some of which now over-winter south of Illinois. Second, increased drought frequency may result in increased frequencies of plant disease (Schoeneweiss 1975, 1978; Manion 1981). Given that the major identifiable sources of mortality in trees are insects and disease (Table 1), climate change is likely to exacerbate existing prob- lems. In addition, climatic warming may result in earlier spring greening of vegetation (M.D. Schwartz 1990, 1992), enhanced net growth rates (Melillo et al. 1990), increased levels of herbivory (Melillo et al. 1990), and shifts in the competitive interactions among species (Melillo et al. 1990). All of these indirect effects are likely to alter the ability of Illinois forests to support timber production in, as yet, unpredictable ways. The primary realm of uncertainty in these predictions of changes due to increases in temperature relates to the numerous direct effects of atmospheric CO, on plants (for reviews, see Melillo et al. 1990, M.W. Schwartz 1992). For example, an increase in atmo- spheric co, levels: (a) decreases water stress (Farquhar and Sharkey 1982), (b) increases plant growth rates (Bazzaz and Carlson 1984, Idso et al. 1987), (c) alters nutrient uptake rates (Luxmoore et al. 1986), (d) alters phenology (Long and Huichin 1991), and (e) changes plant tissue chemistry and subsequent rates of her- bivory (Lincoln and Couvet 1989). Most of the changes in direct response of plants to increases in CO, levels will ameliorate the effects of climate change. We remain far from being able to predict these responses with any certainty. Situated at the edges of southern and northern forests, and along the eastern edge of the prairie, Illinois is in a position—if climatic warming occurs as predicted—to lose many plant species from northern counties while FORESTS acquiring new species in southern counties as range limits shift northward (Davis 1989). While the retrac- tion of southern range boundaries may be rapid in response to climate change, the movement of northern edges of distributions is likely to be quite slow (M.W. Schwartz 1992, 1993). Thus, if warming proceeds as climate change models predict, Illinois may experience a net decrease in natural biological diversity. LITERATURE CITED Albaugh, G.P., W.H. Mitchell, and J.C. Graham. 1977. Evaluation of glyphosphate for multiflora rose control. Proceedings of the Northeastern Weed Science Society 31:283—291. Alverson, W.S., D.M. Waller, and S.L. Solheim. 1988. Forest to deer: edge effects in northern Wisconsin. Conservation Biology 2:348-358. Ambuel, B., and S.A. Temple. 1983. Area-dependent changes in the bird communities and vegetation of southern Wisconsin forests. Ecology 64:1057—1068. Anderson, R.C. 1991. Presettlement forests of Illinois. Pages 9-20 in G.V. Burger, J.E. Ebinger, and G.S. Wilhelm, eds. Proceedings of the Oak Woods Management Workshop. Eastern Illinois Univer- sity, Charleston, Illinois. Anderson, R.C., and O.L Loucks. 1979. White-tail deer (Odocoileus virginianus) influence on structure and composition of Tsuga canadensis forests. Journal of Applied Ecology 16:855-861. Anderson, R.C., and A.J. Katz. 1993. Recovery of browse-sensitive tree species following release from white-tailed deer (Odocoileus virginianus Zimmerman) browsing pressure. Biological Conservation 63:203-—208. Barrett, S.C.H., and J.R. Kohn. 1991. Genetic and evolutionary consequences of small population size in plants: implications for conservation. Pages 3-30 in D.A. Falk and K. E. Holsinger, eds. Genetics and Conservation of Rare Plants. Oxford University Press, New York. Bazzaz, F.A., and R.W. Carlson. 1984. The response of plants to elevated CO,. I. Competition among an assemblage of annuals at different levels of soil moisture. Oecologia 62:196—198. Bechtold, W.A., W.H. Hoffard, and R.L. Anderson. 1992. Summary report: forest health monitoring in the south, 1991. Gen. Tech. Rep. SE-81. USDA Forest Service, Southeastern Forest Experiment Station, Asheville, NC. 40 p. 64 Blake, J.G. 1991. Nested subsets and the distribution of birds on isolated woodlots. Conservation Biology 5:58-66. Blake, J.G., and J.R. Karr. 1987. Breeding birds of isolated woodlots: area and habitat relationships. Ecology 68:1724-1734. Bowles, M.L., J.B. Taft, E.F. Ulaszek, M.K. Solecki, D.M. Ketzner, L.R. Phillippe, A. Dennis, P.J. Burton, and K.R. Robertson. 1991. Rarely seen endangered plants, rediscoveries, and species new to Illinois. Erigenia 11:27-51. Brothers, T.S., and A. Spingarn. 1992. Forest fragmen- tation and alien plant invasion of central Indiana old-growth forests. Conservation Biology 6:91— 100. Conkling, B.L., and G.E. Byers, eds. 1992. Forest health monitoring field methods guide. Internal report. U.S. Environmental Protection Agency, Las Vegas, Nevada. Davis, M.B. 1989. Lags in vegetation response to greenhouse warming. Climate Change 15:75-82. Duffy, D.C., and A.J. Meier. 1992. Do Appalachian herbaceous understories ever recover from clear- cutting? Conservation Biology 6:196—201. Eagar, C., and M.B. Adams. 1992. Ecology and decline of red spruce in the eastern United States. Ecologi- cal Studies 96. Springer-Verlag. New York. 417 p. Ebinger, J.E. 1983. Exotic shrubs a potential problem in natural area management in Illinois. Natural Areas Journal 3:3-6. Ebinger, J.E., and W.E. McClain. 1991. Naturalized amur maple (Acer ginnala Maxim.) in Illinois. Natural Areas Journal 11:170-171. Ebinger, J.E., J. Newman, and R. Nyboer. 1984. Naturalized winged wahoo (Euonymus alatus) in Illinois. Natural Areas Journal 4:26—29. Ebinger, J.E., and L.R. Phillippe. 1973. New plant records for Illinois. Transactions of the Illinois State Academy of Science 66:115. Essex, B.L., and D.A. Gansner. 1965. Illinois’ timber resources. U.S. Department of Agriculture, Forest Service, Resource Bulletin LS-3. St. Paul, Minnesota. 56 p. Evers, J.E. 1984. Japanese honeysuckle (Lonicera japonica): a literature review of management practices. Natural Areas Journal 4:4—10. Farquhar, G.D., and T.D. Sharkey. 1982. Stomatal conductance and photosynthesis. Annual Reviews of Plant Physiology 33:317-345. Gilpin, M.E., and M.E. Soule. 1986. Minimum viable populations: processes od species extinction. Pages 19-34 in M.E. Soule, ed. Conservation biology: The science of scarcity and diversity. Sinauer Assoc. Inc. Sunderland, Massachusetts. Gladfelter, H.L. 1984. Midwest agricultural region. Pages 427-440 in L.K. Halls, ed. White-tailed deer ecology and management. Stackpole Books. Harrisburg, Pennsylvania. Gleason, H.A. 1952. The New Britton and Brown illustrated flora of the northeastern United States and adjacent Canada. 3 volumes. Lancaster Press, Lancaster, Pennsylvania. Gould, J.B., and L. Gould. 1991. Illinois Exotic Weed Act. Illinois Conservation Law. Chapter 5, §932. Definition, §933. Exotic weeds, §934. Exotic weed control. Illinois Conservation Law, Binghamton, New York. Graber, J.W., and R.R. Graber. 1976. Environmental evaluations using birds and their habitats. Illinois Natural History Survey Biological Notes 97. 39 p. Hahn, J.T. 1987. Illinois forest statistics, 1985. U.S. Department of Agriculture, Forest Service, Resource Bulletin NC-103. St. Paul, Minnesota. 101 p. Handley, C.O. 1945. Japanese honeysuckle in wildlife management. Journal of Wildlife Management 9:261-264. Harty, F.M. 1986. Exotics and their ecological ramifi- cations. Natural Areas Journal 6:20—26. Henry, R.D., and A.R. Scott. 1980. Some aspects of the spontaneous Illinois vascular flora. Transactions of the Illinois State Academy of Science 73:35—40. Herkert, J.R.,ed. 1991. Endangered and threatened species of Illinois: status and distribution. Volume I—Plants. Illinois Endangered Species Protection Board, Springfield. 158 p. Houghton, J.T., G.J. Jenkins, and J.J. Ephraums. 1990. Climate change: the IPCC scientific assessment. Cambridge University Press, Cambridge. 365 p. Idso, S.B., B.A. Kimball, M.G. Anderson, and J.R. Mauney. 1987. Effects of atmospheric CO, enrichment on plant growth: the interactive role of air temperature. Agriculture, Ecosystems and the Environment 20:1—10. Illinois Wildlife Habitat Commission. 1985. The crisis of wildlife in Illinois today. Illinois Wildlife Habitat Commission, Springfield. 26 p. Iverson, L.R., and D.M. Ketzner. 1988. The Illinois Plant Information Network user’s guide. Internal document. Illinois Natural History Survey, Champaign. 92 p. Iverson, L.R., R.L. Oliver, D.P. Tucker, P.G. Risser, C.D. Burnett, and R.G. Rayburn. 1989. Forest resources of Illinois: an atlas and analysis of spatial and temporal trends. Illinois Natural History Survey Special Publication 11. 181 p. FORESTS Johnson, A.S., W.M. Ford, P.E. Hale. 1993. The effects of clearcutting on herbaceous understories are still not fully known. Conservation Biology 7:433-435. Johnson, D.W., and S.E. Lindberg. 1992. Atmospheric deposition and forest nutrient cycling. Ecological Studies 91. Springer-Verlag, New York. 707 p. Johnson, D.W., and I.J. Fernandez. 1992. Soil mediated effects of atmospheric deposition on eastern U.S. spruce-fir forests. Pages 235-270 in C. Eagar and M.B. Adams, eds. Ecology and decline of red spruce in the eastern United States. Ecological Studies 96. Springer-Verlag, New York. 417 p. Klopatek, J.M., R.J. Olson, C.J. Emerson, and J.L. Jones. 1979. Land-use conflicts with natural vegetation in the United States. Environmental Conservation 6:191—198. Lincoln, D.E. and D. Couvet. 1989. The effects of carbon supply on allocation to allelochemicals and caterpillar consumption of peppermint. Oecologia 78:112-114. Little, S. and H.A. Soanes. 1967. Results of herbicide trials to control Japanese honeysuckle. U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station Research Note 62:1—8. Hamden, Connecticut. Long, S.P., and P.R. Hutchin. 1991. Primary produc- tion in grasslands and coniferous forests in relation to climate change: an overview of information available for modelling change in this process. Ecological Applications 1:139—156. Luxmoore, R.J., E.G. O'Neill, J.M. Ellis, and H.H. Rogers. 1986. Nutrient uptake and growth response of Virginia pine to elevated atmospheric CO,,. Journal of Environmental Quality 15:244—-251. Manion, P.D. 1981. Tree disease concepts. Prentice Hall. 399 p. Martin, T.E. 1981. Limitation in small habitat islands: chance or competition? Auk 98:715—733. McCurdy, D.R., and D.C. Mercker. 1986. A study of owners of large, private, forested tracts in southern Illinois, 1977-1985. Department of Forestry, Southern Illinois University at Carbondale. 18 p. McLaughlin, S.B., and R.J. Kohut. 1992. The effects of atmospheric deposition and ozone on carbon allocation and associated physiological processes in red spruce. Pages 338-384 in C. Eagar and M.B. Adams, eds. Ecology and decline of red spruce in the eastern United States. Ecological Studies 96. Springer-Verlag, New York. 417 p. Melillo, J.M., T.V. Callaghan, F.I. Woodward, E. Salatki, and S.K. Sinha. 1990. Effects on ecosystems. Pages 283-310 in J.T. Houghton, G.J. Jenkins and JJ. 65 FORESTS Ephraums, eds. Climate change: the IPCC scientific assessment. Cambridge University Press, Cambridge. Menges, E.S. 1992. Stochastic modeling of extinction in plant populations. Pages 253-276 in P.L. Fiedler and S.K. Jain, eds. Conservation biology: the theory and practice of nature conservation, preservation, and management. Chapman and Hall, New York. Mohlenbrock, R.H. 1986. Guide to the vascular flora of Illinois. Southern Illinois University Press, Carbondale. 507 p. Nuzzo, V.A. 1993. Current and historic distribution of garlic mustard (Alliaria petiolata) in Illinois. Michigan Botanist 32:23-33. Osborne, L.L., and M.J. Wiley. 1988. Empirical relation- ships between land use/cover and stream water quality in an agricultural watershed. Journal of Environmental Management 26:9-27. Page, L.M., and M.R. Jeffords, eds. 1991. Our living heritage: the biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4):357-477. Robinson, S.K. 1988. Reappraisal of the costs and benefits of habitat heterogeneity for nongame wildlife. Transactions of the North American Wildlife and Natural Resources Conference. 53:145-155. Schery, R. 1977. The curious double life of Rosa multiflora. Horticulture 55:56-61. Schoeneweiss, D.E. 1975. Predisposition, stress, and plant disease. Annual Review of Phytopathology 13:193-211. Schoeneweiss, D.E. 1978. Water stress as a predispos- ing factor in plant disease. Pages 61-99 in T.T. Kozlowski, ed. Water deficits and plant growth. Volume 5. Academic Press, New York. Schulze, E.D., O.L. Lange, and R. Oren. 1989. Forest decline and air pollution. Ecological Studies 77. Springer-Verlag, New York. 475 p. Schwartz, M.D. 1990. Spring phenology: nature’s experiment to detect the effect of “green-up” on surface maximum temperatures. Monthly Weather Review 118:883-890. Schwartz, M.D. 1992. Phenology and springtime surface-layer change. Monthly Weather Review 120:2570-2578. Schwartz, M.W. 1992. Potential effects of global climate change on the biodiversity of plants. Forestry Chronicle 68:462-471. Schwartz, M.W. 1993. Modelling effects of habitat fragmentation on the ability of trees to respond to climatic warming. Biodiversity and Conservation 2:51-61. 66 Schwegman, J. 1988. Illinois garlic mustard alert!! Illinois Department of Conservation, Division of Natural Heritage, Springfield. 1 p. Shaffer, M.L. 1981. Minimum population sizes for species conservation. Bioscience 31:131—134. Shaffer, M.L. 1987. Minimum viable populations: coping with uncertainty. Pages 69-86 in M.E. Soule, ed. Viable populations for conservation. Cambridge University Press, Cambridge. Soule, M.E. 1987. Viable populations for conservation. Cambridge University Press. Cambridge. Strole, T.A. and R.C. Anderson. 1992. White-tailed deer browsing: species preferences and implica- tions for central Illinois forests. Natural Areas Journal 12:139-144. Telford, C.J. 1926. Third report on a forest survey of Illinois. Illinois Natural History Survey Bulletin 16:1-102. Torgerson, O. and W.R. Porath. 1984. Midwest oak/ hickory forest. Pages 411-426 in L.K. Halls, ed. White-tailed deer ecology and management. Stackpole Books, Harrisburg, Pennsylvania. U.S. Forest Service. 1949. Forest resources of Illinois. U.S. Department of Agriculture, Forest Service, Central States Forest Experiment Station Forest Survey Release 7. Columbus, Ohio. 53 p. U.S. Forest Service. 1993. Northeastern Area Forest Health Report. NA-TP-03-93. United States Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 57 p. Whitcomb, R.F., C.S. Robbins, J.F. Lynch, B.L. Whitcomb, M.K. Klimkiewicz, and D. Bystrak. 1981. Effects of forest fragmentation on avifauna of the eastern deciduous forest. Pages 123—205 in R.L. Burgess and D.M Sharpe, eds. Forest island dynamics in man-dominated landscapes. Springer- Verlag, New York. White, J. 1978. Illinois Natural Areas Inventory technical report. Vol. 1. Survey method and results. Illinois Department of Conservation, Department of Landscape Architecture at the University fof Illinois at Urbana-Champaign, and Natural Land Institute, Springfield, Illinois. 426 p. Wilhelm, G.S. 1991. Implications of changes in floristic composition of the Morton Arboretum’ s east woods. Pages 31-54 in G.V. Burger, J.E. Ebinger, and G.S. Wilhelm, eds. Proceedings of the Oak Woods Management Workshop. Eastern Illinois University, Charleston, Illinois. Young, R., M. Reichenbach, and F. Perkuhn. 1984. A survey of private non-industrial forest owners in Illinois: a preliminary report. University of Illinois Forestry Research Report 84—2. 5 p. AGRICULTURAL LANDS SUMMARY The nature of agriculture and the impact of farming on environmental conditions in Illinois are closely tied to trends in cropping systems, livestock production, soils, and the chemical and mechanical inputs used to produce farm products. Crop rotations that traditionally included soil-building forage legumes and small grains have diminished as the production of corn and soybeans (row crops) has increased—a trend that has been particularly important since the early 1960s. The expanded production of row crops and emerging farm technologies have led to increasing crop production per unit of land and more farmland planted in crops. Technological advances affecting yields include improved plant hybrids, inor- ganic fertilizers, and a plethora of pesticide compounds. Chemical and mechanical disturbances (inputs) are fundamentally important to describing environmental trends because they constitute the primary disturbances on farmland. Important mechanical disturbances include the types of farm machinery and agronomic practices used for crop planting, cultivation, and harvest. Because agriculture in Illinois is characterized by chemical- and mechanical-intensive technologies, four major issues are typically discussed at the state level regarding agriculture and the environment. These include (1) soil conservation, erosion, and the accelerated sedimentation of rivers and lakes; (2) use of nitrogen fertilizer on cropland and increasing contamination of water supplies by nitrates and other fertilizer compounds; (3) extensive pesticide use and the contamination of water supplies with pesticide residues, which may affect human health and wildlife; and (4) the impact of farming on biodiversity and wildlife on farmland. There has been progress in soil conservation, but achieving soil and water quality goals in Illinois remains a foremost challenge for agriculture. Likewise, integrated pest management has been successful in using host plant resistance and biological control to suppress agricultural pests, but chemical control is still a widely used option for economic reasons in agriculture and for public health reasons in mosquito control. The decline in the abundance of upland game species since the 1960s is a case study of how intensive agricul- ture has negatively affected habitat for many wildlife species traditionally common to the farm landscapes of Illinois. The decline in upland game populations and other farmland wildlife is due to expanded row crop production and the loss of small grains and perennial vegetation including hay and the loss of uncropped farm- land such as wetlands, savannas, and permanent pasture. INTRODUCTION Farms dominate the landscape of Illinois. In fact, over 80% of the 35.7 million acres of Illinois land is currently in farms. Most of the farmland is planted in row crops, some is planted with perennial hay or orchard crops, and a small fraction is pasture and woodland. Approximately two-thirds of the farmland, and therefore half of Illinois, is planted in the primary row crops, corn and soybeans. Clearly, an assessment of critical environmental trends must consider the impact agricultural practices and farmland have on the state. In addition, the activities of industries and cities will influence plants and animals that inhabit farmland. This second perspective is necessary because cropland, pasture, and woodlands on farms create a diverse landscape ranging from field to orchard, from windrow to pasture, and from windbreak to woodland. The diversity and abundance of plant and animal species may be lower per acre on agricultural land than on other types of land, but the large amount of farmland in Illinois means that agricultural lands provide many resources for wild and managed animals and plants. Typically, four major concerns are discussed at the state level about agriculture and the environment. The first involves soil conservation, erosion, and the sedimentation of rivers and lakes. Illinois has the world’s best soils for crop production. These soils were created by the plants and small animals living in the wetlands, prairies, and forests that existed in Illinois before humans cultivated the land. Second, the use of nitrogen fertilizers, crop yields, and nitrate contamination of water supplies have all 67 68 AGRICULTURAL LANDS increased since 1940. Efforts are being made to optimize, and often reduce, total nitrogen applications to cropland to maintain yields of corn while protecting groundwater and surface water. Third, pesticide use and residues in water supplies are a major concern because of possible effects on human health and wildlife. The most common herbicides are being found in groundwater samples taken from wells across the state. Insecticides may harm birds, mam- mals, bees, or fish depending on the type of chemical and its concentration. For the past 20 years, integrated pest management has attempted to optimize—and where possible, reduce—chemical pesticide use while decreasing damage by pests. Nevertheless, insect, weed, and fungus abundance and pressure on crops from these pests have not declined over the past decades. The fourth important concern is biodiversity and wildlife on farmland. Some wild plants and animals inhabit the margins between wild and managed areas or inhabit managed woodlands on farms. Often cropland or pastures provide part of the resources necessary for the survival of wildlife populations. This is especially true in regions of the state without large natural areas. This chapter describes farm production trends and key environmental factors such as vulnerability of soils to erosion, agrichemical use, crop pests, and wildlife. In addition, other data are described that may help us manage agricultural and neighboring lands to deal with the four major concerns described previously. CRITICAL INDICATORS OF AGRICULTURAL LAND CONDITIONS The nature of agriculture and the impact of farming on environmental conditions of Illinois are closely tied to trends in cropping systems, livestock production, soils, and the chemical and mechanical inputs used to produce farm products. Chemical and mechanical disturbances (inputs) are fundamentally important to describing environmental trends because they constitute the primary disturbances on farmland. Key chemical inputs include the use of inorganic fertilizers, insecticides, and herbicides. Natural and anthropomorphic forces move these chemical compounds through the atmosphere and through other terrestrial and aquatic environments. In fact, farm chemicals are a major source of nonpoint- source pollution in Illinois. The status of major agricultural pests is also an important consideration because chemical, biological, and mechanical controls of pests bear upon environmental quality. Important mechanical disturbances include the farm machinery and agronomic practices used for crop planting, cultivation, and harvest. Mechanical distur- bances, in conjunction with soil properties and chemi- cal inputs, affect soil and water quality; that is, they affect the extent to which runoff and leaching of chemicals are significant nonpoint sources of pollution. For over 150 years agriculture has been the most important determinant of biodiversity in Illinois. Trends in biodiversity, the numbers of endemic plant and animal species present, indicate the extent to which fundamental ecosystem processes have been altered by humans and, in a broader sense, indicate the health of the environment. In addition to biodiversity, the abundance of key wildlife species traditionally com- mon to Midwestern farm landscapes is a measure of how suitable agricultural lands are for important game species. Trends in Agricultural Land, Products, and Tillage Farmland consists of cropland, pasture, and woodlands on farms. Figure 1 shows that while the amount of farmland has decreased approximately 10% since 1950, the average size of an Illinois farm has more than doubled during the same period. Figure 2 shows how average farm size has changed in Illinois counties since 1964. Since the 1960s, the number of acres of cropland has declined in urban and heavily forested counties (Figure 3). In general each unit of cropland has become more productive. Corn yield and the All Crop Produc- tion Index (CPI) calculated by the Illinois Department of Agriculture have increased over the past 40 years in Illinois, primarily because of increased inputs of synthetic fertilizers and pesticides (Figure 4). Since 1945 a variety of federal farm programs have resulted in the diversion of cropland from crop produc- tion to other uses, including fallow, for short or long periods of time (Figures 5 and 6). Cropland diverted from production has been relatively common in the 1980s throughout the state. Diverted cropland is important (when managed appropriately) for protecting soils. Cropland diverted from production under long- term contract (such as the Conservation Reserve Program) is typically established in perennial grasses and other vegetation valuable for building and protect- ing soil. However, the extent to which land diverted AGRICULTURAL LANDS 32000 [==] FARMLAND 350 ae —+— FARM SIZE 300 S 31000 : a = 30500 250 & Z 30000 | ins x : 29500 | | ie 29 | > Sel ae 4 28000 100 : % 27500 | ieee | "2 pero 0 Bae gs eri): es. egg eres ey Figure 1. Amount of farmland and average farm size in Illinois in recent decades. Source: Illinois Department of Agriculture. Cro] Le -6 ets F FESS 6 to 15 FRB «GE 16 Figure 2. Percent increase in acres per farm ‘in Illinois Figure 3. Percent change in acres of cropland in counties, 1964 to 1987. Source: U.S. Department of Illinois counties, 1964 to 1987. Source: U.S. Depart- Commerce, Bureau of the Census. ment of Commerce, Bureau of the Census. 69 AGRICULTURAL LANDS from production under annual contract has achieved soil and water quality goals has not been monitored. Since World War II agriculture has moved from relatively small, diversified farming systems to large, highly specialized cash grain units. As cropping systems have changed in recent decades, key animal, mechanical, and chemical disturbances have also changed. Crop rotations that traditionally included soil- building forage legumes and small grains have dimin- ished (Figure 7) as the production of corn and soybeans (row crops) has increased—a trend that has been particularly important since the early 1960s (Figure 8). Since 1964, the amount of land planted in soybeans has increased dramatically in most counties (Figure 9), while the changes in corn acreage have been more varied (Figure 10). Rotation of corn and soybeans every other year is good for pest management, but soybean production can increase soil erosion. Compar- ing county-level trends from 1964 to 1987 shows that production of oats has generally increased, especially in the southern half of Illinois (Figure 11), while production of hay has generally declined (Figure 12). However, oat plantings in 1987 were unusually high because 30% of the corn base was diverted from crop production that year—most of which was planted to oats. Wheat production was lower in 1987 than in 1964 except in the extreme northwest and south (Figure 13). [3 CROP eae PRODUCTION 120.0 INDEX (CPI) A ——#—— CORN YIELD = 100.0 (BU/ACRE) Z 80.0 e) O 2 60.0 = °40.0 O 20.0 0.0 19450 $709908 ie LISS 1960 mall 1965 1970.) 1975.6" (1980. ..1985 Because of this expansion of soybean and corn production, mechanical disturbances of the soil have greatly increased since World War II. Fall tillage (using primarily the moldboard plow) increased from the early 1950s through the late 1970s (Figure 14). Conservation tillage, which is defined as at least 30% of the soil surface protected by crop stubble after spring planting, has increased sharply during the 1980s with the adoption of no-till planting systems and other tillage implements that reduce soil disturbance (Figures 15 and 16). Although Illinois has led the nation in the adoption of conservation tillage during much of the 1980s, an extensive amount of cropland with highly erodible soils remains susceptible to erosion (Figure 17). There has been progress in soil conservation, but achieving soil and water quality goals in Illinois remains a foremost challenge for agriculture. Areas producing fruits and vegetables tend to receive extensive amounts of commercial fertilizers and pesticides to control plant diseases, insects, and weeds. Therefore, trends in orchard and vegetable production are important from an environmental standpoint. Although orchard and truck gardens are significant to local economies, the production of fruits and veg- etables is declining. In 1991, snap beans, asparagus, and sweet corn were produced on about 29,000 acres, down from about 43,000 acres in 1984. The production Figure 4. Crop production index and corn yields in Illinois in recent decades. Source: Illinois Department of Agriculture. AGRICULTURAL LANDS 5000 |_] SHORT TERM 4500 LONG TERM | 4000 3500 L] INTERMEDIATE n ACRES (1000s) 1945. “50 55 60 3000 + 2500 7 2000 in 1500 : ali 1000 : | , : 500 0 Hi }} 4} | int WUE Bone 15 t28 At 70 80 85 Figure 5. Amount of cropland diverted from production by various farm programs in recent decades in Illinois. Values are given for long-term (>5 years), intermediate (3—5 years), and short-term (1—2 years) contracts. Source: Illinois Department of Agriculture. of fruit (primarily peaches and apples) has also declined moderately during the 1980s (data for fruit and vegetable production from the U.S. Department of Commerce, Bureau of the Census). Although 50% of the state’s land is used to produce corn and soybeans, which are primarily used for livestock feed, the number of cattle and hogs has declined over the past 30 years (Figures 18-20). These trends have been followed by decreases in the amount of farmland and woodland grazed (Figures 21 and 22). Livestock production is highest in western and north- western counties. Trends in Pesticide Use Chemical pollution on farmland results from applica- tions of pesticides (primarily herbicides and insecti- cides). Unlike a point-specific source of pollution, such as an industrial smokestack, agricultural pollution originates over multiple fields and farms when agrichemicals and topsoil move off the site of applica- tion through air and water. Such nonpoint-source pollution has become a serious problem over the past few decades—both on farmland and in other terrestrial and aquatic environments. Use of such chemical compounds has increased dramatically since World War II. However, the active [|] 55 6 to 100 EEA 101 to 200 FBR «GE 201 Figure 6. Percent change in amount of farmland diverted from crops in Illinois counties, 1964 to 1987. Sources: U.S. Department of Commerce, Bureau of the Census; U.S. Department of Agriculture, Soil Conser- vation Service; Illinois Department of Agriculture. 71 AGRICULTURAL LANDS 4000 3500 —*e— WHEAT 3000 —— OATS S 2500 . —— HAY i=) ~ 2000 ‘ e HA g = 1500 genet bee aha’ oe ‘a a < J y Lister 1000 o- J \ 500 0 45 50 55 60 65 70 75 80 85 90 Figure 7. Number of acres planted in wheat, oats, and hay in Illinois in recent years. Source: Illinois Department of Agriculture. CORN SOYBEANS ACRES (1000s) ON (=) fa) fa) 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 Figure 8. Number of acres planted in corn and soybeans in Illinois, 1945-1990. Source: Illinois Department of Agriculture. 72 Figure 9. Percent increase in acres of soybeans in Illinois counties, 1964 to 1987. Source: U.S. Depart- 101-150 ment of Commerce, Bureau of the Census. Figure 10. Percent change in acres of corn in Illinois counties, 1964 to 1987. Source: U.S. Department of oo Basics SARA OF LR Commerce, Bureau of the Census. AGRICULTURAL LANDS ____ ingredients in herbicides and insecticides have changed over time. Insecticides that are widely used today tend to be acutely toxic to nontarget invertebrates and vertebrates for a few days, with toxicity declining sharply thereafter. This limited time window for acute toxicity is a major improvement compared to insecti- cides such as DDT and other chlorinated hydrocarbons that were once widely used. Compounds such as DDT, and their metabolites, persisted for decades; they pervaded the ecosystems of Illinois and were magnified in natural food chains. The demise of populations of top predators such as the bald eagle was directly related to such chemical compounds used extensively in agriculture. Because field corn has several serious weeds and insect pests (€.g., corn rootworm) and because corn occupies so much of Illinois cropland, it receives the greatest amount of pesticides compared to other crops. How- ever, on a per acre basis, fruit and vegetable crops typically are treated with much greater amounts of pesticides than corn. Figure 23 presents the estimated trends in corn pesticide use since 1945 from a variety of U.S. government sources of information. Herbicide use in corn has increased dramatically since 1964 301-400 GE 401 NO DATA Figure 11. Percent change in acres of oats in Illinois counties, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. 74 AGRICULTURAL LANDS LE -51 -50 to -6 ESSS] -5 ot 5 cesses G E 6 Figure 12. Percent change in acres of hay in Illinois Figure 13. Percent change in acres of wheat in Illinois counties, 1964 to 1987. Source: U.S. Department of counties, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. Commerce, Bureau of the Census. 100 90 80 70 60 50 40 30 ; i a | F ll ; " : TAH 0 | i AR RR RR RE 1945 1950 1955 1960 1965 1970 1975 1980 Figure 14. Percentage of cropland tilled in the fall in Illinois in recent decades. Source: Illinois Department of Agriculture. % Figure 15. Percentage of cropland for which no-till planting methods were applied in 1987. Source: U.S. Department of Agriculture, Soil Conservation Service. (Figure 24). Since 1985, over 96% of the corn and soybean acreage receives at least one application of herbicide (Pike et al. 1991). In the United States, herbicides now constitute 90% by weight of all pesticides used in agriculture (National Research Council 1989), Data from the U.S. Department of Agriculture (Figures 23 and 25) show that the acreage treated with at least one insecticide for any insect pest rose to over 40% in the late 1980s and never exceeded 60%. Nevertheless, data collected by University of Illinois researchers and presented in Table 1 show a different trend for soil insecticides, which typically dominate corn insecticide treatments. In the late 1960s, 70% of corn in Illinois was treated with a soil insecticide. The percentage is now under 30% in the 1990s, due to educational and insect monitoring programs. In addition, the dosages of chemicals applied per acre decreased during the 1980s (National Research Council 1989). Almost all previous surveys described only the amount of land treated with pesticide applications. The amount of farmland treated with various chemicals is only a crude measure of chemical disturbance. The biochemi- cal properties of such compounds and the amounts of active ingredient applied are of critical importance. The Figure 16. Percentage of cropland for which conserva- tion tillage was applied in 1987. Source: U.S. Depart- ment of Agriculture, Soil Conservation Service. Figure 17. Percentage of farmland with highly erodible soils. Source: U.S. Department of Agriculture, Soil Conservation Service. AGRICULTURAL LANDS ____ 75 AGRICULTURAL LANDS HEAD (1000s) 1946 =1951 1956 =: 1961 1971 1976 =. 1981 1986 Figure 18. Number of cattle and hogs on Illinois farms, 1945-1990. Source: Illinois Department of Agriculture. aii x ‘ ~ LE -51 wa -50 to -6 PRE") 36 to's Hie] 6 to 50 PRE «GE 51 Figure 19. Percent change in the number of cattle in Illinois counties, 1964 to 1987. Source: U.S. Depart- ment of Commerce, Bureau of the Census. 76 Figure 20. Percent change in the number of hogs in Illinois counties, 1964 to 1987. Source: U.S. Depart- ment of Commerce, Bureau of the Census. Se] 34-66 GE 67 Figure 21. Percent decrease in farmland grazed, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. amounts of active ingredients applied in corn and soybeans (Ib/acre) have been decreasing since the late 1970s (National Research Council 1989). Knowing how much active ingredient is applied per treatment per acre and how many treatments and acres are involved is critical to understanding contamination by pesticides. Unfortunately, this information is not currently available for Illinois farmland. In general, the toxicity of pesticides and their metabo- lites to nontarget organisms, and indirect effects, remain poorly understood. A plethora of compounds are used, and the list of approved compounds continues to increase. Trends in Nitrogen and Soils Illinois has the best soils for crop production in the world. However, because of soil type and slope of the land, many farms have highly erodible soils (Figure 17). Erosion by wind or water runoff moves soil around the same farm, from farm to farm, and from AGRICULTURAL LANDS ____ LE 33 34-66 GE 67 Figure 22. Percent decrease in woodland grazed, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. farm to streams and lakes. Sedimentation of water resources is a major problem in Illinois (see chapter in this volume on lakes and impoundments). At present, Illinois has one of the highest rates of inorganic fertilizer application in the Midwest. Since 1982, nitrogen, phosphorus, and potassium fertilizer use has been approximately 150, 80, and 80 pounds per acre, respectively, in Illinois, according to the Illinois Department of Agriculture. Field corn receives the vast majority of the nitrogen fertilizer. Figure 26 shows how fertilizer use has changed over the past 30 years in the counties of Illinois. Extensive use of inorganic fertiliz- ers has led to serious nonpoint-source pollution of water resources in Illinois (see volume 2 of this report). Because nitrogen is water-soluble, the potential for runoff of this nutrient is very high. Biological, chemical, and physical processes associated with agriculture have a profound effect on nutrient cycling in soils. Compared to nutrient cycles in natural ecosystems, the physical and chemical processes associated with current intensive row cropping systems 77 _______ AGRICULTURAL LANDS 100 HERBICIDE Ge est oe? -_- 70 of 60 4 = 40 - INSECTICIDE 1945 1950 1955 1960 1965 1970 1975 | 1980 1985 Figure 23. Estimated percentage of corn acreage receiving pesticide applications in Illinois, 1945-1985. The curves were drawn to fit data collected in 1952, 1958, 1966, 1971, 1976, and 1985. Source: U.S. Department of Agriculture. render soils relatively vulnerable to loss of mineral nutrients such as nitrogen through soil erosion, volatilization, and mineral leaching. Soil organic matter has been extensively depleted through acceler- ated decomposition and harvesting of chemicals with removal of crop in the annually cropped soils of Illinois. Soil depletion has led to reliance on inorganic fertilizers because of the reduced capacity of soils to accumulate and store nutrients and the high demand for nitrogen and other nutrients by crops such as corn. See Volume 2 of this report (the volume on water resources) for information on the effects of movements of inorganic nutrients relative to open water, well water, and municipal water supplies in Illinois. Trends in Wildlife and Habitats Agriculture has been the dominant influence on the flora, fauna, and quality of terrestrial and aquatic habitats in Illinois since the early 1800s. Ironically, the influence of agriculture on biodiversity in recent decades is not well documented. At present, 356 species of plants and 144 animals are considered threatened or endangered in Illinois. Many of these species are presently documented on natural areas or in other habitats that are not farmed (see chapters in this volume on forests, wetlands, and prairies). Agriculture 201-300 GE 301 Figure 24. Percent change in number of acres of farmland receiving herbicide, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. 78 6 to 100 101-200 201-300 GE 301 Figure 25. Percent change in number of acres of farmland receiving insecticides, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. AGRICULTURAL LANDS ____ 26 to 50 GE 51 Figure 26. Percent change in number of acres of farm- land receiving commercial fertilizer, 1964 to 1987. Source: U.S. Department of Commerce, Bureau of the Census. Table 1. Percentage of corn acreage treated with soil insecticide in Illinois, 1969-1990. Source 1969 1972 1976 Kuhlman et al. 1989 70 60 56 Pike et al. 1991 z 13 ke 1978 1982 1985 1988 1990 65 53 42 32 - 64 47 42 30 29 may affect the survival of threatened and endangered species through habitat destruction, alteration of the physical and chemical properties of streams, and the fragmentation of wooded and grassland tracts. More- over, where natural areas hosting rare species are bordered by agricultural environments, the flora and fauna are potentially subject to farming disturbances in the surrounding land mosaic. The status of threatened and endangered species on agricultural lands is for the most part unknown. In addition, the potential impact of agriculture on the remaining threatened and endangered species in the coming decade has not been assessed. Declines in the abundance of upland game since the 1960s (Figure 27) are a case study of how intensive agriculture has negatively affected habitat for many wildlife species traditionally common to the farm landscapes of Illinois. The declines in upland game populations and other farmland wildlife associated with habitat loss are due to expanded row crop production and the reduction in the amount of oats, perennial vegetation such as hay, and uncropped farmland, including wetlands, savannas, and permanent pasture. Farm programs diverting cropland from production were important for establishing upland wildlife habitat during the 1950s and 1960s. The Conservation Reserve Program of the 1980s has also provided wildlife habitat. However, millions of acres of cropland diverted from production under annual contract during ________ AGRICULTURAL LANDS the 1980s were poorly managed, with minimal benefits to wildlife and soil conservation (R. Warner, Illinois Natural History Survey, unpublished data). Although most upland wildlife species once common in agricultural settings have sharply declined over the past two or three decades (Figure 27), there are notable exceptions. Some species have adapted to the changes in farm practices. For example, white-tailed deer, although associated with woodland, use cropland for many life-sustaining activities. Numbers of deer have increased dramatically in recent decades, to the point that this species is a major game animal and in some areas has become a pest (see chapter in this volume on forests). The harvest of upland game such as pheasant, rabbit, and quail has been declining in recent decades (Figure 27), reflecting the declining abundance of such wildlife on farmland. Moreover, recreation associated with such hunting has also declined over the past 20 years (Figure 27). In spite of the declines, recreation associated with upland game brings millions of dollars annually to local economies in Illinois. Many appreciative forms of wildlife-associated recreation would likely expand if wildlife were more diverse and abundant. However, the extent to which future habitat improvements on farmland can be linked with economic gains to farming communities via increased consumptive and ‘ i j | | I % : MI il RECREATIONAL DAYS (1000s) 1956 1961 1966 1971 + OL er nonconsumptive wildlife recreation is poorly under- stood. Trends in habitat quality, responses by wildlife, and recreation associated with wildlife will need to be monitored. Landscape Function Agricultural environments have several key landscape functions from the perspective of natural areas and other uncommon land forms. First, some of these natural or semi-natural areas are used for agricultural purposes and, thus, are directly affected by farm practices. Second, most unfarmed natural and semi- natural areas such as wetlands, woodlands, savannas, and grasslands persist in predominately agricultural land mosaics in Illinois. Thus, natural habitats are spatially linked by agricultural land; farmland can serve as a corridor for movement of animals and plants. Third, agricultural practices can affect flora and fauna in natural areas adjacent to agricultural lands (e.g., by the exposure of flora and fauna to pesticides). Fourth, the spatial configuration of cover types and land forms in farm mosaics affects the hydrology and movements of chemical, biological, and physical elements within and across regions. In general, these spatial dynamics are poorly understood. The importance of landscape design, and the overlay of farm practices, has not been extensively studied. 5 S 7000 6000 5000 = : 4000 & — 3000 3 | SUN + ell igre le 1000 Levattea et 0 1976 1981 1986 Figure 27. Number of pheasant, quail, and rabbits harvested by hunters in Illinois and the number of recreational days associated with hunting these species. Source: William Anderson, Illinois Department of Conservation. 80 SOURCES OF STRESS ON AGRICULTURAL LANDS Some stresses have already been identified. Tillage disturbs the soil and tends to increase soil erosion. Pesticide use can stress nontarget organisms such as beneficial insects, earthworms, and wildlife. Inputs of nitrogen fertilizer produce an imbalance of nitrogen in soils already stressed by tillage, tractor compaction, and the removal of vegetation. In the next two sections, two classes of pests will be discussed. Insects It is important to evaluate the status of insects and related arthropods because they constitute the largest group of organisms in the world, they usually are very mobile, and they often are categorized as beneficial or harmful to agriculture, forests, and human health. For example, many of the most important pests in Illinois migrated to this state over the past 30 years (Table 2). At least nine species of these insects, mites, and ticks are now established as pests, and another 13 species may become important pests in the future. An addi- tional 19 species introduced to Illinois are not expected to become pests under any circumstances (Table 2). To counteract the populations of pests in agriculture, eight species of insects have been introduced over the past 30 years to act as biological control agents. Before 1960, many biological control agents were introduced to attack the European corn borer; after 1960 most of the natural enemies were directed at alfalfa pests (Table 2). Figure 28 shows the trend in immigration of new insects into Illinois. Every five years or so at least one important pest species comes to Illinois. For example, from 1960 to 1964, the western corn rootworm and the alfalfa weevil arrived. During 1965-1969, the cereal leaf beetle invaded the state. In 1985-1989, the honey bee tracheal mite, the varroa mite (another enemy of honey bees), and the Asian tiger mosquito all moved into Illinois. Integrated pest management has been successful in using host plant resistance and biological control to suppress many of these pests, especially in agriculture. Nonetheless, chemical control is still a widely used option for economic reasons in agriculture and for public health reasons in mosquito control. Even when pest populations are managed well, the annual pressure from new generations of pests may still be significant. Two examples of important pests emphasize this point. AGRICULTURAL LANDS Table 2. Partial list of insect species new to Illinois since 1960. Established species of agricultural, medical, or veterinary importance (9 species) Oulema melanopus, cereal leaf beetle Hypera postica, alfalfa weevil Diabrotica virgifera, western corn rootworm Acarapis woodi, honeybee tracheal mite Varroa jacobsoni, varroa mite Aedes albopictus, Asian tiger mosquito Ixodes scapularis, deer tick Amblyomma americanum, lone star tick Species with potential economic or health consequences, currently with limited distribution or abundance (13 species) Lymantria dispar, gypsy moth Baris lepidii, imported crucifer weevil Nezara viridula, Southern gree stinkbug Amblyomma maculatum, Gulf Coast tick Hyadaphis tataricae, honeysuckle aphid Bemisia tabaci, sweetpotato whitefly Diatraea grandiosella, wouthwestern corn borer Periplaneta fuliginosa, smokybrown cockroach Calomycterus setarius, imported longhorned weevil Cyrtepistomus castaneus, Asiatic oak weevil Cylas formicarius elegantulus, sweetpotato weevil Grapholitha prunivora, lesser appleworm Trogoxylon prostomoides, a powder-post beetle Species with noneconomic or unknown consequences (19 species) Hexarthrum ulkei, a weevil Dermestes peruvianus, a dermestid beetle Anthrenus coloratus, a dermestid beetle Ceuthophilus seclusus, a camel cricket Sternostoma tracheacolum, a nasal mite of birds Paravespula germanica, German yellowjacket Vesap crabro germana, European giant hornet Herculia intermedialis, a pyralid moth Nalepella halourga, an eriophyid mite Rhabdophaga swainei, spruce bud midge Alphitobius laevigatus, black fungus beetle Pentamerismus taxi, a false spider mite Amblytylus nasutus, bluegrass plant bug Dolerus wanda, a sawfly Neodiprion excitans, blackheaded pine sawfly Monochamus scutellatus, whitespotted sawyer Neoclytus muricatulus, a long-horned beetle Xylotrechus sagitattus, a long-horned beetle Caloptilia azaleella, azalea leafminer Beneficial species, including those released for biological control (8 species) Bathyplectes curculionis, an alfalfa weevil parasite Microctonus anurus, an alfalfa weevil parasite Microctonus colesi, an alfalfa weevil parasite Tetrastichus incertus, an alfalfa weevil parasite Coccinella septempunctata, an aphid predator Patasson luna, an alfalfa weevil parasite Biolysia tristis, a parasite List compiled by the Illinois Natural History Survey, Center for Economic Entomology, April 1992 81 AGRICULTURAL LANDS The European corn borer has been an important pest in Illinois since it migrated to the state more than 50 years ago. The average annual loss of corn grain due to corn borer in Illinois was estimated in the 1980s at $50 million. Figure 29 shows the pattern of population fluctuations over the state since 1943. Generally, more than two corn borers remaining in a stalk during the fall sampling period represent damaging populations in Illinois corn fields. Of course, when the average for the state is near two per stalk, many fields have many more than the average. Figure 29 demonstrates that the corn borer populations have not declined during the past 10 years. The gypsy moth is a serious defoliator of urban and forest trees in the northeastern United States. In Illinois, the moths have been trapped off and on over the past 20 years, usually in very low numbers. Most have been caught in the northeast part of the state around Chicago (Figure 30). This pest may be estab- lished in this area or the traps may, be picking up male moths that have flown far away from areas infested by flightless females. The values in Figure 30 are lower than those found in the heavily infested areas in the Northeast. Based on 1992 trapping, 18 sites comprising 400 acres required treatment in 1993. =O oOo sy ec Zz =o 1960-64 1965-69 1970-74 Co —-0 OO OO 1975-79 Quinquennial periods To establish a viable population, female and male larvae must slowly enter a new region along an invasion front. The wave of infestation is currently moving through Michigan (Figure 31). This wave is expected to reach Shawnee National Forest in southern Illinois in the year 2000. A faster means of migration over long distances can occur when the gypsy moth hitches rides on motorized vehicles that have passed through infested areas. Thus, a recreational vehicle that leaves Michigan in July and travels to an Illinois forest may promote the spread of the gypsy moth. Swofford et al. (1988) predicted that almost all oak-hickory woodlands in the state will be in danger of extensive defoliation by the gypsy moth. As the chapter in this volume on forests indicates, many of the major forests in the state are oak-hickory. Thus, the invasion of the gypsy moth should be considered a major development. Weeds The control of weeds has been a major concern for agriculture for over a century. Because weeds are an economic threat to crops, farmers use chemical and mechanical means to control them. The most important agricultural plant pests are listed in Table 3. Insect species new to Illinois since 1960 1980-84 1985-89 1990- __] Economic pests WB Minor or unimportant Figure 28. Number of insect species arriving in Illinois in five-year intervals since 1960. Source: Illinois Natural é p § J y History Survey. AGRICULTURAL LANDS Summary of Fall Surveys, a=, sc 5 wm oo 4 lu © 3 @ <— E 2 = | = o | © ae =< European Corn Borer 1943 through 1992 1944 1948 1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 Year Figure 29. Trends in the number of European com borers in Illinois, 1943-1992. Source: Illinois Natural History Survey. CONCLUSION Agriculture is the most important single industry in Illinois. With over 80% of the land area in farms, agriculture has a pervasive influence on the terrestrial and aquatic environments of the state. Agriculture and environmental quality have changed dramatically since World War II in conjunction with emerging farming practices and associated technologies. Agricultural practices have led to serious environmental problems, and these problems have generally become worse in recent decades. For example, the use of inorganic fertilizers and herbicides has increased dramatically. The extensive use of inorganic fertilizers has allowed for intensive row crop monocultures that are not efficient in terms of nutrient and energy cycling. Intolerably high soil erosion rates and water quality problems have become widespread where intensive row cropping has encroached on marginally suitable soils, and soils have been highly disturbed during tillage and planting. The expansion of row crop farming has accelerated the loss of wildlife habitat, contributing to a decline in the abundance of most wildlife species and a loss in biodiversity—trends that have become progressively worse since the early 1800s. Also, as agricultural environments have become seriously degraded, movements of soil and chemicals from farmland to NS XN) iN NAN, o 151-300 451-600 Bie GE 601 [___] NOT PRESENT Figure 30. Distribution of gypsy moths in Illinois, 1992. Values indicate number of gypsy moths trapped per county. Source: National Agricultural Pest Information System database, USDA-APHIS/PPQ. 83 —_____ AGRICULTURAL LANDS | 1900 1914 oe Figure 31. Spread of gypsy moth defoliation in the United States, 1900-199]. Source: U.S. Forest Service. 1965 1991 Table 3. Major agricultural plant pests in Illinois. underground water supplies and tributaries has led to Plants are listed in order of descending economic serious problems of siltation and chemical alterations importance for weed control efforts. in nearly all aquatic environments in the state. Velvetleaf Foxtail During the past decade, however, some significant Cocklébur progress has been made in addressing environmental Pigweed problems related to agriculture. For example, the Smartweed adoption of conservation tillage methods has become Giant ragweed Annual morning glory Common ragweed Lambsquarter Jimsonweed Hemp dogbane Milkweed (common) Black nightshade Fall panicum Shattercane Yellow nutsedge Canada thistle Source: Pike et al. 1991. widespread and continues to increase. There is also evidence that insecticide use has declined statewide as integrated pest management practices have been adopted. LITERATURE CITED Kuhlman, D.E., E.L. Knake, M.E. Gray, and H.W. Dirby. 1989. IPM: a systems approach to sustainability. Illinois Resource 31:15-18. National Research Council. 1989. Alternative agricul- ture. National Academy Press, Washington, D.C. 448 p. SSSSSS—S——CV'".__ ss AGRICULTURAL LANDS Pike, D.R., K.D. Glover, E.L. Knake, and D.E. Kuhlman. 1991. Pesticide use in Illinois: results of a 1990 survey of major crops. Publication DP-91- 1. University of Illinois College of Agriculture, Cooperative Extension Service, Urbana. Swofford, D.L., M.R. Jeffords, and K.W. O’Hayer. 1988. Predicting the susceptibility of Illinois forest stands to defoliation by the gypsy moth. Illinois Natural History Survey Biological Notes 131. 4 p. NOTES ON SOURCES OF INFORMATION FOR FIGURES Illinois Department of Agriculture: Published and unpublished data regarding farming in Illinois were obtained from the Illinois Department of Agriculture, Springfield. For example, annual trends in crop production are published in reports such as JIlinois Agricultural Statistics: Field Crops by Counties, 1975- 1987 (Illinois Department of Agriculture Bulletin 90- 2). Annual trends in livestock production are published in reports such as Illinois Agricultural Statististics: Livestock and Poultry by Counties, 1975—1988 (Illinois Department of Agriculture Bulletin 90-3). U.S. Department of Agriculture, Soil Conservation Service: State and national data were acquired from Stephen J. Brady, Soil Conservation Service/Forest Service, Rocky Mountain Forest and Range Experi- ment Station, 3825 E. Mulberry, Ft. Collins, CO 80524-2098 and from Richard Dickerson, Soil Conser- vation Service, 1902 Fox Drive, Champaign, IL 61820. U.S. Department of Commerce, Bureau of the Census: The Bureau of the Census is the source of census of agriculture data. For example, the 1987 data are published in U.S. Department of Commerce. 1989. Vol. 1. Geographic area series. Part 51. United States summary and state data. AC87-a-51. Bureau of the Census, Washington, D.C. 414 p. The data and supporting documents can be obtained from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 85 ee) ee ; aa oe Tapnd & Maye agrteniinica) pac) Pests tA Ti Geis, versano tive a | Viera tre listed Sy under af dépceading coon mone OD RAL SH | wiper ee>sitaa coin eNeNEH ay ney al li Fesxinaide ht saat") nd io ant > seit [oo tratemandciecadag iin ip . nee ; pre : Be be ri Ht CV Ate , ' Verret iT y" My weed oPpanet eles Chun aaweld Annual one wh? giory Counties fe juve Larsbeayastae Neowonw chal Hoong ckyeheune Nitikweed (corti) CO a ae ‘ Deby, RD NON ) iy wasn len puutaaqstnt! ers oy Hh seit ayes Cally i ey wy Pye 4 / ae we te et ty ha AS i wr hdr ae 4t i , L en salle Pillag 4 whe AD ‘ : ITER AVON ona er. ' agvets om @)\ ‘ ae Bei de rae ay. ilies air: WETLANDS SUMMARY Wetlands in Illinois and elsewhere have tremendous biological value. They provide essential habitat to a wide variety of flora and fauna; they can be effective nutrient and sediment traps; they can modify flood waters; and they are sources for groundwater recharge and discharge. Wetlands also provide a multitude of substantial economic benefits, including recreation and improved water quality. Although wetlands are an important and productive ecosystem and are becoming increasingly appreciated, little information, other than descriptive information, on Illinois wetlands is avail- able to document trends in their numbers as well as trends in their plants and animals. Less than 50% of the presettlement wetlands in the lower 48 states exist today. Primarily because of drainage for agricultural purposes, only 917,765 acres (371,414 ha) of natural wetlands remained in Illinois by the 1980s, or about 10% of an incomplete estimate of 9.4 million acres (3.8 million ha) of original wet- lands. Only approximately 6,000 acres (2,429 ha) of the wetlands remaining in Illinois were high quality and undisturbed. Thus, Illinois has lost at least 90% of its presettlement wetlands, and this loss occurred at an estimated rate of 0.5 to 1.0% per year from the mid- 1950s to the mid-1970s. The remaining natural wetlands occupied about 2.6% of Illinois in the 1980s. Furthermore, many of the remaining natural wetlands have been severely reduced in quality because of sedimentation, pollution, or other impacts of modern society. Existing wetlands, including both natural and modified wetlands, occupied 1,253,891 acres (507,443 ha) of Illinois in the 1980s, or about 3.5% of the state. Palustrine wetlands represented 93% of Illinois wetlands in the mid-1980s. Relatively undisturbed remnants of the rare wetland communities of seeps, pannes, bogs, and fens were represented by less than 350 acres (142 ha) each. Wetland plants compose about 32% (952 of 2,959 species) of the total flora (both native and non-native) of Illinois and 42% (862 of 2,069 species) of the native flora of the state. Additionally, more than 18% of the native wetland plant species in Illinois are listed as threatened or endangered. Approximately 35 wetland plant species appear to have become extirpated from the state. About 9.4% of the wetland flora of Illinois consists of non- native species. Most of the birds, mammals, amphibians, and reptiles in Illinois use wetlands. As many as 266 species of birds can use wetlands in Illinois during some stage of their life cycle. The numbers of nesting colonies of great blue herons and great egrets have increased since 1983. The numbers of great blue herons, great egrets, and black-crowned night herons have also increased in the state since 1983. Unfortunately, the numbers of many species of ducks migrating through Illinois have been decreasing over the past 40 years; the decreases are a result of lower continental numbers of many of these species and the degradation and the loss of wetlands and, consequently, the waterfowl food provided by wetlands in the state. Thirty of the 43 species of endangered and threatened birds in Illinois are strongly associated with wetlands. Numbers of endangered double-crested cormorants and bald eagles in Illinois have steadily increased since the federal prohibition of certain pesticides in the 1970s. In addition to over 2,000 bald eagles observed wintering in Illinois in 1992, there were 17 nests from which 16 eaglets successfully fledged. Of the 59 species of mammals in Illinois, at least 36 use wetland habitats. Eight of the 10 endangered and threatened mammal species in Illinois depend upon wetlands. Thirty-seven of the 41 species of amphibians in Illinois use wetlands, and all three species of amphibians that are listed as endangered or threatened in Illinois depend upon wetlands. Of the 60 species of reptiles in Illinois, at least 47 utilize wetlands. Seven of nine species of reptiles listed as endangered or threat- ened in Illinois use wetlands. Twelve of the 29 endan- gered and threatened fish species in Illinois occur in wetlands or use them for spawning. Overall, of the 94 species of vertebrates listed as threatened or endan- gered in Illinois, and 64% utilize wetlands, at least for some part of their life. The current abundance and distribution of many wetland plants and animals is only a remnant of what the European explorers and early settlers experienced. Unfortunately, the trends in the populations of many 87 88 WETLANDS animals that depend on wetlands are not definable because of inadequate baseline or long-term data. Several federal and state governmental programs are available to reduce continuing wetland loss and degradation. Nonetheless, a consistent, enforceable national protection policy for wetlands is necessary. Other needs include the determination of economic values for the functions of wetlands, the development of methods to assess the results of wetland restoration and creation projects, and the actual evaluation of the outcomes of specific projects. The mitigation of wetland loss through restoration and creation has generated much interest, but few studies have docu- mented the success of created or restored wetlands. Thus far, many wetland creation projects have fallen short of equaling the benefits that natural, high-quality wetlands provide. The citizens of Illinois and the nation are becoming more aware of the value and importance of their wetland heritage. Knowledge, understanding, and appreciation of wetland systems and their importance must be expanded, more widely disseminated among the general public, and increasingly incorporated into our public policies to insure that this critical ecosystem remains a vital part of our state’s natural heritage. INTRODUCTION Wetlands are among the most important ecosystems on our planet (Figure 1). Approximately 6% of the land surface of the earth is wetland (Mitsch and Gosselink 1986). Wetlands are generally defined as lands where water saturation is the dominant factor that determines both soil development and the types of plant and animal communities living in the soil as well as on its surface (Wilen and Frayer 1990). Therefore, wetlands are transitional lands between terrestrial and aquatic systems where the land is covered by shallow water or the water table is at or near the surface. Unfortunately, from colonial times until the past two decades, “wetlands have been regarded as nuisances, wastelands, habitats for pests, and threats to public health” (Wilen and Frayer 1990:182). Consequently, they have been “reclaimed” by draining, clearing, and filling in the name of progress. In recent years, how- ever, wetlands have become more appreciated for their functions as well as for their economic values. The functions of wetlands include regulating the flow of water, storing water, recharging groundwater, filtering and purifying water, trapping sediments, providing Figure 1. Wetlands, such as this marsh in Tazewell County, are productive and important ecosystems. habitat for plants and animals, and providing recre- ational opportunities (Wilen and Frayer 1990). Wet- lands have been described as “the kidneys of the landscape” for some of the functions they perform in cleansing our environment (Mitsch and Gosselink 1986). Wetlands are an important part of our nation’s heritage, and they provide benefits for all citizens (Feierabend and Zelazny 1987). Forty-five percent of federally listed threatened and endangered animal species and 26% of the listed plants depend upon wetlands during their life cycle. Additionally, 5,000 species of plants, 190 species of amphibians, and 270 species of birds are estimated to inhabit our nation’s wetlands (Feierabend and Zelazny 1987). Approximately 75% of the bird species in North America depend upon wetlands for resting, feeding, or nesting (Steinhart 1990). One of the more recognizable characteristics of a wetland is that it is continually changing. Water levels may fluctuate daily, seasonally, annually, or over several years. The high degree of biological productiy- ity of wetlands is a result of their dynamic and transi- tional water levels (Feierabend and Zelazny 1987). Many of the plant and animal species associated with wetlands are adapted to this fluctuating environment. Nevertheless, the quantity and the quality of wetlands are sensitive to human perturbations, and our activities have greatly affected these productive systems (Feierabend and Zelazny 1987). By the mid-1980s, approximately 103.3 million acres (41.8 million ha) of the estimated 221 million acres (89.5 million ha), or about 47%, of wetlands present at the time of colonial America remained in the contermi- nous United States (Dahl and Johnson 1991). The remaining wetlands occupy approximately 5% of the land area. Prior to recent legislation, wetlands had been destroyed nationally at a rate of about 1% per year (Mitsch and Gosselink 1986). Ten states, including Illinois, have lost 70% or more of their original wetland acreage (Dahl 1990). This component of the critical trends report examines wetlands and their associated flora and fauna in Illinois. Unfortunately, the data necessary to analyze trends for these resources are limited. Much of the relevant information is restricted to a relatively short period of time; in many cases data exist for only a single point in time, thereby making reliable determi- nations of trends difficult or impossible. However, existing data, much of which is descriptive, will provide valuable baseline information for future analyses and investigations of wetlands. DEFINITION OF WETLANDS Wetlands are natural communities located along the hydrological gradient between terrestrial (land) and aquatic (water) habitats. Water, or hydrology, is the dominant force that creates and maintains wetlands. Typical wetlands include marshes, swamps, ponds, potholes, bogs, sloughs, wet meadows, mudflats, and river overflows. Some federal agencies currently use the 1987 wetlands delineation as the official means to identify wetlands. In general, wetlands exhibit the following characteristics: 1. The water table (the upper limit of that portion of the ground that is entirely saturated with water) remains at or near the surface, and water covers the land at least part of the year. 2. The soils are hydric (wet for most of the year and low in oxygen). 3. The plants that grow there are adapted to life in water or saturated soil (hydrophytes). FUNCTIONS AND VALUES OF WETLANDS Wetlands, like any natural habitat, have an aesthetic quality and interest that merit their preservation, but they also serve us in ways that are essential. Wetlands play a unique and irreplaceable role in maintaining the quality of our water, in controlling floods, and in providing habitat for an incredible diversity of species. Important wetland functions are summarized in Table 1. Wetland value is an interpretation of the relative worth of a wetland function, and the value can be positive or WETLANDS negative (Feierabend and Zelazny 1987). Wetlands possess substantial economic values. Farber and Costanza (1987) estimated that, depending upon the methodology used, the total social value of wetland ecosystems ranged from $590 to $10,000 per acre. Feierabend and Zelazny (1987) reported that a wetland with an active water-flow regime, such as a seasonally flooded bottomland forest, could have a value of $30,000 per acre or more based upon a holistic method of analysis. The estimated social value of annual benefits expressed as capital value in Massachusetts in 1972 was $59,900 per acre of wetlands, with high levels of benefit related to wildlife, aesthetic value, water supply, and flood control (Gupta and Foster 1975). The value of the harvest of furbearers in wetlands during the 1974-1975 season exceeded $35 million in the United States (Chabreck 1978). In 1975, recre- ational fishermen spent $13.1 billion on fishing activities directed toward wetland-associated fishes (Peters et al. 1978). The U.S. Fish and Wildlife Service (USFWS) estimated that 1.9 million waterfowl hunters spent $307 million in 1980 (Feierabend and Zelazny 1987). A recent survey by the USFWS found that more than half of the adult population in the United States participated in a recreational activity related to fish and wildlife during 1991 (Illinois Department of Conserva- tion 1993). According to the survey, more than 98 million Americans age 16 and older contributed $59.5 billion into our nation’s economy in 1991 as a result of these activities. Fishing was a favorite pastime, with 34.8 million anglers 16 years and older spending an estimated $25.3 billion, or $700 each, in 1991 for fishing-related activities. There were almost 14 million Americans 16 and older who hunted, thereby contribut- ing about $12.3 billion, or $900 each, to the 1991 economy. More than 76 million American adults engaged in nonconsumptive wildlife-related activities, such as observing and photographing wildlife; noncon- sumptive users spent an estimated $7.5 billion on related travel costs, $9.6 billion for equipment, and $1 billion on dues, contributions to wildlife-related organizations, magazines, or other expenses. In Illinois, the total annual economic impact was recently estimated to be $1.6 billion from fishing and $366 million for hunting, whereas annual nonconsumptive expenditures were estimated to be $893 million (Conlin 1991). The total annual expendi- tures for fishing, hunting and nonconsumptive recre- ation in Illinois averaged $2.86 billion in the late 1980s. The average annual harvest of waterfowl in Illinois and the Mississippi Flyway from 1986 to 1990 89 —______. WETLANDS Table 1. The important functions of wetlands. Function Description Flood conveyance Wetlands associated with riverine systems serve as floodways transporting flood pulses from upstream to down- stream locations. Wetlands act as reservoirs, slowing water runoff rates and thereby decreasing erosion. Wetlands associated with lakes and rivers buffer waves, protecting uplands and shorelines. The accumulation of organic material and detritus over long periods of time forms peat, which gradually fills the wetland basin. By definition, wetlands eventually progress into terrestrial forests. This process is known as autogenic succession. Inland wetlands store flood waters and slowly deliver water to downstream areas. Floodplain wetlands act on riverine systems by lessening flood peaks. Vegetation in floodplain wetlands reduces flood velocity, causing sedimentation of particles in flood waters. Wetlands act as nutrient sinks and settling ponds by removing excess nutrients, chemicals, and particulate matter from runoff and flood waters. Wetland vegetation utilizes excess nutrients for plant growth, and chemi- cals become entrapped and break down in sediment. Some inland marshes are now being used as tertiary waste (sewage) treatment facilities. Wetlands supply water for human consumption, agricultural irrigation, and industrial processes. Some wetlands store and then slowly release water, recharging groundwater deposits. Wetlands provide food, cover, loafing, and nesting habitat for a wide array of wildlife species while harboring a large assortment of plant species. Wetlands are home to about one-third of all plant and animal species recognized as threatened or endangered. Wetlands offer many recreational opportunities, such as hunting, fishing, boating, swimming, and wildlife photography. Wetlands provide opportunity for environmental education and scientific research, providing people a better understanding of organisms and their environment. Erosion control Wave barriers Land formation Flood storage Sediment control Pollution control Water supply Aquifer recharge Habitat Recreation Education and research Food production The highly productive nature of wetlands makes them a source of food production from marsh vegetation and aquaculture and annual fish and waterfowl harvests. Timber production Forested wetlands under proper manage- ment are an important source of lumber. Lumber produced from the common baldcypress is highly valued. Wetlands have been valued as high as $60,000 per acre ($24,000 per ha) on a multiple-use basis. The 32 million acres (13 million ha) of bottomland hardwoods and common baldcypress swamps of the southeastern United States are worth approximately $8 billion in timber production. Many people believe the aesthetic values of wetlands are the most important. Wetlands are beautiful and offer seclusion and tranquility. Wetlands provide observers a vast array of plant and animal life. Economic Aesthetic was estimated by the USFWS to be 193,500 and 2,942,500, respectively, for ducks and 74,464 and 437,567, respectively, for geese (Havera 1992). The estimated expenditure of Illinois waterfowl hunters during the 1990-1991 hunting season was $44 million, or an average of $743 per hunter (Anderson 1991). The economics of the Canada goose resource in Illinois is important, and it is a multi-million dollar industry in southern Illinois. Indeed, each goose was estimated to represent about $10 to the local economy in southern Illinois (Thomas 1990). During the 1990-1991 season, goose hunting generated an estimated $9.5 million in the Southern Quota Zone of Illinois, about $3.0 million in the Rend Lake area, and approximately $2.5 million in the Tri-County Zone in west-central Illinois (Ander- son 1991). Furthermore, economists estimate that each dollar spent turns over 1.5—2.5 times within a commu- nity (Thomas 1990). Canada geese also provide an important nonconsump- tive recreation resource. In the mid-1970s, more than 150,000 visitors visited the Horseshoe Lake Refuge in Alexander County each year to enjoy the flocks of wintering Canada geese (Kennedy and Lewis 1977). Personnel at Crab Orchard National Wildlife Refuge have estimated that 275-300 people frequent their observation towers each day to view Canada geese (Thomas 1990). Heinrich and Craven (1992) estimated that about $3.7 million in gross revenue was derived in 1986 from Canada goose viewers and hunters in the Horicon Marsh area of Wisconsin. Although it is difficult to assign a dollar value to the human experience and enjoyment of a day afield, the economic benefits of wetlands used as aesthetic retreats and for nature study are likely comparable to those derived from commercial uses of wetlands (Feierabend and Zelazny 1987). DESCRIPTION AND CLASSIFICATION OF WETLANDS Wetlands can be classified into a variety of forms, each with its own special profile. Swamps (Figure 2) and marshes are perhaps the most familiar. Illinois alone has many different wetland habitats that vary in climate, water supply, soil type, and plant and animal residents. Wetlands range from those in which the soil is saturated for at least part of the year to those with permanently standing water, from wetlands associated with the seasonal changes that occur along a river to those that were formed directly or indirectly by the action of ancient glaciers, from wetlands characterized by organic soils (soils made primarily from decayed plants) to those in which inorganic (mineral) soils predominate, and from grassy wetlands to those that are forested. No two wetlands are alike, and each is an important ecosystem with influence far beyond its perimeters. In much of the Midwest, wetlands were formed either by the action of glaciers or by rivers. During the last Ice Age, before the retreat of Wisconsinan glaciation about 15,000 years ago, large blocks of ice remnant from the main glacier body melted and formed lakes. In other areas, glaciers merely scooped out shallow depressions that allowed water to accumulate as the ice retreated. Glacial melt-water torrents such as the Kankakee Torrent deposited deep sands locally in the major river valleys in the northern half of Illinois, and these sand deposits support distinctive wetlands. Wetlands formed by rivers are of several types, including oxbow marshes, floodplain bottomlands, and backwater lakes. When a meandering river changes course and leaves a portion of its channel isolated except during flood, an oxbow pond is formed. In time, this pond fills in and becomes an oxbow marsh. Floodplain bottom- lands are created by periodic flooding and include bottomland forest, swamp, and marsh habitats. Backwa- ter (bottomland) lakes form when soil and sand settle out of river currents and form long islands in the river. If such an island becomes high enough to completely separate the side channel from the main river, a bottom- land lake is formed. In addition, human activities create as well as destroy wetlands, and some wetlands are WETLANDS produced by impoundments, excavations, and the construction of dikes. The types of plants and animals found in oxbow marshes and backwater lakes are determined largely by the periodic flooding of these areas by the main river. Because this annual flood is a predictable and recurring phenomenon, many organisms have evolved adapta- tions that enable them to exploit the seasonally expanded habitat and .the food brought in by the flood. Times of low water, however, are just as important as flooding. A low water level concentrates fish into shallow pools where herons and egrets obtain food for nestlings; it exposes mudflats where moist-soil plants grow and produce seeds sought by waterfowl; and it allows soils to drain and be exposed to oxygen, thereby speeding the processes of decay and the recycling of nutrients. Midwestern wetlands can have either mineral (inor- ganic) or organic soils. Mineral soils are composed largely of sand, silt, or clay. Organic soils, generally called peat or muck, are formed from plant material that has partially decayed in wet ground that is low in oxygen (anaerobic). These soils are low in oxygen because standing water has partially insulated the plant material from the atmosphere. Hydrology, the way water is distributed on or below the earth’s surface, is important in classifying wetlands. In general, wetlands have two sources of water: surface water from precipitation (rain, snow, ice) and ground- water (the water found below the surface of the soil). A depression that is deep enough to extend below the water table forms a wetland fed by both groundwater Figure 2. Cypress swamp is an important wetland habitat in the floodplain of the Cache River in Southern Illinois. 91 92 _____ WETLANDS and surface water. A depression that does not extend below the water table receives only surface water, such as precipitation and runoff from the surrounding land. Wetlands found on slopes, usually surrounding a lake, pond, or stream, may receive water from several sources, including runoff, floodwater, and groundwa- ter. The length of time the area remains saturated depends on the degree of slope, soil characteristics, and the frequency of flooding or runoff from precipitation. Contemporary wetlands, particularly undisturbed remnants, provide our best measure of the composition, structure, and dynamics that characterized the original wetlands of Illinois. Wetland dynamics can sometimes only be appreciated with long-term monitoring of the vegetation and hydrology. Such data are generally not available for most wetland community types. One example of the dynamic nature of certain wetland types can be observed from photographs taken of a natural sand pond in Iroquois County (Figure 3) from approxi- mately the same location, on approximately the same date, during 1987 and 1988 (a severe drought year). This sand pond was characterized in 1987 by standing water and populations of pickerelweed (uncommon in Illinois), spatterdock, an uncommon species of bur- reed, and other emergent wetland species. However, during the severe drought of 1988, no standing water was present and the vegetation composition completely changed. Manna grass, absent in 1987, was the dominant species filling the pond basin in 1988. By 1992, bluejoint grass was the common species, and pickerelweed and spatterdock were present again but did not reach full development until much later during the growing season. The wetlands of Illinois were inventoried in the 1980s as part of the National Wetlands Inventory (NWI) program, a nationwide effort by the USFWS to locate and classify wetland and deepwater habitats. The NWI defines wetlands as areas that are periodically saturated or covered with water less than 6.6 feet (2 m) deep; they must have one or more of the following attributes: hydrophytic vegetation, hydric soils, and saturated hydric conditions or with shallow water inundation at some time during the growing season. The NWI uses the classification system developed by Cowardin et al. (1979). The NWI was modified and enhanced into the Illinois Wetland Inventory (IWI) to more accurately describe the wetlands of the state (Table 2). The IWI was a joint effort of the Illinois Department of Conservation (IDOC), the Illinois Natural History Survey (INHS), and the USFWS. This computerized geographic database stores spatial or map data (i.e., the location and shape of wetland and deepwater habitats) and descriptive information about each map feature. Every wetland and deepwater feature in the [WI is described by area and perimeter, an NWI code describing the ecological and physical characteristics of the feature, and an Illinois Classification code, which is an alter- nate description based on the NWI codes. The Illinois Classification code facilitates use of the data and was used for Illinois wetlands for the present report. The Illinois Classification code distinguishes between wetlands and deepwater habitats that are “natural” (i.e., not diked, impounded, dug, or channelized) and those modified or created by human activity (i.e., diked, impounded, dug, or channelized). “Natural” wetlands represent the original or naturally occurring wetlands in the state. The NWI/IW1 is the only existing comprehensive inventory of the wetland resource of Illinois. A recently Figure 3. Sand Pool in Iroquois County photographed from near the same location about 1 July during 1987 (top) and 1988 (bottom). Changes reflect the dynamic nature of certain wetland types. completed analysis of the present (1980-1987) status of wetlands (Suloway et al. 1992) is the basis for much of the information presented here on Illinois wetlands . WETLANDS IN ILLINOIS During the 1980s, 917,765 acres (371,414 ha) of natural wetlands (2.6% of the total land) were identi- fied in Illinois using the IWI classification (Table 3). Natural wetlands were concentrated in northeastern Illinois and along the rivers in southern Illinois, such as the Kaskaskia, Big Muddy, Little Wabash, Cache and Mississippi (Figure 4). All existing wetlands, including those modified or created by dike, impoundment, digging, or channelization, occupied 1,253,891 acres (507,443 ha), or 3.5% of the state (Figure 5, Table 3). These wetlands are divided into three main categories: palustrine, lacustrine, and riverine. Palustrine Wetlands Palustrine wetlands are dominated by vegetation or, if lacking vegetation, they are small and shallow (< 20 acres and < 6.6 feet deep). Wetlands commonly known as marshes, bogs, fens, sedge meadows, wet prairies, swamps, bottomland forest, and ponds fall into this category. In Illinois, 93% of the existing wetlands, including both natural and modified or created wetlands, Table 2. Categories of wetland communities, based on the Illinois Wetlands Inventory (IWI) classification. Some rare wetland types are not identified in WI, and their identification is based upon the Illinois Natural Areas Inventory (INAI). IWI classification Palustrine Forested Bottomland forest Swamp Emergent Shallow marsh/wet meadow Deep marsh Open water Scrub-shrub Lacustrine Riverine Rare types (INAI) Bogs Fens Seeps and springs Pannes WETLANDS are palustrine. Four types of palustrine wetlands occur in Illinois: forested, emergent, open water, and scrub-shrub. Forested wetlands, particularly bottomland forest, are by far the most abundant group, representing 60% of the state’s total wetlands (and 71% of natural wetlands) (Figure 6). Emergent (shallow marsh/wet meadow and deep marsh) wetlands are the next most abundant (16%), followed by open water (11%), and scrub-shrub (4%) wetlands. Forested Wetlands. Forested wetlands are dominated by woody vegetation. They are differentiated into swamps or bottomland forest based on the duration of the presence of water. Forested wetlands are largely concentrated in southern Illinois, with scattered concentrations along the Illinois, Mississippi, and other rivers (Figure 7). Swamps are defined by IWI as forested areas in which the woody vegetation is 20 feet (6 m) or more in height and water is present on a permanent or semipermanent basis; the woody vegetation is adapted to prolonged exposure to standing water. HY / j ait ["] 0 - 681 f IM 682 - 1,315 %& FR 1,316 - 2,296 RE 2,297 - 3,763 WM 3,764 - 10,250 fia Figure 4. Distribution of natural wetlands by 7.5- minute quadrangle (1980-1987). Source: Suloway et al. 1992. 93 ______. WETLANDS Table 3. Amounts of various wetland types in Illinois (based on Illinois Wetlands Inventory classification; taken from Suloway et al. 1992). Percentage of Percentage of Natural Modified/artificial Habitat Acres total land total wetlands Acres Percentage Acres Percentage Palustrine wetlands 1,168,964 Ske, 932 888,155 76 280,809 24 Forested 773,632 22 61.7 661,174 85 112,458 14 Swamp 14,939 0.0 1.2 10,553 71 4,386 29 Bottomland forest 758,693 2.1 60.5 650,621 86 108,072 14 Emergent 201,621 0.6 16.1 172,178 85 29,443 15 Shallow marsh/ 162,913 0.5 13.0 146,873 90 16,040 10 wet meadow Deep marsh 38,708 0.1 oh 25,305 65 13,403 35 Open water 143,345 0.4 11.4 16,402 11 126,944 89 Scrub-shrub 50,366 0.1 4.0 38,401 76 11,964 24 Lacustrine wetlands 55,568 0.2 4.4 10,307 19 45,261 81 Shallow lake 51,868 0.1 4.1 9,354 18 42,514 82 Shore 2,929 0.0 0.2 422 14 2,507 86 Emergent 7712 0.0 0.1 531 69 240 31 Riverine wetlands 29,358 0.1 2.3 19,302 66 10,057 34 Perennial 3,967 0.0 0.3 3,802 96 164 4 Intermittent 25.392 0.1 2.0 15,500 61 9,892 39 Total wetlands 1,253,891 3:5 - 917,765 73 336,126 27 Forested swamps, once common in the southern Midwest, are often dominated by bald cypress and water tupelo. The cypresses may reach prodigious size; in Illinois, the largest is more than 34 feet (11 m) in circumference. Cypresses are also among the oldest living organisms on earth. In southern Illinois, thousand-year-old specimens can still be found. The soil in forested swamps may be either organic or mineral but usually has a topmost organic layer underlain with a mineral soil. Shrub swamps are similar to forested swamps except that less of the vegetation is in the form of trees. Typical plants include willows, Virginia willow (not a true willow), buttonbush, swamp rose, and a few species of dogwood growing in mostly mineral soils. In Illinois, the most extensive swamps are limited to iW ‘ the southern tip of the state near the northernmost [_] 0 - a0 ‘ - ij Fl ; extension for the swamp communities found in the [IM] 881 - 1,657 & ; {| as southern United States. The 14,939 acres (6,048 ha) of FRR iesa-o712 * swamp, including 10,553 acres (4,264 ha) classified as ame Aim natural, are concentrated in the Cache River basin. RE 2,713 - 4,369 HEM 4.370 - 13,488 Acres Bottomland or floodplain forests are temporarily or seasonally flooded areas that usually occur along streams and rivers (Figure 7). Because these forests are Figure 5. Distribution of total wetlands by 7.5-minute flooded frequently, they have a lower diversity of tree quadrangle (1980-1987). Source: Suloway et al. 1992. species than forests located on higher ground. The understory is typically open, and the ground cover is sometimes dominated by nettles. Rotting logs and woody debris deposited by floodwaters are abundant. Typical trees of Midwestern floodplain forests are silver maple, cottonwood, green ash, hackberry, and sycamore. Several oak species can be found on terraces bordering floodplains. The soils that support these forests are usually mineral. Bottomland forest, representing 60.5% of the wetlands in Illinois, is the largest single category of the existing wetland habitat in the state. In the mid-1980s, there were 758,693 acres (307,163 ha) (650,621 natural acres; 263,409 ha) of bottomland forests in Illinois. Concentrations of bottomland forests are found along the Illinois, Kaskaskia, Big Muddy, Cache, Little Wabash, and Mississippi rivers; much of this resource is located in the southern third of the state (Figure 7). Emergent Wetlands. Emergent wetlands are dominated by erect, rooted, herbaceous hydrophytic vegetation—for example, sedges, grasses, and numerous species of forbs. Emergent wetlands are most prevalent in northeast Illinois (Figure 8). Vegetation may remain visible throughout the year or die back in the nongrowing season. Examples include sedge meadows dominated by tussock sedge, wet prairie dominated by cord grass, and marshes. Water depth in marshes ranges from zero (saturated soil) to 6.6 feet (2 m) by NWI definition. In Midwestern marshes, both floating-leaf plants (e.g., water lily) and submerged aquatic plants (e.g., pond- weed) are frequently associated with cattails, an emer- gent species. The soils that underlie marshes are some- times mineral but are often covered by muck (organic sediment). Marshes are highly productive habitats in which hundreds of species of birds, insects, and other wildlife spend most of their lives. Productivity in any ecosys- tem is usually measured in terms of the living things that it produces (biomass). Two factors account for the high productivity of marshes. One is the ability of marsh plants to capture large amounts of energy from the sun and transform and store much of it as chemical energy in the form of plant tissue. The other is the efficient recycling of nutrients already produced, recycling accomplished as dead plants and animals decompose and become nutrients used by living organisms. The IWI classifies emergent wetlands into two catego- ries: shallow marsh/wet meadow (where standing water or soil saturation is present for brief to moderate periods during the growing season) and deep marsh WETLANDS All Wetlands E3 Bottomland forest Shallow marsh/wet meadow Deep marsh kK} Open water M@ Swamp Q_ Scrub-shrub O Riverine Ei Lacustrine Natural Wetlands 1% 19 N 16% 1 Bottomland forest @ Shallow marsh/wet meadow Deep marsh f— Scrub-shrub WS Open water O Riverine H@ Swamp E Lacustrine Figure 6. Amounts of various types of wetlands as a percentage of all wetlands (top) and of natural wetlands (bottom) for Illinois based on Illinois Wetlands Inventory data, 1980 to 1987. 95 96 WETLANDS Acres [| 0 - 625 (IMM 626 - 1,279 ¥ FRR 1,280 - 2,134 Bae 2,195 - 3,429 HE 3.430 - 10,841 Figure 7. Distribution of forested wetlands by 7.5-minute quadrangle (1980-1987). Source: Suloway et al. 1992. (where standing water is present, or the soil is satu- rated, on a semipermanent to permanent basis during the growing season) (Table 2). Shallow marshes and wet meadows were once common in the state. They are often part of larger wetland complexes, such as the edge of ponds and lakes. The IWI identified 162,913 acres (65,957 ha) (146,873 natural acres; 59,463 ha) of shallow marshes and wet meadow, which represent 81% of emergent wetlands and 13% of all wetland acreage (Table 3). This habitat type has had 44% of its acreage affected by drainage and farming. The largest distribution of this wetland type is in northeastern Illinois, with smaller areas of concentration scattered throughout the state. In the 1980s, 3% of the state’s wetland acreage was deep marsh habitat. There were 38,708 acres (15,671 ha) (25,305 natural acres; 10,245 ha) of this habitat in Illinois (Table 3). The largest concentration of deep marsh occurs in northeastern Illinois, with small areas of concentration at the mouth of the Sangamon River and at Carlyle Lake (Figure 8). Open Water Wetlands. Small and shallow [area < 20 acres (8.1 ha) and depth < 6.6 ft (2 m)] open water (Ml 152 - 375 FR 376 - 779 BH 780 - 1,393 WM 1.394 - 3,951 Sal ( Figure &. Distribution of emergent wetlands by 7.5-minute quadrangle (1980-1987). Source: Suloway et al. 1992. areas are classified as open water wetlands in the IWI. Natural ponds, farm ponds, borrow pits, small reser- voirs, and open water areas that occur within a marsh or swamp are included in this category. Ponds are classified as wetlands because they support typical moist-soil and water-loving plants. In addition, they are often surrounded by marshes or wet forests. Soils may be organic or mineral. Typical plants found in natural ponds include arrowhead, spadderdock (pond lily), and water lily. In the 1980s, open water wetlands accounted for 11% of wetlands, with 143,345 acres (58,034 ha); 89% of this wetland type has been modified or altered by dikes, impoundments, or excavation (Table 3, Figure 6). Three regions have the greatest concentration of open water wetland habitat: the northeast and south- west areas of the state and Fulton County. Scrub-Shrub Wetlands. This type is characterized by woody vegetation less than 20 feet (6 m) tall. Scrub- shrub wetlands can be a successional stage in the transition of an emergent wetland to forest, or it may represent a semi-stable community such as the shrub bogs of northeastern Illinois. About 4% of the state’s wetlands are scrub-shrub. Of the 50,366 acres (20,391 ha) (38,401 natural acres; 15,547 ha) of this habitat, most is found along the Illinois River, northeastern Illinois, or scattered throughout southern Illinois (Table 3). Lacustrine Wetlands Lacustrine wetlands account for 4.4% of the existing wetlands in the state (Figure 6). These wetlands are situated in a topographic depression or are dammed river channels; they are shallow (< 6.6 feet deep), are larger than 20 acres (8.1 ha), and have less than 30% vegetative cover. Permanently flooded natural or artificial lakes and reservoirs are in this group. Lacus- trine wetlands are divided into three types: shallow lake, shore, or emergent wetlands. Most of the lacus- trine wetlands are shallow lake habitat created by dikes, impoundments, or excavation. The 51,868 acres (20,999 ha) (9,354 natural acres; 3,787 ha) of shallow lake habitat is limited to a very small area of the state, mostly along the Illinois River and in northeastern Illinois in Lake and McHenry counties (Table 3). Lake shore wetlands, found along the edges of large rivers and the shores of wave-affected lakes, account for less than 3,000 acres (1,215 ha) (422 natural acres; 171 ha), mainly at Carlyle Lake. Lacustrine wetlands may have a zone of emergent vegetation extending from the shore to a depth of 6.6 foot (2 m). The total area of littoral emergent wetlands in the mid-1980s was 772 acres (313 ha) (531 natural acres; 215 ha) (Table 3). This habitat occurs mostly in the Big Muddy Basin. Riverine Wetlands Riverine wetlands are shallow (< 6.6 feet) waters contained within a channel where water is usually flowing; they are not dominated by vegetation or impounded. Riverine wetlands account for 2.3% of the wetlands in the state and occupy a total area of 29,358 acres (11,886 ha) (19,302 natural acres; 7,815 ha) (Figure 6, Table 3). Shallow water riverine wetlands are concentrated in the Illinois River basin, the west- central portion, and southern quarter of the state. Most of the riverine wetlands are intermittent streams—that is, water flows for only part of the year. Rare Wetland Communities The preceding discussion of types of wetlands was based on the classification system devised for NWI (Cowardin et al. 1979) and subsequently modified for the IWI. The NWI/IWI classification is not designed to separately identify important types of wetlands known as bogs, fens, seeps, springs, and pannes. Because these WETLANDS types are generally unique or rare in Illinois, they were well-documented by the Illinois Natural Areas Inven- tory (INAI). The vegetational communities described in the following section are classified according to the INAI (White 1978), with minor modifications when describing endangered species habitats. Certain wetland community types have never been abundant on a statewide basis, although some may have been locally common in certain regions of Illinois. These rare communities include seeps, pannes, and two peatland types: bogs and fens. These wetlands have been further reduced by land development, and most remnants have become disturbed since early settlement. Relatively undisturbed remnants identified by the INAI are now extraordinarily rare in Illinois; less than 350 acres (142 ha) of each type of rare wetland is considered yo be of high quality (Figure 9). Peatlands. Peatlands are wetlands with organic (rather than mineral) soils developed from partially decom- posed plant material. Organic matter accumulates when plant growth exceeds decomposition. Factors that retard decomposition, such as cold temperature and anaerobic (saturated) conditions, contribute to peat accumulation (Johnson 1985, Crum 1988); thus, peatlands in the Midwest are restricted to the cooler northernmost region extending south to the northern half of Illinois, where most have developed in glacial pothole depressions. Peat in Illinois is derived from three principal sources: sedges, mosses (especially Sphagnum spp.), and limnic origins. The type of peatland is controlled by a complex of climatic, hydrologic, topographic, and geologic factors (Johnson 1985). Two of the three principal types of peatlands occur in Illinois. 1. Minerotrophic peatlands are characterized by a predominantly sedge peat saturated with mineral- rich (alkaline in Illinois), flowing groundwater; this includes all fens in Illinois. 2. Oligotrophic peatlands are characterized by sedge and/or moss peat saturated with ground and rain water, but acidified by a developing Sphagnum mat. These include the level bogs of northeastern Illinois. Some peatlands mostly lacking a Sphag- num mat but not strongly minerotrophic occur in Illinois and can be considered fens (Taft and Solecki 1990), 3. Ombrotrophic peatlands do not occur in Illinois. Ombrotrophic peatlands are rain-fed and receive minerals solely from the atmosphere. These include raised bogs and are the most nutrient poor and most acidic of all peatlands. 97 98 WETLANDS Bog and fen peatland communities have not always been considered distinct, but these wetlands support such unique biota that separate classification for scientific and conservation purposes is desirable. All bogs in Illinois developed from fens in glacial pothole depressions (Sheviak 1974) where hydrological outlets were limited and acids released from certain Sphagnum mosses have affected the local soil and water chemistry (Taft and Solecki 1990). Fens are primarily concentrated in northeastern Illinois (Figure 10), where the calcareous nature of the glacial till often readily mineralizes the groundwater with an alkaline reaction. When groundwater meets a resistent stratum, such as calcareous bedrock in northeastern Illinois, it flows laterally until it issues through the margin of a pothole depression, edge of a moraine, or locally from the sides of river valleys often as diffuse seeps and spring runs (Figure 11). Permanently cold seepage results in cool anaerobic soil conditions, incomplete decomposition, and consequently an accumulation of peat. The precise determination of the total area of original peatland in Illinois is difficult, and distinguishing original bog from fen acreage is not possible. Some estimates can be made from early soil surveys. Accord- ing to Soper and Osbon (1922), several Illinois counties had peat deposits (Figure 12). Although, according to early soil surveys, Lake County supported the most peatland (and muck) in Illinois, the largest single peat deposit was in the former Cattail Slough in Whiteside County, a 1-mile (1.6-km) wide valley 400 Acres Fen Panne Bog Seep Figure 9. Amounts of high-quality rare wetland types in Illinois. extending about 12 miles (19.2 km), with peat mea- sured to a depth of 30 feet (9.7 m) (Soper and Osbon 1922). Peat was being mined in this deposit for fuel long before 1877 (Bent 1877). Early soil surveys included muck soils (organic sediments—plant materials well decomposed and indistinguishable) in their total estimates of peat for each county, probably because muck and peat deposits often occurred within the same wetland complex. This incorporation resulted in an overestimate of peat acreage. Conversely, countless small pothole depres- sions supporting peat occurred throughout the northern third of Illinois and would not have been included in these estimates because individually they were too small; collectively, however, they composed substantial acreage. Furthermore, modern soil surveys are often at least 20 years old and no longer accurately reflect the ws Figure 10. Locations of fens, bogs, seeps, and pannes identified by the Illinois Natural Areas Inventory as significant and relatively undisturbed remnants. Source: White 1978, Illinois Natural Areas Inventory digital database. total area of peatland soils. For this report, the standard measure of the total area of high-quality, relatively undisturbed bogs and fens in the state is based on the INAI (White 1978), and these acreage data are now 15 years old. Despite the difficulty of determining precisely the total area of original peatland in Illinois, the data available, when compared with the results of the INAI, reveal a clear trend suggesting a substantial loss of peatlands (Table 4). Factors leading to the destruction and degradation of peatlands include drainage and subsequent lowering of the water table, cultivation, peat harvesting, grazing by domestic stock, and invasion by exotic species. As a result of oxidation, once a peatland is drained or the hydrology is altered, the peat decomposes, forming muck when wet (Willman and Frye 1970) or humus when drier (Hester and Lamar 1969). For a time, Illinois ranked highly among all states in the amount of peat harvested, second in 1967 and third in 1973 (Samson and Bhagwat 1985). These are surprising statistics considering several other northern states support far greater acreages of peatland. Historically, peat was mined for fuel in Illinois; in more recent years it has been harvested primarily for horticultural use. Six major areas of peat production were located in Illinois during the late 1960s (Figure 12) (Hester and Lamar 1969). Humus was mined from at least one site, and peat and/or humus was mined at two Cook County sites (Willman 1971). Both bogs (Figure 13) and fens support a unique flora adapted to the acidic or alkaline conditions present. Both of these peatland types in Illinois have acted as refugia for plants with current distributions principally Figure 11. Calcareous seepage forming spring run at Bluff City Fen in Cook County. WETLANDS north of Illinois. These northern species became established locally during and following the close of the last (Wisconsinan) glacial episode. Many of these plants are listed as threatened or endangered species in Illinois (Herkert 1991). Fens and bogs each support a total of 34 plant species listed as threatened or endan- gered (Figure 14), more than any other wetland community type in Illinois. For example, within a single wetland complex at Gavin Bog and Prairie Nature Preserve in Lake County, nine threatened and endangered plant species are known to be extant from the bog communities and an additional six threatened and endangered species are present in associated wetland and prairie communities (Table 5). As many as 22 species of threatened and endangered plant species have been reported from Volo Bog (Figure 13) in Lake County (White 1978). However, not all of these species are known to be extant at Volo Bog. In addition to supporting numerous rare species, bog and fen rem- nants in Illinois show considerable floristic variance, with the greatest index of floristic similarity (i.e., how Figure 12. Illinois counties with known peat deposits (shading) and locations of principal peat and humus mining (symbols). Source: Soper and Osbon 1922, Hester and Lamar 1969, and Willman 1971. 99 woe ee WETLANDS, EEE EEE Table 4. Estimates of historical (Soper and Osbon 1922) and contemporary (Soil Conservation Service 1993) acres of peat and muck in Illinois compared with the results of the Illinois Natural Areas Inventory (INAI) (White 1978). County Historical 1993 soil survey INAI Grades peat and muck Muck Peat A and B Boone NA? 35597, 0 0 Cook/DuPage NA 10,341 0 22 DuPage 4,186 a 0 0 Kane 9,299 9,639 0 23 Kankakee 1,747 1,707 0 0 Lake 24,384 L722, 465 286 Lee NA 999 0 (0) Mason NA 1,046 0 0 McHenry NA 20,485 1,760 226 Tazewell 1,344 790 0 0 Whiteside 2,580° 3,455 0 0 Will NA 2,385 0 0 Winnebago 1,427 3557. 0 0 Woodford NA NA 0 5 Statewide 42,387 98,331 2,225 562 * Not available. » See Cook/Dupage © Peat acres only. many species any two sites share) among four Illinois peatlands (two bogs and two fens) and one Indiana bog being 45% (Table 6). These data suggest that any one of the sites is not representative of other sites and that protection of one or two sites is not adequate to preserve the diversity originally established in Illinois peatlands. Pannes. Pannes are interdunal swales restricted to the Lake Michigan lakeshore region where undeveloped portions remain (Figure 10), primarily Illinois Beach State Park and Illinois Dunes North in Lake County. The calcareous nature of the sand, derived from the dolomitic bedrock of the region (Willman 1971), creates an alkaline reaction in the seasonal ponds, and several species are specifically adapted to this habitat. A progression of species can be observed to develop throughout the growing season as the pond level diminishes, exposing pond margins. Several unusual species, including carnivorous bladderworts and species from the Atlantic coast, are found in or are restricted to pannes in Illinois. Seeps. Seeps are wetland communities that are formed where groundwater flows to the surface through porous substrates such as gravel or sand (Ebinger 1978). These communities are similar to springs; the main difference is the manner in which water flows out of the ground. 100 Figure 13. Open water zone of Volo Bog Nature Preserve in Lake County. Volo Bog is the only Illinois bog retaining an open-water zone; all other Iliinois bogs are at a more advanced stage of lakefill. Seep/Spring Fen Bog Swamp Marsh Sedge Meadow Wet Prairie Moist Sand Pond Margin (mud) Panne Open Lake & Pond Flatwoods Floodplain Forest Streamside 0 10 20 30 Number of Species Figure 14. Number of threatened and endangered species found in various types of wetlands in Illinois. In a seep, water generally flows out diffusely, occa- sionally collecting into concentrated spring runs, whereas groundwater in a spring emerges in a concen- trated form, often from a definite opening. The pH of the groundwater that emerges at a seep varies through- out the state, influenced by the type of substrate through which the water flows. The groundwater of most seeps is circumneutral or slightly calcareous (rich in calcium carbonates); some seeps are so calcareous that tufa deposits (precipitates from the highly mineral- ized groundwater) collect where the water emerges. Acid seeps are rare in Illinois. One acid seep occurs in Castle Rock State Park (Ogle County), where the groundwater is mineralized by the St. Peter sandstone. Another is found in the Cretaceous Hills Nature Preserve (Pope County), where groundwater is miner- alized by Cretaceous-aged gravel deposits (White 1978). Seeps are often found in close association with other wetland communities, and boundary distinctions may not be very obvious. Calcareous seeps may be adjacent to some fen communities, and water from some seeps may collect in low areas downslope from the seep and form extensive marshes. In 1978, the Illinois Natural Areas Inventory identified approximately 30 high-quality seeps throughout the state that retained their presettlement condition (Figure 10) (White 1978). The total seep acreage identified by this inventory was 124.2 acres (50.3 ha), with 9.7 acres (3.9 ha) of sand seep communities, 6.0 acres (2.4 ha) of acid seep communities, 14.5 acres (5.9 ha) of calcareous seep communities, and 94.0 acres (38.0 ha) of seep communi- ties with nearly neutral pH conditions. In Illinois, seeps are generally found in stream valleys, along the lower slopes of terraces and ravines. The majority of the inventoried seeps were found in the Fox, Des Plaines, Illinois, and Vermilion river valleys, with scattered locations along the Rock, Kankakee, Kaskaskia, Embarass, Little Wabash, and Big Muddy rivers (Figure 10) (White 1978). In addition to these sites, many smaller or lower quality seeps are found in Illinois. A recent botanical survey along the Middle Fork of the Vermilion River in east-central Illinois identified nine additional seeps (M. Morris, Illinois Natural History Survey, personal communication). In addition to being somewhat mineralized, the ground- water that seeps to the surface is generally cooler than surface water. These characteristics create unique conditions for the development of uncommon plant communities. Often, plants typically known from more northern locations are found within seeps, isolated from their normal ranges. Plants often found in seep communi- ties include marsh marigold, skunk cabbage, grass-of-Parnassus, black ash, willows, jewel weed, joe-pye-weeds, and many sedges and rushes. PRESETTLEMENT WETLANDS Amount An estimate of the quantity and distribution of presettlement wetlands in Illinois was derived from soil survey data. Soils that develop under hydric conditions, regardless of their present use, retain many properties WETLANDS Table 5. Threatened (T) and endangered (E) plants found at Gavin Bog and Prairie Nature Preserve in Lake County (Taft and Solecki 1990). Status in Common name Scientific name Illinois Bearded wheat grass Brownish sedge Awned sedge Three-seeded sedge Leatherleaf Chamaedaphne calyculata White lady’s slipper Cypripedium candidum Small yellow lady’s slipper Cypripedium parviflorum Rusty cotton grass Eriophorum virginicum Tamarack Larix laricina Small sundrops Oenothera perennis Northern gooseberry Ribes hirtellum Agropyron subsecundum Carex brunnescens Carex atherodes Carex trisperma Star-flower Trientalis borealis Highbush blueberry Vaccinium corymbosum Small cranberry Vaccinium oxycoccos SAMMHAmMMTsMM MTA MMMM Marsh speedwell Veronica scutellata Table 6. Sorensen’s similarity indices calculated for four Lake County, Illinois, peatlands (two bogs and two fens) and one Indiana bog (Pinhook) (Taft and Solecki 1990). Marsh communities were included in the comparisons. Numbers represent the percentage of floristic elements in common. Pinhook Wauconda Barrington Volo Gavin 39 39 31 41 Volo 36 45 35 Barrington 32 33 Wauconda 30 diagnostic of wetland soils. Hydric soils have been used as a means to approximate original wetland acreage (Dahl 1990). Hydric soils have been described as being saturated, flooded, or ponded for a sufficient period of time during the growing season to develop anaerobic conditions in the upper part (U.S. Department of Agriculture 1985, Pierce 1989, Wilen 1990). A national list of hydric soils was developed by the National Wetlands Inventory and the Soil Conservation Service (SCS) (U.S. Department of Agriculture 1987). The substrates of deepwater habitats are considered nonsoil because the water is too deep for the growth of emergent vegetation (U.S. Department of Agriculture 1975). Combining soil information with other available data provided a reasonable estimation of the amount and distribution of presettlement wetlands in Illinois. Based on the analyses of soil types, a conservative estimate is that 8,261,600 acres (3,343,424 ha) of wetlands existed in Illinois before settlement by WETLANDS Europeans (Havera 1985); this area represents 23% of the surface area of the state. The estimated amount of wetland soils identifying presettlement wetlands is presented for each county in Figure 15 (see also Appendix 2). This estimated hydric soil acreage is shown as a percentage of wetland soils in each county based on a randomized 2% sampling of Illinois soils (Runge et al. 1969). A more recent soil survey of hydric soil acreage is based on modern soil survey data in the SCS database (J. Doll, Soil Conservation Service, personal communication) (Figure 16; see Appendix 2). Soil mapping, editing, and data preparation are continuing in 24 counties. Thus, the modern soil survey data are not available for the entire state. A preliminary estimate of presettlement wetlands based upon the modern soil survey data in 78 of the 102 Illinois counties is 9,412,659 acres (3,809,251 ha), a value higher than that estimated for the amount of presettlement wetlands in the entire state in the initial determination of hydric acres. Intensive urbanization occurred in Illinois, especially in the metropolitan g Y dae % of County [| 49 HAH 10-19 20-29 BEB 30-39 Riese 40-61 Figure 15. Percentage of each Illinois county before settlement that was wetlands, based upon a 2% soil survey. Sources: Runge 1969, Havera 1985. 102 Chicago area, before modern soil data were amassed. Consequently, estimates of modern hydric soil acreage, or presettlement wetland data, for these areas will be conservative. A recent inventory of wetlands in Illinois (Suloway et al. 1992) revealed that approximately 917,765 acres (371,414 ha) of natural wetlands remained in Illinois (Table 3, Figure 17); only about 6,000 acres (2,429 ha) were high quality and undisturbed (White 1978). Using the modern soil survey incomplete estimate of 9.4 million acres (3.8 million ha) of presettlement wet- lands, Illinois has lost 90.2% of its original wetlands (Figure 18). Many of the original wetlands were lost in the northern two-thirds of the state, particularly east- central Illinois (Figure 19). From presettlement times to the 1980s, natural wetlands in Illinois have declined from at least 23% (and probably more than 26%, using the incomplete modern soil survey) of the state’s surface area to only about 2.6% (Figure 20). Léa] wo “yy % of County [Z) 5-9 FHH 10-19 20-29 BSS 30-39 RE 40+ L__] No data Figure 16. Percentage of each county before settlement that was wetlands, based upon Soil Conservation Service soil surveys currently in progress. Distribution The types and approximate distribution of presettlement wetlands in Illinois are depicted in Figure 21. This estimation of the distribution of presettlement wetlands in Illinois was based predominantly on maps of soil associations. Maps of soil associations were coupled with data on the amount of soil types formed under wetland conditions, maps of organized drainage and levee districts, and historical wetland information to derive an estimate of the approximate distribution of presettlement wetlands in Illinois. The types of presettlement wetlands (i.e., wet prairie, bottomland hardwood, deep marsh, etc.) were determined from historical accounts, maps of forests, and characteristics of soils in the region. The types of presettlement wetlands are generalized designations, which indicate the dominant (but not necessarily the only) wetland type in the area. The distribution of the remaining natural wetlands in Illinois is only a glimmer of the original marshes, shallow lakes, swamps, and wet meadows (Figures 4, 16, 17, 21). % of County lL] 0-1.9 Y4 Uj, EY 23.9 7 4-5.9 Be 6-15 Figure 17. Percentage of each county that was natural wetlands in the 1980s. Source: Suloway et al. 1992. WETLANDS WETLAND PLANTS IN ILLINOIS Plants are important in the determination of wetlands. Unlike wetland hydrology, which may only be visible for part of the year, wetland plants are evident for a much longer time. Water depth is perhaps the most influential physical factor in determining the kinds of plants that occupy a site. Because more plant species are adapted to moist-soil conditions than to open water (strictly aquatic conditions), the shallower the water, the greater the potential diversity of species. Wetlands support a variety of plant life. A total of 108 of the 172 families of vascular plants that occur spontaneously in Illinois contain species that thrive in aquatic or moist-soil habitats. Vascular plants are those with both xylem (supporting and water-conducting tissue) and phloem (food-conducting tissue). Some floating-leaf plants such as water lilies are secondarily vessel-less, indicating a terrestrial origin. Such species are rooted deep below the surface of the water and send up broad, flat leaves that rest on the surface, where photosynthesis occurs. Nutrients move between the leaves and the underwater roots via imperforate tracheids in the plants’ long, slender, flexible stems. Free-floating plants such as duckweeds are not rooted but remain on the surface of the water, usually with their roots dangling. By contrast, emergent plants, Natural wetland acres remaining Presettlement wetland acres destroyed Figure 18. Amount of natural wetlands remaining in the 1980s relative to the amount of presettlement wetlands that have been destroyed. Only about 6,000 acres of high-quality, undisturbed wetlands remain (about 0.05% of the presettlement wetland acreage). 103 WETLANDS V7, | ( ey Y!:. os G % [_] 40-69 FEA 70-79 80-89 BEE 90-99 Figure 19. Percentage of presettlement wetlands lost in each county by the 1980s. including cattails, arrowheads, and bulrushes, are amphibious; that is, they grow with their roots in wet soil for all or part of the year and send up leaves that stand erect above the surface of the water. Submerged plants like pondweeds are also rooted in the soil, but their stems and leaves remain entirely underwater. Other plant types that occupy the drier portions of wetlands include moist-soil plants (sedges), moist-soil shrubs (buttonbush and red osier dogwood), and moist-forest species (tamarack, bald cypress, and silver maple). Some wetlands contain all of these vegetation types, but others have only one or two. Along with water chemistry and hydrology, differences in vegeta- tion help to determine the presence of a wetland and also to distinguish among the various types of wetlands. Groups (Taxonomic and Habit) The species identified in this document as wetland plants are that part of the Illinois vascular flora recognized in the National List of Plant Species that Occur in Wetlands (Reed 1988) and include all species ranked FAC+ and wetter. Botanical nomenclature Natural wetland remaining (2.6%) Wetland destroyed Presettlement nonwetland Figure 20. Percentage of presettlement Illinois that was nonwetland (77%) and wetland (23%) and percentage of the land that remains wetland (2.6%). approximates that of Mohlenbrock (1986). For this report, numerical values used as wetness coefficients have been substituted for the regulatory ranks assigned to each wetland species: —5 = Obligate wetland species (OBL) —4 = Facultative wetland species (FACW+) —3 = Facultative wetland species (FACW) —2 = Facultative wetland species (FACW-) —1 = Facultative species (FAC+) 0 = Facultative species (FAC) 1 = Facultative species (FAC-) 2 = Facultative upland species (FACU+) 3 = Facultative upland species (FACU) 4 = Facultative upland species (FACU-) 5 = Upland species (UPL) These wetland ranks were determined by a nationwide survey of botanists and ecologists and reflect the degree of certainty that a given species will be found in a regulatory wetland. For example, an obligate wetland species (OBL) will be found in a wetland in roughly 99 to 100% of instances. This occurrence diminishes to a mean of 50% for facultative species (FAC). For upland species (UPL), there is a 99 to 100% likelihood that the taxon will be found in an upland habitat (Reed 1988). A qualitative analysis of the Illinois wetland flora revealed several useful perspectives. Most wetland plant species are classified under a broadly defined habit class called forbs (Figure 22). This definition excludes the graminoid monocots such as sedges and grasses but includes most other herbaceous species except vines and ferns. Sedges, species in many wetland community types, rank as the second most important habit group (Figure 22). WETLANDS PRESETTLEMENT WETLANDS [" Northeast glociol lokes Muck ~ "Riverine & upland marshes se Eost-central prairie os Floodplain forest Soythern bottomland forest a *teypress, tupelo) Figure 21. Approximation of the types and distribution of presettlement wetlands in Illinois. This estimate of presettlement wetlands was based principally on maps of soil associations with supportive data from maps of drainage and levee districts, maps of forests, and historical wetland information. Source: Havera 1985. 105 _____. WETLANDS A taxonomic breakdown of the wetland vascular flora indicates that the sedge family (Cyperaceae), with 163 species, is the most species-rich family, followed by the grass family (Poaceae), with 81 species (Figure 23). Other important families include the sunflower (Asteraceae), orchid (Orchidaceae), mint (Lamiaceae), and rose (Rosaceae) families. The most species-rich subfamily rank is the sedge genus Carex, with 90 wetland species. Distribution and Diversity Distribution data for wetland plant species were taken from the Illinois Plant Information Network (ILPIN), a database on the flora of Illinois maintained at the Illinois Natural History Survey (Iverson 1992). An assessment of native wetland vascular plant species known to have occurred in each Illinois county revealed regions of wetland species diversity (Figure 24). Biotic and abiotic elements that contributed to the number of native wetland vascular plants that occurred in each county include county size, diversity of original wetland community types, and, to an extent, intensity of botanical exploration. When all vascular plant species known to occur spontaneously in Illinois, including native and exotic taxa, were considered, the Illinois wetland flora of about 952 species (including varieties) constituted about 32% of the total flora (Figure 25). However, when only species native to Illinois were considered, wetland species identified by the conservative definition used in this report consti- tuted about 42% of the total vascular flora (Figure 26). Abundance The locations of high-quality, relatively undisturbed wetland communities identified during the INAI (White 1978) were concentrated locally along the Fox, Des Plaines, and Kankakee rivers in northeastern Illinois, along the middle Illinois River valley, and in the Gulf Coastal Plain of extreme southern Illinois (Figure 27). The presettlement abundance of natural wetland areas in Illinois (Figure 18) indicates a profound loss of habitat integrity. Of the 9.4 million acres (3.8 million ha) (Appendix 2) (Soil Conservation Service 1993) of wetlands estimated to exist at one time in Illinois, only 6,000 acres (2,429 ha; 0.05% of the original total) persist in an undisturbed condition (White 1978). These undisturbed, high-quality wet- lands are our most reliable qualitative indicator of the original structure and composition of the various wetland communities in Illinois. 106 A total of 1,287 vascular plant species in Illinois are obligate upland species (43%). Obligate wetland species, the next largest single regulatory group, constitute 511 species (17%) (Figure 28). The remain- ing 1,161 taxa (39% of the total flora) have wetness coefficients from —4 to +4 (facultative wetland species [FACW+] to facultative upland species [FACU-}). Most facultative species fall within a range of likeli- hood between 50 and 99% of being found in wetland (wetness coefficients -4 to —1) or upland (wetness coefficients +4 to +1) habitats. The 206 species ranked with the coefficient 0 (facultative species) are esti- mated to have a likelihood between 33 and 50% of being found in a wetland. These taxa were not included in our conservative accounting of the wetland species of Illinois. This accounting indicates that about 54% of the wetland flora in Illinois are almost exclusively found in wetland communities (that is, they have a wetness coefficient of —5). Conversely, about 46% of the wetland species in Illinois (i.e., those with wetness coeffients of -4 to —1) can be found, at least occasion- ally, in upland habitats. Threatened and Endangered Species, Extinc- tions, and Extirpations Twenty-six percent of the 109 federally listed threat- ened and endangered plant species in the United States are wetland-dependent or wetland-related (Feierabend and Zelazny 1987). Approximately 30% of the 2,500 plants in need of federal protection depend upon wetlands (Feierabend and Zelazny 1987). About 17% Vines Ferns Trees Shrubs Sedges Grasses Forbs 100 200 300 400 500 600 Number of Species Figure 22. Number of wetland plant species per growth habit group in Illinois. of the native vascular flora (wetland and upland) in Illinois (Figure 29) and 18.6% of the native wetland flora (Figure 30) are listed as threatened or endangered (Bowles et al. 1991). Illustrating the number of threatened and endangered wetland plant species for each county revealed a primary concentration of rare wetland species in northeastern Illinois and secondary concentration in far southern Illinois (Figure 31). Depicting the number of threatened and endangered wetland species extirpated in each county also revealed a concentration in the heavily developed northeastern counties (Herkert 1991) (Figure 32). (Extirpated means a species was formerly found in a given region but is no longer believed to occur there; extinct means a species no longer exists anywhere.) High rates of extirpations of threatened and endangered wetland species were also present in the Illinois River counties of Peoria, Tazewell, Cass, and adjacent Menard and in the southwestern Illinois counties of St. Clair, Alexander, Jackson, Union, and Pulaski (Figure 32). The northeastern counties of Lake, Cook, and McHenry supported the greatest number of rare wetland plant species in Illinois (Figures 31, 32). Lake County historically hosted the greatest number of wetland plant species that are listed as threatened and endangered, with a total of 80; currently, Lake County, with 66 threatened and endangered wetland species, still ranks highest of all Illinois counties. Cook County formerly ranked second among Illinois counties, with a total of 74 wetland plant species that are listed as Apiaceae Polygonaceae Potamogetonaceae Salicaceae Ranunculaceae Scrophulariaceae Rosaceae Lamiaceae Orchidaceae Asteraceae Poaceae Cyperaceae 0 20 40 60 80 100 120 140 160 180 200 Number of Species Figure 23. A ranking of the vascular plant families with the most wetland species in Illinois. WETLANDS threatened and endangered today. However, the extirpation of 36 of these species placed Cook behind McHenry County, which still supported 41 threatened and endangered wetland species though it lost 16. Some counties, such as Peoria, Tazewell, Kankakee, St. Clair, Menard, Hancock, Alexander, Winnebago, and Ogle, have had exceptionally high rates of extirpa- tions of threatened and endangered wetland plant species. Comparing the number of county occurrences of threatened and endangered wetland plant species with the number of county extirpations from 1981 (Sheviak 1981) and 1991 (Herkert 1991) appears to indicate a measure of recovery (Figure 33). However, the total number actually demonstrates increased knowledge of the distribution of rare wetland plants throughout Illinois as a result of additional field work (Bowles et al. 1991). Although we may never have a complete record of the distribution and frequency patterns of all rare wetland species, some of which are cryptic and may not be present during every growing season, & Bee atte ti 300-399 SS . 400-499 ALAS GT 500 iS Figure 24. Number of native wetland plant species recorded from each Illinois county. Not all of these species can Still be found in each county. 107 WETLANDS Wetland species Upland species Figure 25. Percentage of wetland species in the Illinois vascular flora (native and non-native species). existing knowledge identifies the regions that support the greatest diversity of rare (Figure 31) as well as more common species (Figure 24). An analysis of threatened and endangered wetland species by habitat type indicates, as previously men- tioned, that the peatland bog and fen communities, each with 34, support the greatest number of threatened and endangered plant species (Figure 14). Another habitat that contains numerous rare wetland species, moist sand, is an amalgamation of several habitat types unified artificially by the similar characteristic of moist sand. These include portions of the Chicago lakeplain, margins of sand ponds, and moist sand prairie. Swamps (principally in southern Illinois), floodplain forests (also mostly those in southern Illinois), seeps and springs, pannes, and marshes also support more than 10 threatened and endangered wetland plant species each (Figure 14). Species extirpated from Illinois were not included in this analysis. Approximately 34 wetland plant species appear to have become extirpated from the state, and these have been removed from the list of endangered species in Illinois (Bowles et al. 1991, Post 1991, Sheviak 1974, Taft 1993) (Table 7). Several additional wetland species still listed as endangered (Herkert 1991) are not presently known from extant Illinois populations, and at least one, the Illinois endemic thismia, may actually be extinct. Most, but not all, of these extirpated species were confined to wetlands in the north, specifically, the heavily urbanized northeastern counties. 108 Upland species Wetland species Figure 26. Percentage of wetland species in the native Illinois flora. Non-native Species Distinguishing plant species that are native to Illinois from those that are non-native is important in understand- ing the value of high-quality wetlands. Non-native species, otherwise known as exotic, alien, or introduced species, are those that were not present in Illinois before European settlement of North America. Some non-native species have been introduced for landscaping or agricul- tural use, whereas others arrived as accidental hitchhikers from other regions. The percentage of non-native plant species in the overall flora of Illinois has risen from an estimated 10.2% in 1846 to 30.1% in 1988 (Figure 34) (Henry and Scott 1980, Reed 1988). By contrast, only 90 (9.4%) of the 952 wetland flora species are non-native, reflecting the greater association of non-native species with drier, more frequently disturbed habitats, such as agricultural fields and urban areas (Figure 35). This uneven distribution of non-native species over the wetness gradient can be further illustrated by ranking all plant species by wetness ranks (see previous section on wetland plant groups for explanation). The percentage of non-native species at each rank ranges from approxi- mately 7.0% for those plants ranked —S (OBL) to 48.0% for those species ranked 5 (UPL) (Figure 36) (Reed 1988). The percentage of wetland plants in Illinois that are non-native is unevenly distributed among the various habit groups (vines, ferns, trees, shrubs, sedges, grasses, and forbs). These values range from 4.8% of the shrub flora to 17.4% of the grasses. No non-native woody vines or ferns are found in the wetlands of Illinois (Figure 37) (Reed 1988). Although the percentage of non-native species within the total wetland flora is low (9.4%), a few non-native plant species can have devastating effects in natural wetland habitats. Non-native species, once freed of the natural controls in their countries of origin, often spread rapidly and relatively unimpeded in their new habitats. The most deleterious effect of the invasion and establishment of non-native species in native plant and animal communities is a change in the plant community structure. An associated decrease in the plant and animal diversity of an area usually occurs, resulting in an overall loss in our natural heritage (Bratton 1982, Harty 1986). Other undesirable effects from non-native species can include changes in the nutrient balance in the soil, a lowering of the water table, and modifications to the disturbance regime (Bratton 1982). All Illinois counties have felt the deleterious impact of non-native species; however, nowhere in the state is the impact more important than in the counties of the greater Chicago area (Figure 38) Figure 27. Locations of high-quality wetland communi- ties identified by the Illinois Natural Areas Inventory. These are sites recognized as relatively undisturbed significant features (grades A and B). WETLANDS (Reed 1988, Iverson 1992). In Illinois, over a four-year period (1989 through 1992) the Division of Natural Heritage in the Illinois Department of Conservation spent an average of 233 man-days/year (approximately $35,000/year in labor costs) on the control of non-native species in high-quality natural areas. 1000 750 500 Number of Species 250 Sree sea — a Qe as Wetness rank Figure 28. Number of Illinois plant species, including native and non-native species, occurring at each wetness rank. A rank of -5 indicates an obligate wetland species and a rank of 5 denotes an upland species. See text for additional information. 9.47% (0 Upland Species - Unlisted [] T & E Upland Species HI Wetland Species - Unlisted EH 1 & E Wetland Species Figure 29. Number and percentage of species in the upland and wetland native Illinois flora listed as threatened and endangered. 109 _______ WETLANDS T & E wetland species Native wetland species that are not listed Figure 30. Number and percentage of native Illinois wetland flora listed as threatened and endangered species. Ree ‘X oe | | SE Figure 31. Number of threatened and endangered wetland plant species known from extant poulations in each Illinois county. 110 Despite a steady increase in the amount of time and money spent on control, the spread of these non-natives has continued (Francis M. Harty, Illinois Department of Conservation, personal communication). The two most important non-native speciesthat seriously affect wetland habitats are purple loosestrife and glossy buckthorn. Purple loosestrife is a wetland plant from northern Europe, where it occurs in scat- tered locations in marshes and sea shores. Seeds of purple loosestrife probably arrived in North America in the early 1800s in ship ballast (Thompson et al. 1987). In the absence of natural predators and competitors in the New World, the plant spread rapidly in the north- eastern United States during the 19th century, mainly along commercial shipping routes. By 1980, purple loosestrife had become firmly established in wetlands in the eastern United States and had spread to the West Coast (Schwegman 1985, Thompson et al. 1987). Once established in wetland habitats such as bogs, marshes, fens, and sedge meadows, and along reservoirs and ditches, the plants spread rapidly and displaced native Figure 32. Number of extirpations of threatened and endangered wetland plant species in each Illinois county. plants, thereby decreasing native plant diversity and habitat quality for wildlife (Heidorn and Anderson 1991). Purple loosestrife reached Illinois sometime before 1940 (Thompson et al. 1987). In 1955, purple loos- estrife was known from five counties (Jones and Fuller 1955); by 1985, it had spread to at least 25 counties (Figure 39) (Jones and Fuller 1955, Winterringer and Evers 1960, Mohlenbrock and Ladd 1978, Ladd and Mohlenbrock 1983, Mohlenbrock 1985). The most serious infestations are localized in the northeastern part of the state, an area with both high-quality wetlands and strong pressures from urban develop- ment. Purple loosestrife is now found in nearly all significant wetlands in the region, including those with high natural quality (Randy Heidorn, Illinois Depart- ment of Conservation, personal communication). Other parts of Illinois in which loosestrife has spread rapidly include wetlands along the Mississippi, Kankakee, Illinois, and Rock rivers (Schwegman 1985). Nation- wide, the annual cost of the infestation for wildlife and agriculture is about $45 million (Thompson 1991). Purple loosestrife is designated as an exotic species by the Illinois Exotic Weed Act of 1988, which forbids its sale in Illinois (Gould and Gould 1991). Control of this pernicious non-native weed is difficult because of its ability to produce copious amounts of seed and to reproduce vegetatively by stem and root fragments. One solution for limiting the abundance of purple 2 goose Ss S i 300 5 ” o 2 200 gE = 8 ° > 100 ° ra) a) 0. iy 1981 1991 O extant @ extirpated Figure 33. Number of county occurrences and county extirpations of threatened and endangered wetland species in Illinois, 1981 and 1991. WETLANDS loosestrife may be the successful discovery and introduction of a biological control agent (Thompson et al. 1987). Glossy buckthorn, a European shrub, was brought to the United States for use as an ornamental plant and has now become established throughout the eastern states (Howell and Blackwell 1977). Glossy buckthorn was first documented in Illinois in 1912 at Skokie Marsh in northern Cook County (Sherff 1912). By 1978, the species had spread to 18 counties, mostly in northeastern Illinois (Figure 40) (Sherff 1912, Jones and Fuller 1955, Winterringer and Evers 1960, Mohlenbrock and Ladd 1978). Glossy buckthorn Table 7. Wetland plant species thought to be extir- pated from Illinois. This list does not include species still listed as endangered with no known extant populations in Illinois. Common name Bog rosemary Dragon’s mouth orchid Drooping wood reed Bluebead Early coral root Waterwort Spike rush Horsetail spike rush Marsh horsetail Brown plume grass Umbrella grass Purple avens Rattlesnake manna grass Goldenpert Mare’s tail Engelmann’s quillwort St. John’s wort Twinflower Water hyssop Mountain holly Phlox White-fringed orchid Tall white orchid Hooker’s orchid Marsh bluegrass Pondweed Pondweed Spearwort Small yellow crowfoot Bulrush Bulrush Bulrush Least burreed Virginia chain fern Scientific name Andromeda polifolia var. glaucophylla Arethusa bulbosa Cinna latifolia Clintonia borealis Corallorhiza trifida Elatine brachysperma Eleocharis caribaea Eleocharis equisetoides Equisetum palustre Erianthus brevibarbis Fuirena scirpoidea Geum rivale Glyceria canadensis Gratiola aurea Hippuris vulgaris Isoetes engelmannii Hypericum ellipticum Linnaea borealis Mecardonia acuminata Nemopanthus mucronatus Phlox carolina var. angusta Platanthera blephariglottis Platanthera dilatata Platanthera hookeri Poa paludigena Potamogeton epihydrus Potamogeton vaseyi Ranunculus ambigens Ranunculus gmelinii Scirpus microcarpus Scirpus pedicellatus Scirpus subterminalis Sparganium minimum Woodwardia virginica 111 WETLANDS % Non-native Species (Ol IS, 0 00; IDO iF a0 i 0): Go. p> ae PP te Ml oss A To ee) ait o TR To HR el inne) OOP G0) 00) 00s O01 10) (One OO) OG), 10) 16) le 0 SS eee ie ee ford ose) a is ger. oe Year Figure 34. Percentage of non-native plant species in the Illinois flora, 1846 to 1988. commonly invades bogs, fens, and sedge meadows (Heidorn 1991). The starling, a species of bird intro- duced from Europe and now a pest in North America, is the primary dispersal agent of glossy buckthorn fruits (Howell and Blackwell 1977). Once glossy buckthorn invades a natural wetland, it forms dense shrub thickets that overtop native shrubs and herbs, thereby decreasing the native biological diversity of the wetland (Taft and Solecki 1990, Heidorn 1991). Control methods for glossy buckthorn are labor intensive (Heidorn 1991), and the total infested acreage that can be treated using these methods is limited. WETLAND ANIMALS IN ILLINOIS Distribution, Diversity, and Abundance The plant and animal communities found in wetlands are extremely complex and are intertwined through food webs and nutrient cycles. Wetlands abound with animal life. High proportions of bird, mammal, amphibian, and reptile species depend upon or utilize wetland habitats in Illinois (Figure 41). There is some degree of subjectivity in identifying animals as wetland species. Some wetland animal species are exclusively limited to wetlands, others may occur in upland or wetland habitats, and some may predominantly inhabit uplands. Birds. Birds are unique among wetland inhabitants because many are migratory and rely on widely 112 Native upland species Native wetland species Non-native wetland species (3%) Non-native upland species Figure 35. Number and percentage of native and non- native wetland and upland plant species in the Illinois flora. 1500 1250 Non-native species » 1000 Native species 2 ° 3 750 a) i“ 8 500 E EI za 250 Wetness rank Figure 36. Abundance of non-native and native Illinois plant species at each wetness rank. (Values at top of bars represent the percentage of non-native species at each wetness rank. A wetness rank of —5 indicates an obligate wetland species; a rank of 5 indicates an upland species. dispersed wetlands on a seasonal basis. Wetland plants provide cover, nest sites, and food for birds, and they provide habitat for other animals, such as insects, that are used for food (Benyus 1989). Many migrant species use wetlands for foraging and resting during migration (Figure 42), and some migrants may return each year to the same wetlands to feed and raise their young. Waterfowl, wading birds, shorebirds, and numerous songbirds depend upon wetlands. Some birds have highly specific habitat requirements, and others have more general habitat needs; therefore, the availability of a diversity of wetland habitats and wetland com- plexes is essential to support their populations. Vines HB Non-native species Native species Ferns Trees Shrubs Sedges Grasses Forbs 200 300 400 600 700 Number of Species Figure 37. Number and percentage of non-native and native wetland plant species per growth habit group. (Values at end of bars represent the percentage of non- native species in each habit group.) More than 439 bird species have been documented in Illinois. This discussion will address only the 274 more commonly observed species, including endangered or threatened species (Bohlen 1989) (see Appendix 3). The number of bird species using wetlands may be greater today than in presettlement times. As the land was cultivated and urbanized, those wetlands that were too wet or costly to develop remained as refugia in a disturbed environment. The mobility of birds allows them to exploit many types of habitat to fulfill their physiological requirements. Therefore, any of the 274 bird species listed in Appendix 3 can use wetlands for nesting, foraging, or resting during breeding, migra- tion, or wintering seasons (Figure 41). Of these 274 species, 24 typically depend on wetland habitats for nesting or foraging sites, 81 are strongly associated with wetland habitats during their life cycles, and the remaining 169 use wetlands opportunistically at some time during the year. Other than a study in northeastern Illinois by the Illinois Department of Conservation and aerial invento- ries by the Illinois Natural History Survey, no long-term studies of avian use of wetland habitats have been conducted in Illinois. Studies of this type are difficult because of the dynamic nature of wetland habitats. Wetland characteristics, such as water level and amount of vegetation cover, can change dramati- Figure 38. Number of non-native wetland plant species found in each Illinois county. cally due to climatic effects or physical disturbance. Depending on the age of a wetland, water depth, annual temperature, and amount of precipitation, wetlands can vary from saturated to dry, or from open water to choked with vegetation, both seasonally and annually. Therefore, many wetland bird species are not guaran- teed a predictable or favorable environment each year and must search out new and suitable wetlands in which to build their nests, or develop strategies to cope with these changing conditions. For example, one strategy, which allows birds that require standing water to nest in small, seasonal wetlands, is to breed rela- tively early in the season when standing water from winter thaw and spring rains is present. As these wetlands dry out, birds may move to more suitable habitats to raise their young (perhaps larger wetlands or lakes with more stable water levels). The numbers and distributions of many species of wetland-dependent birds have decreased in response to the destruction and degradation of wetlands throughout the state (Bohlen 1989, Herkert 1992). Many of the wetland-dependent bird species are now listed as WETLANDS ____ 113 —______. WETLANDS EES aaa rep Se (ae Rae pSesee] eee oo Figure 39. Spread of the non-native species purple loosestrife in Illinois counties by year first observed. state-endangered or -threatened. The king rail is an example of a wetland-dependent species whose numbers have decreased because of wetland destruc- tion. Ridgway (1895) noted that the king rail was a common summer resident in suitable habitat through- out the state. Today, the king rail is an occasional migrant and summer resident in Illinois. Bohlen (1989) noted that in view of its rarity today, the many histori- cal nest records for the king rail in Illinois testify to its definite population decline. Demographic data are scarce for many bird species that use wetlands as opportunists. It may be impossible to correlate population fluctuations or changes in occur- rence for these species to changes in wetland habitats because these birds do not exclusively depend on wetlands and can shift their use among other habitats to fulfill their nesting, foraging, and resting needs. Also, true population trends of Illinois’ bird species may be confounded by the increase in bird-watchers beginning in the 1970s. This increase in effort produced a greater number of observations at more locations for many bird species, but these data do not confirm an increase 114 Rend 1912 RES 1955 [28] 1960 1978 Figure 40. Spread of the non-native species glossy buckthorn in Illinois counties by year first observed in population numbers or distribution. More research is needed to document bird species that opportunistically use wetland habitats in Illinois. Colonial nesting bird species. Colonial bird species are those that nest in groups (Figure 43). Colonies can be composed of one species or several different species of birds. Colonial birds include the great blue heron, great egret, snowy egret, little blue heron, cattle egret, black-crowned night-heron, and the double-crested cormorant. Descriptions of heron colonies in Illinois date to 1888 (Barnes 1909), but many of the early published records are vague or incomplete, and the number of colonies and individuals can not be deter- mined with any certainty (Graber et al. 1978). Heron colonies are dynamic. Fluctuations in species composition and in the number of individuals are common. Lack of information on individual move- ments, annual variation, and problems with censusing heron colonies makes the evaluation of long-term population trends for these species difficult (Graber et al. 1978). ee ee ee. ee 300 O Don't use 200 wetlands — Use wetlands 100 Number of Species Amphibians Reptiles Birds Mammals Figure 41. The proportion of amphibians, reptiles, birds, and mammals in Illinois that use wetlands. Graber et al. (1978) investigated historical information and conducted censuses of colonies from 1973 to 1977. Broad-scale estimates of colony numbers from before 1900 through 1977 are available (Figure 44). The Illinois Department of Conservation began intensive heron colony surveys (both aerial and ground) in 1983. Most of the Department’s censuses were aerial esti- mates (less accurate than ground counts), and all colonies were not censused in each year; however, the aerial censuses illustrate general overall trends in numbers of colonies, species, and individuals for colonial nesting birds in the state. Data suggest that larger, long-lived colonies, most of which contain more than one species, typically occur in floodplain forests along major rivers and reservoirs. Smaller colonies, typically composed of only great blue herons, occur in floodplain forests and smaller woodlots that are either near or away from water. Herons and egrets also nest in scrub-shrub and emer- gent wetlands. Herons, egrets, and double-crested cormorants depend on shallow-water and deep-water wetlands as foraging habitat; the more terrestrial cattle egret is an exception. Total numbers of great blue herons, great egrets, and double-crested cormorants have increased since 1983, but black-crowned night-herons have decreased in number (Figure 45). Insufficient data are available to document population trends for snowy egrets and little blue herons, which were never very common in the State, or cattle egrets, a self-introduced exotic (Graber et al. 1978). There were approximately 30 known Figure 42. Yellow-headed blackbird, one of many migrant bird species for which wetlands are important foraging and resting sites. (Photo taken at McKee Marsh, Dupage County, Illinois, by Joe Milosevich). heron nesting colonies in Illinois in 1983, and the number increased to 38 in 1991 (Figure 46). Both great blue herons and great egrets have increased their numbers of breeding colonies in the state, but the black-crowned night-heron has decreased its number of nesting locations (Figure 47). An increase in observers in recent years has added to the number of heron colony locations and nests counted; however, these increases are not confirmation of true population increases. Special attention must be given to those species that, in spite of increased census efforts, appear to be decreasing in distribution or population numbers (e.g., the black-crowned night-heron) (Figure 48). Since the turn of the century, herons and egrets have suffered population declines because of plume hunters, hydrocarbon pollution, vandalism, human encroach- ment, and habitat destruction (Graber et al. 1978). Protective legislation prohibits the persecution of these species, but habitat manipulation and destruction continues to be a major threat. Waterfowl. Dabbling ducks. In Illinois, the mallard is the most abundant species of duck (Figure 49). The Illinois River valley historically has been one of the most important migration areas for mallards in the United States. Frederick Lincoln, the first person to 115 WETLANDS band ducks in the United States, placed bands on mallards in 1922 in the Illinois River valley. Lincoln noted that “when all the other ducks are gone, there will still be mallards on the Illinois” (Heilner 1943:88). Peak population numbers are an excellent indicator of the changes in the numbers of various species of waterfowl occurring in an area from year to year. The peak population number is the highest number of individuals of a species that was inventoried in a region on any one of the several aerial censuses conducted by the Illinois Natural History Survey during each fall. Inventory data for peak numbers of waterfowl are presented in Figures 50-52 as a three-year moving average, with the data plotted on the third year, to minimize annual fluctuations and emphasize long-term trends. Plotting the peak counts of mallards during fall in the Illinois River and the central Mississippi River regions from 1948 to 1991 (Figure 50) indicated that the Illinois River region from Henry to Grafton has generally accommodated higher numbers of mallards than the central Mississippi River region from Grafton to Rock Island. For example, a peak number of 1,617,575 mallards was recorded for the Illinois River region as compared with 181,405 in the central Mississippi River region in 1948. In recent years, however, the difference in the peak numbers of mallards in these two regions has become smaller. A significant (P < 0.005) downward trend in mallard numbers was documented in the Illinois River and central Mississippi River regions separately and also combined during 1948-1991 (Havera 1992). The Figure 43. Colonial bird species (great blue heron, great egret, double-crested cormorant are pictured) nesting at the Lake Renwick Heron Colony in Will County. (Photo taken by Joe Milosevich.) 116 number of mallards in North America has been declining in recent decades, and the downward trend in the numbers of mallards observed in the Illinois and central Mississippi River regions is influenced by the overall number of mallards in North America. How- ever, wetlands in the Illinois River valley have been degraded by sedimentation, which has greatly reduced the variety and abundance of aquatic plants and other natural foods available to mallards. Thus far, the aquatic plant life of the Mississippi River has been less affected by sedimentation, but detrimental effects are becoming apparent. In addition, increased tillage of harvested corn fields in central Illinois during fall sharply decreased the waste grain resource for mallards and other field-feeding species (Warner et al. 1985). The Illinois River and central Mississippi River regions are extremely important to mallards. From 1953 to 1991, an average of 22.7% of all the mallards wintering in the Mississippi Flyway were in the Illinois River region during one day of the fall migration. Similarly, an average of 14.7% of all the mallards wintering in the Mississippi Flyway were in the central Mississippi River region during one day of the fall migration. For both regions, an average of 35.4% of all the mallards wintering in the Mississippi Flyway passed through the Illinois and central Mississippi River regions (Havera 1992). Diving ducks. The drastic decline of the lesser scaups and canvasbacks in the Illinois River region and the Number of colonies <1900 1900-1949 >1950 1977 Years Figure 44, Estimated number of heron colonies in Illinois, before 1900 to 1977 (GBH = great blue heron, GE = great egret, LBH = little blue heron, BCNH = black crowned night-heron, SE = snowy egret). 4000 Number of Individuals Year Figure 45. Number of individuals of five colonial bird species that use Illinois wetlands, 1983 to 1991 (GBH = great blue heron, GE = great egret, LBH = little blue heron, BCNH = black crowned night-heron, DCC = double-crested cormorant). subsequent increase in numbers of these species in the central Mississippi River region are particularly notewor- thy. The plant and animal food resources utilized by lesser scaups, canvasbacks, and other species of diving ducks began disappearing from the upper Illinois River valley in the mid-1950s and have not recovered. The aquatic plants in the Illinois Valley were affected by sedimentation (Bellrose et al. 1979, Havera and Bellrose 1985), and the benthic macroinvertebrate community was likely affected by toxins, possibly high concentra- tions of ammonia (R.E. Sparks, Illinois Natural History Survey, personal communication). Pool 19 (Keokuk Pool) of the Mississippi River is the most important migration area for diving ducks in the Midwest. Pool 19 has hosted large and varying numbers of lesser scaups and canvasbacks and reason- able numbers of other species. Because of recent dramatic fluctuations in the aquatic plant and animal populations, the outlook for the food base of diving ducks in Pool 19 and elsewhere in the upper Missis- sippi River is dubious. Additionally, human distur- bance has been documented to affect adversely the numbers of diving ducks on Pool 7 and Pool 19 (Korschgen et al. 1985, Havera et al. 1992). Lesser scaups were abundant in the Illinois Valley before the mid-1950s. The decline in the numbers of lesser scaups utilizing the Illinois River region and the WETLANDS Number of Colonies 1983 1985 1987 1989 1991 Year Figure 46. Number of colonies of five heron species in Illinois, 1983 to 1991 (GBH = great blue heron, GE = great egret, LBH = little blue heron, CE = cattle egret, BCNH = black crowned night-heron). Figure 47. Counties in which nesting black-crowned night herons were found before and after 1980. 117 WETLANDS increase in the numbers stopping on Pool 19 in the central Mississippi River region since 1948 are apparent (Figure 51) (Havera 1992). The crash in the peak numbers of lesser scaups, primarily on renowned Upper Peoria Lake, occurred in the 1950s. The peak numbers of lesser scaups recorded in the Illinois River region from Peoria northward were 585,100 in 1954, 73,650 in 1955, 34,250 in 1956, and 10,075 in 1957. Subsequently, the numbers of lesser scaups stopping in this stretch of the Illinois River have never recovered. On Pool 19 in the central Mississippi River region, however, numbers of lesser scaups began to increase steadily after 1950 and reached a zenith of 686,500 in 1969. Unfortunately, the trend in lesser scaup numbers has been downward since then. In 1991, only 19,050 lesser scaups were observed on the Mississippi River from Keokuk, Iowa, to Rock Island, Illinois—the lowest number since the aerial inventories were begun in 1948 (Havera 1992). The highest number of canvasbacks inventoried in the Illinois River region occurred on the beds of aquatic vegetation on Upper Peoria Lake, where 95,000 were present in November 1953 and 85,000 were recorded in October 1952 (Havera 1992). The peak number of canvasbacks recorded in the Illinois River region north of Peoria was 105,160 in 1952 and 103,500 in 1953; in 1971, a maximum of 120 were observed there (Figure 52). Similar to the numbers of lesser scaups, the numbers of canvasbacks crashed in the Illinois River region in the mid-1950s. The numbers of canvasbacks had not recovered to any reasonable levels by 1991. In the central Mississippi River region, the numbers of canvasbacks began to increase in 1963, mainly on Pool 19, and, after a downturn in the mid-1970s, reached Figure 48. The black-crowned night heron, whose numbers have been declining in Illinois. (Photo taken at Channahon, Will County, by Joe Milosevich.) 118 their maximum number of 188,150 in 1978. Since 1978, the number of canvasbacks has been sliding downward in this stretch of the Mississippi River; only a maximum of 22,765 were observed there in 1989 (Havera 1992). Mammals. Of the 59 species of mammals in Illinois, at least 46 use wetland habitats (Hoffmeister 1989,Hofmann 1991) (Figure 41, Appendix 4). Rela- tively few mammal species are specifically adapted for living in wetlands (Fritzell 1988), but wetlands provide abundant food (e.g., invertebrates, amphibians, waterfowl eggs and nestlings) and cover for a variety of mammals. Larger mammals, such as the bobcat and white-tailed deer, have home ranges that can encompass a mosaic of = eS hee Se ree — - Sa if OR .- ae ~~ _ Figure 49. The mallard, the most abundant duck in Illinois during fall migration. —+— Illinois River ——@— Mississippi River Fall Peak Numbers (Thousands) 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 Year Figure 50. Peak numbers (3-year moving average) of mallards aerially inventoried during fall in the Illinois and central Mississippi River regions, 1948 to 1991]. forested and open habitats, including wetlands. Some species of small mammals (insectivores and rodents) have broad environmental tolerances, and individuals can be found in a range of habitats from wetlands to uplands. The Virginia opossum occupies a variety of habitats but is often found near water. Most shrews require moist microclimatic conditions; four Illinois species are known to occur in wetlands but are not restricted to them (Hoffmeister 1989, Mumford and Whitaker 1982). The eastern mole occurs in both forests and open habitats, including areas that are periodically inundated (Mumford and Whitaker 1982). Bats are not typically considered wetland animals, but all 12 species that occur in Illinois are listed in Appendix 4 as mammals that use wetlands. Bats forage in and above floodplain forests and above ponds, marshes, and bogs as well as in and above upland forests, above streams and fields, and near buildings (Barbour and Davis 1969, Hoffmeister 1989). In addition, most bat species in Illinois roost in trees, at least occasionally, during the summer and could use floodplain forests for that purpose. The importance of floodplain forests as bat habitat is indicated by recent captures of all species that occur in Illinois along the Cache River (Illinois Natural History Survey and Illinois Department of Conserva- tion, unpublished data). The swamp rabbit inhabits only bottomland forest and swamps in southern Illinois (Hoffmeister 1989, Kjolhaug et al. 1987). Sixteen species of rodents can be found in wetlands, although few are limited to such habitats (Hoffmeister 1989, Mumford and Whitaker 1982). The rodents most closely associated with wetlands are the beaver, muskrat, and marsh rice rat. Ten of Illinois’ carnivore species use wetland habitats; ponds and emergent wetlands, for example, are good hunting areas for predators. The carnivores most strongly associated with wetlands are the raccoon, mink, and river otter. The white-tailed deer (the largest mammal still present in Illinois) uses wetlands, especially forested wetlands, for foraging and cover. Several of the mammal species that utilize wetlands are of economic importance as furbearers or game animals. Continued losses of wetlands to agriculture and urbanization would decrease the amount of suitable habitat available to the majority of mammal species in Illinois. This loss would have the greatest impact on the species that are limited to or primarily found in wetland habitats. Two such wetland species are the marsh rice rat and swamp rabbit, which both have limited ranges in the state and occur in scattered populations that are vulnerable to local extirpation (Hofmann et al. 1990, Kjolhaug et al. 1987). Destruc- WETLANDS tion and fragmentation of bottomland forest has already had an adverse impact on the swamp rabbit (Kjolhaug et al. 1987). In Illinois, historical records suggest that this species was once widely distributed in the Missis- sippi, Big Muddy, Kaskaskia, Ohio, Cache, Wabash, Little Wabash, and Saline river drainages, occurring as far north as Calhoun, Bond, and Lawrence counties (Kjolhaug et al. 1987) (Figure 53). During extensive searches in 1984 and 1985, swamp rabbits were found at 22 locations in only eight counties (Kjolhaug et al. 1987) (Figure 53). Similar declines in swamp rabbit numbers as a result of habitat loss have been noted in —+}— Illinois River ——*®— Mississippi River Fall Peak Number (Thousands) 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 Year Figure 51. Peak numbers (3-year moving average) of lesser scaups aerially inventoried during fall in the Illinois and central Mississippi River regions, 1948 to 1991, —+t— Illinois River ~—®— Mississippi River (Thousands) Fall Peak Numbers 22 050 08 828, 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 Year Figure 52. Peak numbers (3-year moving average) of canvasbacks aerially inventoried during fall in the Illinois and central Mississippi River regions, 1948 to 199]. 119 Missouri and Indiana (Korte and Fredrickson 1977, Whitaker and Arbell 1986). Amphibians. Amphibians are an important component of many ecosystems. They can constitute a large proportion of the total vertebrate biomass of an ecologi- cal community (Burton and Likens 1975). They also are a vital link in food webs. Amphibians are major consum- ers of arthropods, mollusks, and annelids, and they can have a significant role in insect control. Amphibians, in turn, are an important source of food for many predatory fish, reptiles, birds, and mammals. Because the life history of most amphibians includes both aquatic and terrestrial stages, 37 of the 41 amphibian species that occur in Illinois use wetland habitats at least part of the time (Smith 1961; Conant and Collins 1991; R.A. Brandon, Southern Illinois University, personal communication; C.A. Phillips, Washington University, personal communication) (Figure 41, Appendix 5). Most salamanders are aquatic as larvae and terrestrial as adults, although adults require moist microclimatic conditions because of their susceptibility to desiccation. Twenty species of salamanders occur in Illinois (Morris et al. 1983, Phillips 1991), and most of these (16) use wetland habitats at least for breeding and larval develop- ment. The ambystomatid salamanders (eight species) are terrestrial or fossorial as adults; most of these species inhabit swamps or floodplain forest, although some may also occur in moist, wooded upland areas (Smith 1961). All use permanent ponds or vernal pools for breeding. The adult eastern newt has both terrestrial and aquatic stages, with the aquatic form occurring in ponds and marshes (Smith 1961). Three Illinois plethodontids are completely terrestrial (no aquatic larval stage) and typically are found on wooded hillsides, but five other plethodontids in the state occur in springs, seeps, bogs, and swamps (Smith 1961; C.A. Phillips, Washington University, personal communication; R.A. Brandon, Southern Illinois University, personal communication). The mudpuppy, primarily an inhabitant of lakes, rivers, and large streams, probably occurs in wetlands as well (R.A. Brandon, Southern Illinois University, personal communication). The lesser siren is permanently aquatic, inhabiting swamps, ditches, and sloughs (Smith 1961). All 21 species of anurans (frogs, tree frogs, and toads) that occur in Illinois (Morris et al. 1983, Hedges 1986) have an aquatic larval stage and rely on ponds, marshes, or seasonally flooded areas during the breeding season (Smith 1961). As adults some frogs and toads remain in or near ponds, marshes, or swamps, whereas others wander quite far from water (Smith 1961). 120 VEE AND... Temporary and seasonal wetlands are important to amphibians. Because their eggs and larvae are highly vulnerable to predation by fish, many amphibians that breed in water rely on wetlands in which standing water is not present long enough to support fish populations (Environmental Defense Fund and World Wildlife Fund 1992). Nineteen species of amphibians in Illinois depend upon temporary wetlands, such as vernal woodland ponds, flooded fields, or roadside ditches, for breeding (Morris 1991). Therefore, if the removal of legal protection from temporary and seasonal wetlands resulted in an increased loss of these types of areas, amphibian populations (and, conse- quently, the reptiles, birds, and mammals that feed upon them) would be adversely affected (Environmen- tal Defense Fund and World Wildlife Fund 1992). Amphibians in many parts of the world recently have undergone decreases in numbers and geographical ranges. The declines of some populations have been dramatic, and a few species, such as the gastric brooding frog of Australia and the golden toad of Costa Rica, have virtually disappeared in a short period of Figure 53. Historical and recent records of the swamp rabbit in Illinois. Source: Kjolhaug et al. 1987. time (Blaustein and Wake 1990; Phillips 1990, 1991; Wake 1991; Livermore 1992). The situation is complex because not all species of amphibians have experienced declines. Also, amphibian populations fluctuate greatly from year to year, and stochastic events could explain the local extirpation of populations when numbers are at low levels (Pechmann et al. 1991, Wake 1991). Many scientists, nonetheless, have concluded that there is a global problem facing amphibians, and that it is largely the result of habitat modification by humans (Blaustein and Wake 1990). No single factor can explain all the declines in amphib- ian populations. Some losses are directly attributable to habitat destruction, but in other cases amphibian populations have decreased in habitats that appear undisturbed (Blaustein and Wake 1990). More subtle forms of habitat modification are implicated in these declines. Because of their permeable skin and their exposure to both aquatic and terrestrial conditions, amphibians are especially susceptible to environmental stresses and can serve as bioindicators of these stresses (Blaustein and Wake 1990). Acid deposition is a problem for some species, including episodic acidifica- tion of wetlands or streams during the breeding season caused by snowmelt (Wyman 1990, Livermore 1992). Other factors that have been proposed as adversely affecting amphibian populations include changes in precipitation patterns (possibly a reflection of global warming), increased levels of ultraviolet radiation (a consequence of ozone depletion), pollution by pesti- cides or heavy metals, and the introduction of predators (Blaustein and Wake 1990, Phillips 1990, Wyman 1990). Little quantitative information exists on long-term trends in amphibian populations in Illinois, but the Midwest does not seem to be experiencing the drastic declines occurring elsewhere (C.A. Phillips, Washing- ton University, personal communication). Nonetheless, habitat loss has undoubtedly had an adverse effect on local populations within the state and has probably restricted the range of at least one species. Smith (1961) believed that the eastern newt originally occurred throughout Illinois but had disappeared from the central portion of the state because of deforestation and draining of prairie marshes. Of the 37 amphibian species that use wetlands, seven salamanders and five anurans have very limited distributions because Illinois lies at the edge of their ranges (Smith 1961, Conant and Collins 1991). In addition, the four-toed salamander occurs only as relict populations in scattered locations, only one native WETLANDS population of the silvery salamander is known in the state, and populations of the Illinois chorus frog are disjunct. These species would be especially vulnerable to continued loss of wetland habitat or detrimental changes in the environmental conditions of wetlands. Reptiles. Reptiles, as a group, are less dependent on water than are amphibians. Nevertheless, many reptiles are aquatic, including a large proportion of turtles and several snakes. Of the 60 species of reptiles that occur in Illinois (Morris et al. 1983), at least 47 species utilize or depend upon wetland habitats (Smith 1961; Conant and Collins 1991; R.A. Brandon,Southern Illinois University, personal communication; C.A. Phillips, Washington University, personal communica- tion; S.R. Ballard, Illinois Department of Conservation, personal communication) (Figure 41, Appendix 6). Most turtles in Illinois are aquatic or semi-aquatic, and 15 of the 17 turtle species in the state occur in wetlands (Smith 1961; R.A. Brandon, Southern Illinois Univer- sity, personal communication). Ten of these species are not restricted to wetlands and are also found in other aquatic habitats. The snapping turtle and common musk turtle, for example, are common in ponds throughout Illinois, but they also inhabit streams, rivers, and lakes. Eight species occur in marshes, sloughs, or swamps as well as streams, rivers or lakes (Smith 1961). The eastern mud turtle, Illinois mud turtle, and Blanding’s turtle, all rare in Illinois, occur only in wet meadows, marshes, sloughs, or ponds (Smith 1961). The very rare spotted turtle is found only in sedge meadows in Illinois (Herkert 1992). The terrestrial eastern box turtle inhabits floodplain and upland forests (Smith 1961). Only six species of lizard are known to occur in Illinois (Morris et al. 1983). Four of these—the eastern fence lizard, five-lined skink, broadhead skink, and ground skink—can occur in floodplain forests (Conant and Collins 1991; R.A. Brandon, Southern Illinois Univer- sity, personal communication; C.A. Phillips, Washing- ton University, personal communication). Twenty-eight of the 37 species of snakes in Illinois occur in wetlands (Smith 1961; Conant and Collins 1991; R.A. Brandon, Southern Illinois University, personal communication; C.A. Phillips, Washington University, personal communication; S.R. Ballard, Illinois Department of Conservation, personal commu- nication). Seven species of water snakes inhabit ponds, marshes, sloughs, and swamps (Smith 1961). The eastern and western ribbon snakes are semi-aquatic and seldom venture far from ponds, marshes, or swamps 121 WETLANDS (Smith 1961, Conant and Collins 1991). Garter snakes occur in a variety of habitats, including bogs and the edges of marshes or ponds (Minton 1972, Conant and Collins 1991). The mud snake is an inhabitant of swamps and sloughs in southern Illinois (Smith 1961). Other species of colubrid snakes that can be found in wetlands include the worm, smooth green, racer, brown, smooth earth, and eastern hognose snakes (Smith 1961; R.A. Brandon, Southern Illinois Univer- sity, personal communication). The great plains rat snake is typically an upland species but is included as a wetland species because it occurs in a marsh in Monroe County (R.A. Brandon, Southern Illinois University, personal communication). All four pit vipers use wetlands; the cottonmouth inhabits swamps and sloughs during the summer, the massasauga is an inhabitant of marshes and bogs, and the timber rattle- snake and copperhead sometimes occur in floodplain forest (Smith 1961). Snakes of other species may visit ponds or the edges of marshes or swamps to feed upon amphibians or drink. There are no long-term quantitative data on the abundance of reptiles in Illinois. The draining of prairie marshes in central Illinois is thought to have had an adverse impact on the distribution and abundance of reptiles. Blanding’s turtle was once probably abundant in the northern half of Illinois but in recent years has occurred as scattered colonies with a discontinuous distribution (Smith 1961). Similarly, the massasauga was probably common throughout the northern four-fifths of Illinois (Smith 1961). Both of these species have been placed on the Illinois Department of Conservation’s watch list. Fish. Wetlands also serve as breeding grounds for many species of fish. The status of fish populations in Illinois is addressed in the chapters on flowing waters and lakes and impoundments. Invertebrates. Invertebrates are the least conspicuous but most abundant animals in any wetland habitat, and they play an essential role in making plant energy available to other animals. Among the invertebrates present in Midwestern wetlands are protozoa, sponges, flatworms, worms, crustacea, mollusks (clams and snails), and insects. Although most of the insects are terrestrial, a significant number (about 10%) are adapted for living in water. Among the fairly common insects of wetlands are crawling water beetles, giant water bugs, water scorpions, dragonflies, and mayflies. In some types of wetlands, such as deep- and shallow-water marshes, mollusks are dominant and 122 form an important food source for fish and diving ducks. The presence of unionid mollusks is also a fairly reliable indicator of relatively clean, pollution-free water. Trend information for macroinvertebrate communities of lentic wetlands in Illinois is lacking, although some faunal studies of species groups are available. Macroinvertebrates are acknowledged as important components of wetland ecosystems; they are, for example, an essential food source for waterfowl and fish and are important in processing organic matter. Macroinvertebrate communities are certainly as different as wetlands themselves. Factors influencing macroinvertebrate communities include the predictabil- ity and seasonality of drying as well as the volume and depth of open water. Several faunal studies conducted in Illinois have addressed taxa that are important in wetlands, includ- ing mosquitoes (Ross 1947, Ross and Horsfall 1965) and horse flies and deer flies (Pechuman et al. 1983). In particular, mosquitoes are well known as nuisances and disease carriers. Mosquitoes in Illinois have been the subject of more than 400 scientific and popular papers in this century, and the control of pest species has cost millions of dollars (Baumgartner 1990). Over 60 species of mosquitoes are found in the state, but few are serious pests and not all bite humans. The habitat requirements of mosquito species vary greatly, and though most require wetlands for breeding habitat, some take advantage of artificial sites, such as water in tire piles, refuse heaps, and containers inside buildings. Threatened and Endangered Species Vertebrates. Forty-five percent (94) of the 209 federally listed threatened and endangered animal species are wetland-dependent or wetland-related (Feierabend and Zelazny 1987). Ninety-four species of vertebrates are listed as threatened or endangered in Illinois (Herkert 1992). The majority of these species (64%) either depend upon or utilize wetland habitats at least during one stage of their life cycle (e.g., larval development) or for specific functions (e.g., foraging) (Figure 54). The number of threatened and endangered vertebrate species dependent upon wetlands recorded in each county in Illinois since 1980 is shown in Figure 55 (Herkert 1992, Illinois Natural Heritage Database). Birds. Of the 43 species listed as endangered and threatened in Illinois, 30 are strongly associated with wetland habitats (especially during the breeding season), and the remaining 13 can use wetland habitats opportunistically throughout the year (Bohlen 1989, Herkert 1992, Illinois Fish and Wildlife Information System). The 30 species that are strongly associated with wetlands are listed in Table 8. These species may use one particular type of wetland habitat or several types to fulfill life history requirements; for example, the great egret (Figure 56) typically nests in floodplain forests but prefers to forage in shallow-water wetlands. Twenty-five species of endangered and threatened birds use shallow-water wetlands for nesting and foraging, 12 use floodplain forests for nesting, forag- ing, or resting, nine use deep-water wetlands and lakes to forage, and eight use other types of wetlands, such as sedge meadows, wet prairie, mudflats, sandbars, etc. (Bohlen 1989, Herkert 1992, Illinois Fish and Wildlife Information System) Habitat destruction or degradation is likely to be responsible for the decline of 23, and range reductions of 15, endangered and threatened bird species in Illinois (Herkert 1992). For example, since 1980, the black tern’s breeding range has decreased to four northeastern Illinois counties (Figure 57). From 1980 through 1989, black terns were observed at 19 wetlands in these four counties but nested at only nine of the sites (Heidorn et al. 1991) (Figure 58). Before 1985 this species had 77 nests in five wetlands, but after 1985 there were 50 nests in eight wetlands (Heidorn et al. 1991). Although the local distribution of black terns may appear to be increasing slightly, its population numbers are decreasing. As larger wetlands are fragmented or destroyed, black terns, like other wetland-dependent birds, must search for new and perhaps less suitable nesting sites that may not support large population numbers. Therefore, despite their mobility, wetland destruction and degradation may cause populations of endangered and threatened bird species to become small and scattered, thereby jeopar- dizing their continued existence in the state. Bald Eagles. Bald eagles have been present in what is now Illinois for thousands of years. The first docu- mented presence of eagles dates back 400 to 800 years based upon the remains of at least 16 bald eagles identified by Parmalee (1958) from Indian burial sites in Cahokia. The Illinois and Mississippi river flood- plains were once commonly used for nesting by bald eagles. Ridgway (1889) listed the bald eagle as a “summer resident of general distribution.” The eagle was considered a “more or less common” bird along the larger water courses. Historically, the bottomlands near the confluence of the Missouri, Ohio, and Missis- WETLANDS sippi rivers were major nesting areas for bald eagles (U. S. Fish and Wildlife Service 1986), and the large rivers and wetlands in and adjoining Illinois served as important winter habitat. Declines in the continental population—caused by factors such as habitat destruction, illegal shooting, secondary lead poisoning, increasing human use of formerly remote areas, and, more recently, pesticide contamination that resulted in poor reproduction—have been reflected in the small numbers of bald eagles observed in Illinois from the late 1800s until the mid- 1900s (Evans 1982). Postupalsky (1971) reported reproductive failure of two populations of bald eagles in Ontario associated with decreased eggshell thickness and residues in eggs of DDE, PCB, dieldrin, and mercury. These toxic chemicals caused one population to decline at a rate of 14-15% per year. However, with legal protection and the prohibition of certain pesti- cides, the nationwide number of bald eagles censused dramatically increased after the late 1970s and reached 13,869 in 1981 and 13,574 in 1990 (G.W. Kruse, Illinois Department of Conservation, personal commu- nication). There were between two and four bald eagle nests documented in Illinois between 1978 and 1987. In 1992, 17 bald eagle nests were recorded in Illinois, and 16 eaglets successfully fledged. Currently, the Mississippi River valley from southern Minnesota to southern Illinois is an important winter area for the endangered bald eagle (U.S. Fish and Wildlife Service 1986). Illinois, Missouri, and Arkan- sas host several hundred bald eagles each winter (U.S. Fish and Wildlife Service 1986). Millsap (1986) found that over 95% of the bald eagles observed during the 1979 to 1982 midwinter surveys occurred west of a line from Lake Michigan to the Mississippi delta and that more than 30% of the sightings occurred along and adjacent to the Mississippi, Illinois, and Missouri rivers. Although nesting of bald eagles in Illinois is now a rare occurrence, large numbers of eagles still winter in the state and concentrate along the large rivers. Aerial censuses conducted by the Illinois Natural History Survey during early January from 1957 to 1993 along the floodplains of the Illinois River and the central section of the Mississippi River bordering Illinois from Alton to Rock Island demonstrate the recovery of the bald eagle in North America (Figure 59). A total of 1,211 bald eagles were inventoried along these two river floodplains in January 1990, a noticeable increase from the low numbers present during the late 1960s. 123 WETLANDS O Don't use wetlands Use wetlands Number of Species Fish Amphibians Reptiles Birds Mammals Figure 54. Proportion of endangered and threatened vertebrate species in Illinois that are strongly associ- ated with wetlands. The number of bald eagles observed during the Illinois Natural History Survey inventories has decreased since 1990, but this decline has been a result of weather- related dispersion of the birds and does not reflect a population decline. The Illinois component of the Midwinter Bald Eagle Survey conducted by the National Wildlife Federation documented 1,539 wintering bald eagles in Illinois in 1990, 1,864 in 1991, and 2,025 in 1992. Double-crested Cormorants. Ridgway (1895) de- scribed the double-crested cormorant as a transient visitor in Illinois, arriving from the northern breeding areas in September and October and returning from their southern wintering areas along the Gulf Coast in March and April. The continental numbers of double- crested cormorants dramatically declined in the mid- 1900s. Postupalsky (1971) reported that residues of DDE, PCB, dieldrin, and mercury were associated with eggshell thinning and reduced reproduction of double- crested cormorants in Ontario. Postupalsky (1971) stated that cormorants were declining in number throughout the Great Lakes area. Since the early 1980s and more than a decade after the ban on DDT, cormorant populations have increased nearly 7% annually (Anonymous 1992). Double- crested cormorants have rebounded from a nationwide population of several thousand in the mid-1970s to approximately 235,000. This bird was nearly placed on the federal endangered species list in the late 1960s but now has become a nuisance to some aquaculturists and sport fishermen (Smith and Drieband 1991). 124 Figure 55. The number of threatened and endangered vertebrate species dependent upon wetlands in each county in Illinois, 1980 to the present. In Illinois, Lake Renwick and Bakers Lake in the northeastern part of the state host nesting populations of double-crested cormorants. These birds, which nest in association with heron colonies, are on the state’s endangered species list. Other nesting sites include Carroll County on the Mississippi River, Putnam and Peoria counties along the Illinois River, and Rend Lake in southern Illinois (Bohlen 1989). The peak numbers of double-crested cormorants recorded in the Illinois River and Central Mississippi River valleys during aerial inventories conducted by Illinois Natural History Survey during fall migration from 1966 to 1992 demonstrate the upward trend in the North American population of this species (Figure 60). The fall inventories documented fewer than 100 double-crested cormorants in both of these river valleys from 1966 to 1973. However, 5,195 double-crested cormorants were observed in the Illinois Valley in the fall of 1992, and 1,515 were recorded in the central Missis- sippi River region in 1986. WETLANDS Table 8. Status and habitats of the 30 Illinois endangered and threatened bird species that depend on or are strongly associated with wetlands. Shallow-water? wetland X Species Status* Pied-billed grebe Double-crested cormorant American bittern Least bittern Great egret Snowy egret Little blue heron Black-crowned night-heron Osprey Mississippi kite Bald eagle Northern harrier Red-shouldered hawk Yellow rail Black rail Purple gallinule Common moorhen Sandhill crane Piping plover Wilson’s phalarope Common tern Forster’s tern Least tern Black tern Short-eared owl Brown creeper Veery Swainson’s warbler Henslow’s sparrow Yellow-headed blackbird 1 KKK MK OK OK * * 1 PS MK KK OK OK OK OK OO * 19s MC? Mier Mier Ml coi coMceMs coi csMcolicolco Mia McvlcsMcolicoll coli collcoMecsMcoMcsMcoMlcoM esl collcolles| ~ KK mK MK Deep-water Floodplain wetland forest Other’ X X -- -- -- X -- X X -- X xX -- X X -- X X X X -- -- xX X xX xX xX -- -- xX -- xX X -- -- X -- -- X X a = x Be ae -- -- X -- -- X -- -- X X -- X xX re ae X -- X x i =f -- -- X Po 4 - = x a2 - x ue -- -- X * Status = E = state-listed endangered species; T = state-listed threatened species; E* = federally listed endangered species. » Shallow-water wetland = water < 2 ft deep. © Deep-water wetland = water > 2 ft deep. 4 Other = sedge meadows, wet prairie, mudflats, sandbars, etc. Mammals. Eight of the 10 endangered and threatened mammal species in Illinois use wetlands. These include two federally endangered species, the Indiana bat and gray bat, and two federal candidate species, the southeastern bat and Rafinesque’s big-eared bat (U.S. Fish and Wildlife Service 1991). The Indiana bat hibernates in caves or mines, but its summer roosts and maternity colonies are usually under the exfoliating bark of trees (Humphrey et al. 1977). In Illinois, roost trees used by Indiana bats have been found in both floodplain and upland forest, and these bats may preferentially feed in floodplain forests (Gardner et al. 1990, 1991). The gray bat uses caves year-round, but forages in floodplain forests (La Val et al. 1977). The southeastern bat typically roosts in caves or mines, but a maternity colony was discovered in the hollow base of a tupelo gum in Little Black Slough in Johnson County (Gardner et al. 1992). Rafinesque’s big-eared bats were also found roosting in a tupelo gum in this swamp (Gardner et al. 1992). Recent records for southeastern and big-eared bats along the Cache River and near Horseshoe Lake in Alexander County indicated the importance of forested wetlands as foraging habitat (Gardner et al. 1992). The southeastern and Rafinesque’s big-eared bats occur only in the southernmost counties of Illinois, which lie at the edge of their ranges (Hoffmeister 1989). The marsh rice rat is semi-aquatic and inhabits coastal marshes, freshwater marshes, wet meadows, and swamps (Wolfe 1982). In Illinois, this species has commonly been found in areas with herbaceous 125 WETLANDS Figure 56. The great egret, which typically nests in floodplain forests but prefers to forage in shallow- water wetlands. (Photo taken at Lake Renwick Heron Colony, Will County, by Joe Milosevich.) wetland vegetation, including lake margins and roadside ditches (Hofmann et al. 1990). The golden mouse is arboreal and occurs in shrubby or wooded areas with a dense, tangled understory of vines, in canebrakes, and along the edges of swamps (Linzey and Packard 1977). These two rodents are limited to the southern portion of Illinois. The main population of river otters in Illinois inhabits the backwaters of the Mississippi River and adjacent floodplain forests north of Rock Island; another population may be located at Little Black Slough (Anderson and Woolf 1984). The bobcat requires large tracts of relatively undisturbed habitat that includes upland forest, wooded bluffs, open fields, bottomland forest, and swamps (Hoffmeister 1989). Amphibians. All three species of amphibians that are listed as endangered or threatened in Illinois depend upon wetland habitats (Herkert 1992). The silvery salamander, a unisexual polyploid species, was discovered in Illinois in 1973, and its only native population occurs at Middle Fork Woods Nature Preserve in Vermilion County (Morris 1974, Herkert 1992). These animals inhabit a wooded upland and ravine but breed in a single vernal pool (Herkert 1992). The dusky salamander, whose range extends only into the southernmost portion of Illinois, inhabits seeps, springs, and rocky headwater streams (Brandon and Huheey 1979). The Illinois chorus frog is a fossorial species that inhabits open sandy areas in floodplains, such as the sand prairies along the Illinois River (Axtell and Haskell 1977). It depends upon ponds, marshes, flooded depressions in fields, and roadside ditches for 126 och} pre 1980 1980 to present Figure 57. Counties in which nesting black terns were found before and after 1980. breeding (Brown and Rose 1988). Because of its specific habitat requirements, the range of the Illinois chorus frog probably has always been limited to its present extent (Herkert 1992). Reptiles. Nine species of reptiles, three turtles and six snakes, are listed as endangered or threatened in Illinois (Herkert 1992). Seven of these species use wetland habitats (Smith 1961; R.A. Brandon, Southern Illinois University, personal communication). The spotted turtle inhabits sedge meadows in northeastern Illinois (Herkert 1992); elsewhere, it also occurs in ponds, bogs, and swamps (Conant and Collins 1991). Illinois lies at the western edge of the range of the spotted turtle, and it has been recorded in only Cook and Will counties (Smith 1961). The original spotted turtle colonies were presumably lost to urbanization, and the species is now restricted to Will County (Herkert 1992). The Illinois mud turtle is largely aquatic and occurs in sandy areas interspersed with permanent or semi-permanent ponds or sloughs (Smith 1961). Illinois mud turtle populations are disjunct from the main range of this more western species and are i aye oF, Ld a Pe aes 2) byes: bet on HA seal = Figure 58. Black tern nesting locations in northeastern Illinois, 1980 to 1989. Before 1985 this species had 77 nests in 5 wetlands, and after 1985 it had 50 nests in 8 wetlands. (Shown as pre-1985/post-1985) Source: Heidorn et al. 1991. —t— illinois River ——*— Mississippi River Numbers of Eagles 1955 1960 1965 1970 1975 1980 1985 1990 1995 Year Figure 59. Number of bald eagles (3-year moving average) aerially inventoried by the Illinois Natural History Survey in the Illinois and central Mississippi River regions during the annual Midwinter Survey, 1955, 1958 to 1993. WETLANDS —— Illinois River —‘— Mississippi River Fall Peak Numbers 1965 1970 1975 1980 1985 1990 1995 Year Figure 60. Peak numbers (3-year moving average) of double-crested cormorants aerially inventoried by the Illinois Natural History Survey in the Illinois and central Mississippi River regions during fall, 1966 to 1992. restricted to sand areas in northwestern and west-central portions of the state (Smith 1961, Herkert 1992). Mud turtle populations have declined over the past 30 years as a result of human alteration of sand areas and the draining of ponds and sloughs. Optimal habitat for the river cooter appears to be heavily vegetated sloughs and oxbows on the floodplains of large rivers (Moll and Morris 1991). Although always considered rare, the river cooter, currently known from only four Illinois counties, once ranged more widely along the Mississippi, Ohio, and Wabash rivers (Smith 1961, Herkert 1992) (Figure 61). The reduction of the river cooter’s range has probably been caused by the draining of swamps and oxbows and by channelization (Herkert 1992). The green water snake and broad-banded water snake inhabit swamps, marshes, and river sloughs (Conant and Collins 1991). Both species presumably have always been limited to the southernmost portion of Illinois (Smith 1961), but the number of known localities for the green water snake has declined (Smith 1961, Herkert 1992) and the broad-banded water snake may be extirpated from the state (Herkert 1992). The eastern ribbon snake is semi-aquatic and occurs in swamps, marshes, ponds, and streams (Conant and Collins 1991). Illinois lies at the edge of this species’ range; recent records are limited to four southern counties, but the species was formerly known from an additional two counties in southeastern Illinois (Herkert 1992). Although the great plains rat snake is typically an upland species that inhabits rocky wooded 127 WETLANDS hillsides, it occurs at Kidd Lake Marsh in Monroe County (R.A. Brandon, Southern Illinois University, personal communication). The range of this species barely extends into western Illinois (Smith 1961); once known to occur along the Mississippi River bluffs from Jersey to Randolph counties, it has recently been reported in only Monroe and Randolph counties (Herkert 1992). Fish. Twelve of the 29 endangered and threatened fish species in Illinois occur in wetlands or use them for spawning (Smith 1979; Page and Burr 1991; L.M. Page, Illinois Natural History Survey, personal communication). The alligator gar is an inhabitant of swamps, bayous, and lakes as well as sluggish pools and backwaters of large rivers (Page and Burr 1991). The cypress minnow occurs in swamps, cypress-lined oxbow lakes, and sluggish backwaters of streams (Smith 1979, Page and Burr 1991). The habitat of the bluehead shiner includes backwaters, oxbows, and sluggish pools (Page and Burr 1991); in Illinois it has been found primarily along the vegetated margins of Wolf Lake in Union County (Burr and Warren 1986). The spotted sunfish and bantam sunfish inhabit swamps and heavily vegetated ponds, lakes, and sloughs (Smith 1979, Page and Burr 1991). The Iowa darter occurs in well-vegetated lakes, sloughs, and low-gradient streams (Smith 1979). The larval stage of the least brook lamprey lives in spring-fed wetlands, quiet pools, and backwaters of streams, although the adults occur in clear riffles and runs of streams and small rivers (Page and Burr 1991). In addition, five species that are inhabitants of lakes or streams require quiet areas with dense emergent vegetation for spawn- ing and are, therefore, included as wetland species (L.M. Page, Illinois Natural History Survey, personal communication). These are the banded killifish, pugnose shiner, ironcolor shiner, blackchin shiner, and blacknose shiner. Comparing post-1950 records to pre-1905 records, Smith (1971) concluded that drainage of natural lakes, marshes, swamps, and sloughs associated with large rivers in Illinois had resulted in range reductions for 13 native fish species, including the following wetland species that have since been listed as endangered or threatened: banded killifish, pugnose shiner, blackchin shiner, blacknose shiner, spotted sunfish, bantam sunfish, and Iowa darter. According to post-1980 records, the ranges of some of these species appear to have been reduced further (Herkert 1992). The blacknose shiner, for example, was recorded from numerous locations throughout the northern two-thirds of Illinois prior to 1905 but from only eight counties 128 during the 1950s and 1960s (Smith 1971). Since 1980, this species has been found only in Lake County (Herkert 1992). The cypress minnow has probably always been limited to southern Illinois; even so, its range has been drastically reduced. Once collected (sometimes in large numbers) from seven locations in the Big Muddy River, Clear Creek, Cache River, and Horseshoe Lake drainages, this species now occurs only at two loca- tions along the Cache River and, perhaps, in Horseshoe Lake (Warren and Burr 1989) (Figure 62). A prime factor in the range reduction of the cypress minnow has been the drainage of wetlands for agriculture (Warren and Burr 1989). Two of the endangered and threatened wetland species of fish, the alligator gar and bluehead shiner, may already be extirpated from the state (Burr 1991). The alligator gar had been reported from the lower Missis- sippi, Big Muddy, Ohio, Wabash, Kaskaskia, and Illinois rivers and Horseshoe Lake in Alexander = = ye ie a K eat AE rat eZee ea RE = A eA Figure 61. Distribution of the state-endangered river cooter in Illinois before and after 1980. Source: Herkert 1992. County (Smith 1979), but it has not been found in Illinois since 1965 (Burr 1991). The major cause of its loss (or decline) has been channelization and impound- ment of rivers, modifications that eliminated much of their quiet backwater areas. The bluehead shiner, known only from springs at Pine Hills, Otter Pond, and Wolf Lake in Union County, has not been found since a chemical spill in Wolf Lake in 1974 (Burr and Warren 1986, Burr 1991). Invertebrates. Fifty-one invertebrates are listed as endangered or threatened in Illinois, including one snail, 33 freshwater mussels, 11 crustaceans, and five insects. Of these, only one mussel, two crustaceans (amphipods), and one insect are considered wetland species. The pondhorn mussel inhabits ponds, sloughs, and lakes (Herkert 1992). Two species of amphipods occur in shallow groundwater habitats such as seeps, springs, caves, and subsurface cavities in limestone and are known only from extreme southeastern Illinois (Herkert 1992). The Hine’s emerald dragonfly inhabits distinctive marsh communities in northeastern Illinois. Hine’s (Ohio) emerald dragonfly is named after its distinctive bright green eyes. Its strong flying ability as an adult enables it to capture and devour smaller insects, including pests such as mosquitoes and biting flies, on the wing. The dragonfly’s connection to a rare and localized type of wetland has threatened its populations. The species is now listed as endangered in the state of Illinois, is a candidate for federal listing by the United States Fish and Wildlife Service as endan- gered or threatened, and is listed as endangered by the International Union for the Conservation of Nature (U.S. Fish and Wildlife Service 1990, Cashatt 1991, Herkert 1992). Hine’s emerald dragonflies are cur- rently restricted to a few sites in Illinois and Door County, Wisconsin (Cashatt and Vogt 1992). In Illinois, the dragonflies are found only in specific habitats in the Des Plaines River watershed where calcareous water emerges from the contact zone between the overlying glacial till and the limestone bedrock and collects in shallow cattail marshes, wet meadows, or small streams (Figure 63) (Cashatt and Vogt 1990, Cashatt 1991, Cashatt et al. 1992). The breeding habitat requirements for this dragonfly are restrictive because the immature stage requires clean water in which to develop. The largest threat to the continued existence of this dragonfly is habitat destruction and fragmenta- tion caused by urban and industrial development. The Illinois sites are currently being threatened by a petroleum refinery, a sewage treatment plant, rock quarries, an electrical power plant, an asphalt plant, and a highway project (Cashatt and Vogt 1992). WETLANDS ONGOING WETLAND CHANGES Annual Rate of Loss Dahl (1990) estimated that in the conterminous United States at the time of Colonial America there were 221 million acres (89.5 million ha) of wetlands. The estimate of wetlands in the contiguous 48 states in the mid-1970s was 105.9 million acres (42.9 million ha) (Dahl and Johnson 1991). Between the mid-1950s and the mid-1970s, about 11 million acres (4.5 million ha) of wetlands were lost while 2 million new acres (810,000 ha) were created (Tiner 1984). Of the remaining wetlands, palustrine wetlands represented 94% (Frayer et al. 1983). Despite some slight gains in wetlands, principally as a result of construction of ponds, reservoirs, irrigation projects, and restoration, the recent nationwide trend in wetland acreage has been clearly downward. The average rate of wetland loss from the mid-1950s to the mid-1970s was 458,000 acres (185,350 ha) per year, NOT SPIL eae a aa © Historic population @ Recent specimens Figure 62. Locations of historic populations and recent specimens of the state-endangered cypress minnow in Illinois. Source: Warren and Burr 1989. WETLANDS DUPAGE a Cook County forest preserve State nature preserve or natural area Wetlands coded as marsh ONE INCH = 2.8 MILES Figure 63. Sites in Illinois where Hine’s emerald dragonfly occurs (1—Waterfall Glen Forest Preserve, 2—Black Partridge Woods Nature Preserve and environs, 3—Romeoville Prairie Nature Preserve, 4—-Long Run Seep Nature Preserve, 5—Lockport Prairie Nature Preserve, 6—McMahon Woods, Palos Park). Source: Cashatt and Vogt 1990, Cashatt at al. 1992. 96% (440,000 acres or 178,066 ha) of which repre- sented losses of palustrine wetlands (Frayer et al. 1983). Drainage for agricultural development was responsible for 87% of the recent wetland losses; urban development accounted for 8% and other development, 5%. Agricul- ture affected forested and emergent wetlands more than other types during this 20-year span (Tiner 1984). By the mid-1980s, wetlands occupied about 5% of the land area of the conterminous United States (Dahl and Johnson 1991). There were 103.3 million acres (41.8 million ha) of wetlands, 97.8 million acres (39.6 million ha) of freshwater wetlands, and 5.5 million acres (2.2 million ha) of coastal wetlands. Over 2.6 million acres (1.05 million ha) of wetlands were lost between the mid-1970s and the mid-1980s, an average 130 annual loss of approximately 290,000 acres per year (117,361 ha). This rate of loss was less than the rate of 458,000 acres per year (185,350 ha) found between the mid-1950s and the mid-1970s (Dahl and Johnson 1991). Conversion of wetlands to agricultural land use de- creased from 87% for the mid-1950s to the mid-1970s to 54% during the mid-1970s to the mid-1980s. The lower 48 states lost an estimated 53% of their original wetlands by the 1980s. Twenty-two states have lost at least 50% of their original wetlands, and 10 states in the Mississippi Flyway, including Illinois, Arkansas, Indiana, Iowa, Kentucky, Missouri, and Ohio, have lost 70% or more of their original wetland acreage (Dahl 1990). Rates of wetland loss are difficult to quantify, espe- cially with ever- changing federal and state programs and policies. Within this context, identifying the exact rate of loss for wetlands in Illinois is formidable. However, an approximation can be derived from the national trend, for which more data are available. According to the U.S. Fish and Wildlife Service, the national rate of wetland loss was approximately 0.5% annually during the mid-1950s to mid-1970s. A random survey of 10 county agricultural and environ- mental resource professionals in Illinois in 1990 indicated that the national rate of 0.5% annual loss of wetlands was consistent with losses they observed in their respective counties. The southern tip of Illinois appeared to have a loss rate well above the national average, the northwest corner of the state appeared to have a loss rate at or above the national average, and the rest of the state had a loss rate at or below the national average (T. Dahl, U.S. Department of the Interior, personal communication). This trend is based upon very limited information and is not statistically valid. However, it does indicate that wetland losses continue in Illinois, with some areas experiencing higher loss rates than others. Agricultural Loss An important factor in the demise of wetland resources in Illinois was the implementation of drainage and levee districts. The passage of a series of Swamp Lands Acts in 1849, 1850, and 1860 resulted in the destruction of many wetlands in the United States. With these Acts, Congress gave 65 million acres (26.3 million ha) of wetlands to 15 states and urged them to reclaim the land for agriculture and sell it (Steinhart 1990). The Swamp Lands Act of 1850 included Illinois. Under this Act, Illinois deeded the wetlands to the counties (Lockart 1980). In 1852, the Illinois General Assembly enacted legislation giving county courts jurisdiction over wetlands, and any funds obtained from the sale of these lands were to be primarily used for drainage projects (Lockart 1980). By June 1906, Illinois had claimed almost 4 million acres (1.6 million ha) of “swamp land” from the federal government, and approximately 82 million acres (33.2 million ha) were claimed by the 16 states named in the Swamp Lands Acts (Wright 1907). Although the first drainage district was organized before 1818, only 163,000 acres (65,965 ha) were in drainage districts in Illinois by 1879 (Illinois Tax Commission 1941). By 1880, the largest part of the agriculturally productive lands of Illinois had been tilled, but poor natural drainage in much of the low, flat areas hampered production. Following the pattern developed in other states, Illinois created quasi- governmental units, known as drainage districts, which WETLANDS had many powers, including the power of eminent domain, under the Levee Act of 1879 and the Farm Drainage Act of 1885 (Lockart 1980, Thompson 1988). The Levee Act allowed the formation of drainage and levee districts to facilitate the needs of landowners in the fertile bottomlands, whereas the Farm Drainage Act allowed the formation of drainage districts to the benefit of owners of wet upland soils (Thompson 1988). Organization of districts proceeded rapidly, with more than 1.5 million acres (0.6 million ha) incorpo- rated into new districts in Illinois during the 1880s (Illinois Tax Commission 1941). In Illinois, 5,454,000 acres (2,207,204 ha) of the state’s approximately 35.9 million acres (14.5 million ha) had been drained by organized districts by 1937, and an additional 4 million acres (1.6 million ha) had been drained by private enterprise (Illinois Tax Commission 1941, Sanderson et al. 1979) (Figure 64). By 1978, the total area of lands drained for agriculture in Illinois had increased slightly to over 9.7 million acres (3.9 million ha), or approximately 27% of the area of the state (U.S. Department of Commerce 1978). Drainage of wetlands in Illinois destroyed many valuable waterfow! areas, including over 200,000 acres (80,939 ha) of the Illinois River valley and over 400,000 acres (161,878 ha) of the Mississippi River floodplain, primarily from Rock Island to Cairo (Lockart 1980). The Sny Island Levee District alone incorporates over 100,000 acres (40,469 ha) in Pike, Adams, and Calhoun counties (Lockart 1980). Other river floodplains also were affected, including 144,000 acres (58,276 ha) leveed and drained along the Cache, Ohio, and Wabash rivers (Lockart 1980). By 1905 in the United States, an estimated 30 million acres (12.1 million ha) were drained (Donnan and Sutton 1960). Between 1940 and 1950, an estimated 1.5 million acres (0.6 million ha) a year were added nationwide to organized drainage enterprises (Stefferud 1958). There were more than 102 million acres (41.3 million ha) in organized drainage enterprises in 1960 in the United States (Donnan and Sutton 1960). In addition, an estimated 50 million acres (20.2 million ha) of farmland were drained by private or farm drainage, resulting in a total of 153 million acres (61.9 million ha) of artificially drained land (Stefferud 1958). Between 1940 and 1960, the U.S. Department of Agriculture subsidized the drainage of approximately 60 million additional acres (24.3 million ha) for agricultural purposes (Steinhart 1990). Artificially drained agricultural land under organized enterprises in 1980 totaled approximately 107.5 million acres (43.5 million ha) (Dahl 1990). Ww WETLANDS Urban Loss The loss and modification of wetlands as a result of urbanization is apparent in the nation and in Illinois. From the mid-1950s to the mid-1970s, urban develop- ment accounted for 8% of the wetland losses in the contiguous 48 states (Frayer et al. 1983). The loss of wetlands to urbanization continued in the United States between the mid-1970s and the mid-1980s (Dahl and Johnson 1991). In northeast Illinois, the Chicago District of the U.S. Army Corps of Engineers issued 372 wetland fill permits in 1992, compared with nine in 1983 (Dreher et al. 1988) (Figure 65). Most permit applications regarding wetlands and stream modifica- tion in the region of the Chicago District were granted, and the number of applications ranged from about 50 to 90 per year from 1982 to 1985 (Figure 66). FACTORS AFFECTING WETLANDS Although the loss of wetlands is of monumental importance, the biological, chemical, and physical degradation of wetlands by humans and the resultant decline in productivity and diversity of those wetlands remaining are also significant. Wetlands have been affected by many factors, including alteration of natural hydrological regimes (i.e., drainage, dams, channelization, reservoirs), agriculture, urbanization, and nonpoint pollution, especially sedimentation. Sedimentation Erosion is responsible for removing 201 million tons (182 million metric tons) of soil each year in Illinois (Illinois Department of Agriculture 1992). Approxi- mately 35% of the 32 million acres (13 million ha) of rural land in Illinois requires some form of soil erosion control treatment. However, in 1990, Illinois led the nation in the number of acres of cropland planted with conservation tillage systems, which were used on 37.3% of the state’s cropland. Illinois also led the country in no-till planting (2.6 million acres; 1.05 million ha) in 1990 (Illinois Department of Agriculture 1992). Nevertheless, sedimentation has been a major factor in the degradation of wetlands, especially in the upper Midwest. Illinois, lowa, Minnesota, Missouri, and Wisconsin together represent only about 15% of the hydrologic area of the entire Mississippi River basin but produce about 40% of all the sediment originating from cropland in the basin (Peterson 1991). Further- more, about 55% of the land in these five states is Figure 64. Organized drainage and levee districts in Illinois prior to 1941 (Illinois Tax Commission 1941). cropland, as compared with a national average of 18% (Peterson 1991). Although erosion rates have been reduced in recent years, the rate of erosion in these five states was 32% above the national average (Peterson 1991). Sedimentation is the primary factor causing degrada- tion of many wetlands in agricultural areas. In Illinois, the proliferation of land planted in row crops, princi- pally soybeans, in the past half century was conducive to increased rates of sedimentation in the Illinois River valley (Bellrose et al. 1983). The increase in the amount of land planted in row crops, which do not protect the soil from wind and water erosion as well as small grains (wheat) and permanent cover (pasture, hay crops), was accompanied by the common practice of fall tillage with the moldboard plow. Harvested cornfields subjected to tillage with the moldboard plow in Illinois left only about 5% of crop residue and virtually no waste grain for wildlife (Warner et al. 1985). Consequently, with these changes, rates of sedimentation greatly increased. 400 % 300 E a =0n200 | = Ss oO OO [e} z 0 1983 1964 1985 1986 1992 Year Figure 65. The number of wetland fill permits issued by the Chicago District of the Corps of Engineers, 1983 to 1986 and 1992. Source: Dreher et al. 1988. M Denied OO Withdrawn —) Issued Number 1982 1983 1984 1985 Year Figure 66. Permit decisions of the Chicago District of the Corps of Engineers, 1982 to 1985. Source: Dreher etal. 1988. WETLANDS In the 1970s, the Illinois River received an estimated 27.6 million tons (25 million metric tons) of sediment per year; approximately 15.4 million tons (14 million metric tons) of sediment was deposited in the valley, and the remainder was transported to the Mississippi River (Lee and Stahl 1976). Sedimentation affects wetlands by deposition, by increasing turbidity, which reduces light penetration necessary for photosynthesis in submerged aquatic vegetation, and by creating soft bottoms, which preclude the ability of wetland plants to remain rooted (Bellrose et al. 1979, 1983; Havera and Bellrose 1985). With the loss of aquatic plants as a result of sedimentation and other factors, the integrity of the wetland systems and the quality of waterfowl habitat in the Illinois Valley were significantly dimin- ished (Havera and Bellrose 1985). The “early warning” indicators of the degrading effects of sedimentation on aquatic habitats are now appearing in the upper Mississippi River. WETLAND PROGRAMS There are numerous federal, state, local, and private programs that address wetlands and wetland-related issues in Illinois (Table 9). These programs include both regulatory and nonregulatory mechanisms, such as acquisition, planning, education, restoration, and technical assistance, and vary in their relative impor- tance as wetland protection mechanisms. Several programs have important effects, both positive and negative, on wetlands in Illinois. Illinois has accomplished an important step in main- taining an adequate wetland base. The Interagency Wetland Policy Act, enacted in 1989, established a goal of no overall net loss of existing wetlands or their functional value in Illinois as a result of state and state- supported activities. This act also directs state agencies to preserve, enhance, and create wetlands in order to increase the quality and quantity of the state’s wetland resource base. WETLAND CREATION/RESTORATION Federal and state governments have historically provided incentives to destroy wetlands. With in- creased knowledge and appreciation of the value of wetlands, however, a regulatory framework that emphasizes avoiding or minimizing impacts to wet- lands is now in place, and the rate of wetland drainage and conversion has slowed. Furthermore, wetland restoration and creation activities have contributed to 133 —_____. WETLANDS ameliorating the effects of unavoidable loss in wetland acreage. At this time, however, many aspects of the concepts and methods for creating and restoring wetlands are unknown. Simply defined, wetland restoration involves returning a disturbed or severely altered wetland to a state similar to its pre-existing condition. Much of the agricultural land in central Illinois, for example, includes ideal locations for restoration. This land often possesses a sufficient source of groundwater or surface water, favorable topography, wetland soil, and a reservoir of ungerminated seeds of wetland plants in the soil, and the land would revert to its former wetland state if field tiles were plugged and levees were removed. Alternatively, wetland creation is the construction of a wetland in an area that historically did not support a wetland. Because the essential components of wetlands must be artificially produced in this process, created wetlands are less likely to replicate the functions and values of a natural wetland. Wetlands are restored or created for both regulatory and nonregulatory purposes. In the regulatory context, many wetlands have been restored or created to compensate, or mitigate, for wetland losses permitted by the Corps of Engineers. The Corps usually requires mitigation as a condition for allowing certain activities, such as the dredge or fill of wetlands, that are restricted in Section 404 of the Clean Water Act. Nonregulatory purposes for restoration and creation include providing wildlife habitat and storm-water storage. Examination of available information on wetlands restored or created as mitigation required under Section 404 regulations may suggest the direction of wetland restoration and creation overall. For example, in 1991, the Corps of Engineers received about 15,000 Section 404 permit applications nationwide. Approximately 10,000 permits were granted, 30% of the applications were withdrawn or qualified under a general permit, and 5% of the applications were denied. Trends and patterns in Section 404 permit information were examined for Oregon for 1977 through 1987, for Washington for 1980 through 1986 (Kentula et al. 1992), and for Louisiana, Alabama, and Mississippi (Sifneos et al. 1992a) for 1982 through 1986, as well as for Texas and Arkansas (Sifneos et al. 1992b). In 13 counties in the South Florida Water Management District, projects examined were completed between 1987 and 1991 (Erwin 1991); in Wisconsin, 1988 data 134 covering federal, state, and county permits were considered for seven counties (Ott 1990). The fundamental element of any wetland restoration or creation project is the overall goal or intended purpose for the restored or created wetland. A goal of many of the created or restored wetlands considered in the aforementioned state studies was to replace functions lost from the destroyed wetlands. Wildlife and fisheries habitat, flood storage, and food chain support were common functions affected; however, these functions were not necessarily replaced in the created wetlands. Often, the functions of the original wetlands were unknown. Specified goals for about two-thirds of the permits examined in Florida were limited to acreage and desired habitat; 15% of the permits stated no goals. Fifty-six percent of the permits issued in Wisconsin fully complied with the requirements. Only 10% of the projects in Florida completely satisfied permit goals; another one-third partially fulfilled the requirements. An obvious trend observed in these states was an increase in the number of permits issued. Also, the size of mitigation projects decreased over the period. In Oregon and Washington, more than 50% of wetlands created or destroyed were < | acre (0.40 ha). In Louisiana, 63% of compensation wetlands and 59% of the wetlands affected were < 12.5 acres (5.0 ha). Similar results were noted in Texas. In Florida, the size of created and restored wetlands varied by the type of project, ranging from 0.1 acre (0.04 ha) for a commer- cial project to 195.2 acres (79 ha) for an agricultural project. In Louisiana, 81% of the permits required compensation in area equal to the loss. The number of wetland acres destroyed and created in the states studied, based on available Section 404 permit infor- mation, is shown in Figure 67. Although some gain in the number of wetland acres occurred in Alabama, 89% of the increase resulted from one permit. A greater number of wetlands discussed in the state reports were replaced in-kind (i.e., as the same wetland type) than out-of-kind. In-kind compensation generally resulted in the gain or maintenance of wetland acreage, but acreage decreased when compensation was out-of- kind. In some states, such as Wisconsin, many ponds were created when other types of wetlands were destroyed. Most of the destroyed and of the compensa- tory wetlands in the states studied were located in urban areas. Details on Section 404 permits for a small part of Illinois have been recently compiled, and trends are WETLANDS ____ Table 9. Important federal, state, local, and private wetlands programs in Illinois (adapted from Havera 1992 and Hubbell et al. 1993). Program Federal Executive Order #11990 Farm Bill—Conservation Reserve Program Farm Bill-Swampbuster Migratory Bird Conservation Fund North American Waterfowl Management Plan North American Wetland Conservation Act National Wetlands Inventory Pittman-Robertson Wildlife Restoration Act Clean Water Act- Section 404 Fish and Wildlife Private Lands Initiative Environmental Management Program State Federal Clean Water Act— Section 314 Federal Clean Water Act— Section 319 Farmland Assessment Act Illinois Drainage Code Act Mechanism Federal directive Acquisition, incentive- disincentive, management Incentive-disincentive Acquisition Acquisition, planning, funding, management Acquisition, funding, management Technical assistance Acquisition, funding, management, restoration Regulation Management, restoration, incentive-disincentive, technical assistance Management, funding Management Management Incentive-disincentive Regulation Effect Positive Potential/ positive Potential/ positive Positive Positive Positive Neutral/ positive Positive Positive Positive Positive Positive Positive Potential/ positive Negative Description Requires each federal agency to minimize the destruction, loss, or degradation of wetlands, and to preserve and enhance the natural and beneficial values of wetlands in implementing agency responsibilities. Discourages landowners from farming highly erodible land for 10 or 15 years; requires a soil conservation plan to receive annual payments. Discourages the conversion of wetlands on agricultural land by denying federal farm subsidies. Finances acquisition of land for the national wildlife refuge system. In addition, easements or fee-simple title can be acquired for wetlands for use as federal waterfowl production areas. Provides funding for protection, enhancement, or restoration of wetlands that are important to waterfowl and other migratory birds. States, private groups, or individuals can receive matching grants for wetland conservation projects if the projects further the goals of the North American Waterfowl Management Plan. Provides a detailed database of existing wetlands for research and other purposes. The Illinois portion was completed in the mid-1980s. Provides for the acquisition, restoration, and management of land for wildlife, including wetlands. Requires permits for regulation of non-point source discharges of dredged or fill material into wetlands. Encourages wetland restoration of converted or degraded wetlands on private lands. The Habitat Rehabilitation and Enhancement Project element of the Environmental Management Plan provides several million dollars for a minimum of 10 years to improve wetlands on public areas in the Upper Mississippi River System. Identifies the condition of all publicly owned fresh- water lakes. Also attempts to control pollution and restore water quality. Allows Illinois the authority to assess non-point water pollution sources and introduce management programs to control pollution. Allows farmers and landowners to receive property tax relief for wetlands and certain other habitats. Provides broad drainage regulations for agricultural, sanitary, or mining purposes. Also organized the operation of drainage districts. —_______ WETLANDS Program Illinois Endangered Species Act Interagency Wetland Policy Act Natural Areas Fund Rivers, Lakes, and Streams Act Soil and Water Conservation District Act— Section 22.02(a) State Migratory Waterfowl Fund Wildlife Habitat Endowment Fund Local Local ordinances - critical habitat - subdivision - zoning Parks and open space programs Stormwater management Tax incentives— property and income Water quality programs Private Ducks Unlimited— M.A.R.S.H. The Nature Conservancy Open lands projects 136 Mechanism Regulation Regulation Acquisition Regulation Acquisition Acquisition Acquisition Regulation, planning, acquisition Acquisition Regulation Incentive-disincentive Acquisition Acquisition Acquisition Acquisition, restoration, management Effect Potential/ positive Positive Positive Potential/ positive Potential/ positive Positive Positive Potential/ positive Positive Potential/ positive Potential/ positive Positive Positive Positive Positive Description Provides protection for threatened and endangered species within Illinois. Promotes no overall net loss of wetlands or their functional value as a result of state-supported activities. Provides for the acquisition and stewardship of natural areas, including wetlands. Provides for some protection of wetlands in floodplains. Land use changes within a county or municipality must be reviewed by the appropriate Soil and Water Conservation District. Provides funds for improvement of waterfow! habitat in Illinois and Canada and implementation of the North American Waterfowl Management Plan. Provides an endowment for the purpose of maintaining and acquiring high-quality wildlife habitat, including wetlands. Local ordinances can affect wetlands protection and management within the jurisdictional unit of government. Local government has the authority to acquire land as necessary. Land set aside for parks or open space can include wetlands or can provide protection for wetlands. County codes allow for management and mitigation effects of urbanization on stormwater drainage in metropolitan counties controlled by the Northeastern Illinois Planning Commission. Tax incentives can benefit landowners who protect wetlands. Taxes can be reduced for certain land uses. Local units of government, through the municipal and county codes set forth by the state, have the right to institute water quality standards within their jurisdiction. These programs can protect wetlands by controlling degrading pollution sources. The primary focus is the development, restoration, and management of wetland areas for waterfowl habitat. A national organization that preserves the diversity of land in the United States. The group also works with state agencies to identify ecologically significant areas. Wetland acquisition projects can provide good habitat while allowing private ownership. Private acquisition is often more expedient than governmental acquisition. WETLANDS Program Mechanism Effect Description Property tax maintenance _Incentive-disincentive Positive Landowners can take certain tax deductions by participating in conservation programs that affect wetlands. Regional plans— Planning Positive Heartland Water Resources Council is a not-for-profit Heartland Water venture on the Illinois River. Resouces Council Special area plans Planning Positive Special area plans help manage natural resources - Cache River - Cypress Creek similar to those described in other states. The number of wetland acres lost during fiscal years 1991, 1992, and 1993 in the St. Louis District of the Corps of Engineers as a result of individual permits was 63.3 (25.6 ha), 58.4 (23.6 ha), and 100.2 (40.6 ha), respec- tively, while the number of acres gained was 218 (88.2 ha), 121.5 (49.2 ha), and 505.7 (204.7 ha), respectively (K. Meldrum, Regulatory Branch, St. Louis District, Corps of Engineers, personal communication). The number of nationwide #26 permits, which regulate discharges of dredged or fill material into headwaters and isolated waters, issued by the Chicago District of the Corps of Engineers has been increasing. Addition- ally, in the Chicago District, 379 Section 404 nation- wide permits relating to wetlands were issued during fiscal year 1992, and 129 permits were issued during the first half of fiscal year 1993 (M. Machalek, Construction-Operations Division, Regulatory Branch, Chicago District, Corps of Engineers, personal commu- nication). Permits were issued for the filling of 91 acres (36.8 ha) of wetlands in the Chicago District by March 1993; mitigation efforts have resulted in the creation of 93 acres of wetlands (37.6 ha). Also in the northeastern part of Illinois, the Illinois Department of Transportation has been responsible for affecting 30.7 wetland acres (12.4 ha) and creating nearly 70.5 acres of wetlands (28.5 ha) since 1989, and an additional 33.8 acres (13.7 ha) are currently under construction as compensation for loss of 20 acres (8.0 ha) (D. Niemann, Bureau of Programming, Illinois Department of Transportation, District 1, personal communication). Wetlands have also been created and restored for nonregulatory purposes throughout Illinois for many years. Governmental agencies involved in this activity include the Illinois Department of Conservation and the U.S. Soil Conservation Service. The Department of Conservation has built wetlands for waterfowl manage- ment and wildlife habitat since the 1940s. Recent Department restoration and creation activity has occurred at Horseshoe Lake, Castle Rock, Moraine within a specific area and provide for research and management efforts. Hills, and Illinois Beach state parks. Other wetlands were developed in subimpoundments and associated areas as a consequence of the construction of reservoirs by the Corps of Engineers, primarily in the 1960s and 1970s. The U.S. Fish and Wildlife Service private lands initiative through the Partners for Wildlife Program, the North American Waterfowl Management Plan, and the 1985 and 1990 Farm Bills in conjunction with Illinois Department of Conservation have resulted in restoration of 73 wetlands in Illinois totaling 1,378 acres (558 ha) since 1987 and easements on an addi- tional 28 sites totaling over 1,000 acres (405 ha) (Allen 1992). Much of the wetland work by the Soil Conservation Service has been accomplished only recently or is still in a planning stage. Non-discharge-system wetlands constructed for water quality improvement have been a major focus and are important for treating both agricultural wastes and public water supplies. Two current projects include an experimental study on the upper Embarras River and a water quality improvement wetland for Lake Bloomington. A total of 421 acres (170 ha) of wildlife shallow ponds and 16,381 acres (6,632 ha) of bottomland wetlands and floodplain scour (where more than half of the area must be planted to trees) have been created in Illinois (G. Barickman, Soil Conservation Service, personal communication). Even though the number of acres of restored and created wetlands appears to balance current wetland loss, most of these wetlands have been formally inspected only recently to determine whether they are actually fulfilling their intended purpose and function- ing as natural wetlands. Wetland monitoring involves examining various components of the system, such as water quality, vegetation, invertebrates, fish, mammals, or birds. The extent to which these parameters meet the stated goals determines whether the restored or created wetland is successful or is progressing toward success. Monitoring also allows early detection of any problems 137 —_____. WETLANDS 3000 fH Acres destroyed Acres created 2000 Number of Acres 1000 OR WA LA AL MS TX AR FL State Figure 67. Number of wetland acres destroyed or created in various states, based on Section 404 permit information. Source: Erwin 1991, Kentula et al. 1992. that might occur, which subsequently can be addressed in a timely manner. This type of corrective manage- ment increases the likelihood that the wetland will function more like a natural wetland. Monitoring of restored or created wetlands in various states for compliance with Section 404 often has been inadequate. In the Pacific Northwest (Kentula et al. 1992) and in Texas (Sifneos et al. 1992b), about half of the sites studied were visited at least once; however, there has been no indication that these wetlands were actually fulfilling their intended purpose. In Louisiana, only 10% of projects were inspected (Sifneos et al. 1992a), and in Arkansas no monitoring was required (Sifneos et al. 1992b). Monitoring was required in all but one of the 40 projects studied in Florida, but only 15 projects were monitored sufficiently, and 15 projects were not moni- tored (Erwin 1991). Current wetland evaluation methods emphasize vegetation as an indicator of wetland development. One method of assessing vegetation within the Chicago region suggests natural quality (Swink and Wilhelm 1979) and has been used to verify progress toward project goals and the success of establishing native plant communities in restored or created wetlands (Wilhelm and Wetstein 1992a, 1992b). In this method, a numeric value, called the coefficient of conservatism, indicates how limited a native plant is to a:particular 138 —t}— Restored wetland, West unit —®— Restored wetland, East unit —%— Natural wetland Number of Native Species 1989 1990 1991 1992 Year Figure 68. Number of native species present in two units of a restored wetland in Kane County, 1989 to 1992, compared to the number of native species in the original natural wetland. Source: Wilhelm and Wetstein 1992b. plant community or set of environmental conditions. A value is assigned to each species and is used to calculate a natural quality index. The index serves as a measure of the floristic integrity of each site; the greater the conservatism of the species and the number of conservative species in a given area, the higher the natural quality (G. Wilhelm, unpublished information). The development of an ecosystem is a complex process, one that is extremely difficult to reproduce artificially. Consequently, despite the efforts to alleviate wetland loss, evidence has not yet demon- strated that restored or created wetlands adequately function as natural wetlands. Often, designs of wetland restoration or creation projects do not account for the spatial context for the new wetland. Wetlands are dynamic systems, inexorably linked to the adjacent uplands in the watershed. The quality of the uplands will affect the quality and amount of water received by the wetland, in turn influencing the type and quality of the resulting wetland community. Because of this unbreak- able link between upland and wetland habitats, the most successful wetland restoration and creation projects involve restoration of adjacent upland buffer zones to native plant communities, such as prairies and forests. In addition, in restored or created wetlands, relatively few native species are available to colonize and form stable natural communities (G. Wilhelm, unpublished information). These more conservative species often have particular hydrologic, water quality, and soil pH requirements for germination and growth; they may also require management such as annual burning (G. Wilhelm, unpublished information). Such specific conditions are extremely difficult to duplicate. Conse- quently, the native floristic diversity of the resulting community often does not match that of a natural wetland (Wilhelm and Wetstein 1992b) (Figure 68). Even when more conservative species are planted to boost the floristic quality, less than half may appear (Wilhelm and Wetstein 1992a) (Figure 69). Species with higher coefficients of conservatism may not grow (Figure 70) (Wilhelm and Wetstein 1992a). At best, 40% of the species planted are usually expected to grow in wetlands that have been designed and managed well—i.e., planted with appropriate species and burned annually (Wilhelm and Wetstein 1992b). Other failures were caused by an inadequate understand- ing and implementation of hydrology (the study of the role of water in the system), inappropriate plant species chosen for the site, or unsuitable substrates or soils. Failure with many wetland mitigation projects occurred because a contractor did not follow specifications or the Corps of Engineers did not check on the contractor’s compliance and progress (R. Theriout, Corps of Engi- neers Waterways Experiment Station, personal commu- nication). @ Species planted Species recruited Number of Native Species Swale 1E Swale2 Swale4 Swale5 Swale6 Figure 69. Number of native species planted and number of these species recruited in created wetlands (swales) after four years in Lake County. Source: Wilhelm and Wetstein, 1992a WETLANDS More information about these complex wetland systems is needed for restoration and creation. Knowledge about natural systems concerning aspects such as hydrology can be used to improve current design. Additional information gained from the monitoring of restored or created wetlands is essential to predicting the outcome of commonly used restoration and creation methods. Although natural wetlands are self-sustaining systems, more intensive management may be required to maintain the human-influenced restored or created wetlands. One example of current research in Illinois is the Des Plaines River Wetlands Demonstration Project. This project is a living laboratory designed to provide scientists with research opportunities for evaluating and quantifying how riverine wetlands affect water quality, mitigate flooding, and provide wildlife habitat (Wetlands Research, Inc. 1992). Hydraulically controlled experi- mental wetlands have been constructed on abandoned farm fields and gravel pits on a 450-acre (182-ha) site in northeastern Illinois in the floodplain of the Des Plaines River. Based on findings from research studies of the natural processes of aquatic systems, the project will develop procedures for design and management that will enable scientists and engineers to reconstruct multi- functional wetlands along rivers. The Des Plaines River Wetlands Project is a result of the efforts of Wetlands Research, Inc., which was —& Species planted El Species recruited Coefficient of Conservatism Swale 1E Swale2 Swale4 Swale5 Swale6 Figure 70. Mean coefficient of conservatism of native species planted and recruited after four years in restored wetlands (swales) in Lake County, 1989 to 1992. Source: Wilhelm and Wetstein, 1992a 139 WETLANDS formed in 1983 as a joint venture between the Lake County Forest Preserve District and the Openlands Project. Wetlands Research, Inc. is responsible for site management, research coordination, and project administration. The research work is conducted by staff and students of several universities, personnel from state agencies and private consulting organizations, and individual scientists and engineers. PLANNING EFFORTS Illinois Wetland Conservation Strategy The U.S. Environmental Protection Agency initiated a program to assist states, including Illinois, in their wetland efforts by providing funding for a variety of purposes. In Illinois, the major emphasis in the program has been the development of the Illinois Wetland Conservation Strategy (IWCS). This strategy serves as a long-range blueprint to guide a broad spectrum of wetland protection initiatives. The Illinois Department of Conservation executed a contract with Illinois Natural History Survey to assist in the develop- ment of the IWCS. In addition, three other planning efforts have been established: the Strategic Planning Process, the Conservation Congress, and the Land Use and Water Resources Priorities Task Force. The IWCS was divided into two phases to complement the other three planning efforts. Phase 1 of the IWCS, completed 30 April 1993, is designed to incorporate the recommendations from the three planning efforts. Within this initial phase, an assessment of current wetland programs, a discussion of the status of the resource, and a general identification of necessary program changes will be addressed. Phase 2 will provide a detailed assessment of the general recom- mendations identified in Phase 1. In Phase 2, the pros and cons of each general recommendation will be examined, priorities for action will be identified, and an outline describing the implementation of those priorities will be established. RESEARCH NEEDS Wetland research requires a long-term, interdiscipli- nary commitment because of the complex nature of the wetland environment and the natural variability of the climatic and hydrologic conditions that influence the range of data that can be collected over a short period 140 of time. Several answers are needed regarding many aspects of Illinois wetlands. Wetland subjects for which more information is necessary include: 1. Wetland quality, quantity, and distribution ¢ An assessment of the quality of the wetlands remaining in Illinois Periodic updates of the amount and distribution of wetlands in Illinois Effects of sediment, nutrients, and other pollutants on wetlands Methods for managing excessive sediment deposited in wetlands Effects of land-use practices on hydrology and wetlands in watersheds 2. Function and values of wetlands Information regarding the various functions of wetlands Information on the cumulative extent and type of functions of many small wetlands and their effects on the nearby environment Effects on flooding relative to the size and type of wetlands Sediment, nutrient, and pollutant trapping capacity of wetlands Refined economic estimates for the values of wetlands Surface water/groundwater relationships (both quantity and quality) related to wetland values 3. Wetland fauna ¢ Long-term population data in Illinois for a variety of wetland mammals, such as muskrats, beaver, and mink ¢ Long-term population data on amphibians and reptiles in Illinois Definition of relationships between the numbers of certain waterbird and other animal populations and various types of wetlands in Illinois 4. Mitigation, restoration, and creation of wetlands * Methods, monitoring, and economic and biological results for creation of wetlands * Methods, monitoring, and economic and biological results for restoration of wetlands LITERATURE CITED Allen, J. 1992. Promoting partnerships. Outdoor Highlights 20:4—S. Anderson, E.A., and A. Woolf. 1984. River otter (Lutra canadensis) habitat utilization in northwestern Illinois. Unpublished report submitted to Illinois Department of Conservation. 90 p. Anderson, W.L. 1991. Preliminary results of the 1990 Illinois Waterfowl Hunter Survey. Illinois Depart- ment of Conservation. 22 p. Anonymous. 1992. Cormorant come-back sparks controversy on Lake Ontario. Ecology USA 21:158. Axtell, R.W., and N. Haskell. 1977. An interhiatal population of Pseudacris streckeri from Illinois, with an assessment of its postglacial dispersion history. Chicago Acad. Sci. Nat. Hist. Misc. 202:1-8. Barbour, R.W. and W.H. Davis. 1969. Bats of America. University Press of Kentucky, Lexing- ton. 286 p. Barnes, R.M. 1909. They are gone. Oologist 15(8): 113-116. Baumgartner, D.L. 1990. A condensed history and comprehensive bibliography of mosquito (Diptera: Culicidae) research and control in Illinois. Pro- ceedings of the Illinois Mosquito and Vector Control Association 1:57—73. Bellrose, F.C., F.L. Paveglio, Jr., and D.W. Steffeck. 1979. Waterfowl populations and the changing environment of the Illinois River valley. Illinois Natural History Survey Bulletin 32:1-54. Bellrose, F.C., S.P. Havera, F.L. Paveglio, Jr., and D.W. Steffeck. 1983. The fate of lakes in the Illinois River valley. Illinois Natural History Survey Biological Notes No. 119. 27 p. Bent, C., ed. 1877. History of Whiteside County, Illinois, from its first settlement to the present time with numerous biographical and family sketches. Morrison, Illinois. 536 p. Benyus, J.M. 1989. Northwoods wildlife: a watchers guide to habitats. Northword Press, Minoqua, Wisconsin. 453 p. Blaustein, A.R., and D.B. Wake. 1990. Declining amphibian populations: a global phenomenon? Trends in Ecology & Evolution 5:203-204. Bohlen, H.D. 1989. The birds of Illinois. Indiana University Press, Bloomington. 221 p. Bowles, M.L., J.B. Taft, E.F. Ulaszek, D.M. Ketzner, M.K. Solecki, L.R. Phillippe, A. Dennis, P.J. Burton, and K.R. Robertson. 1991. Rarely seen WETLANDS endangered plants, rediscoveries, and species new to Illinois. Erigenia 11: 27-51. Brandon, R.A., and J.E. Huheey. 1979. Distribution of the dusky salamander, Desmognathus fuscus (Green), in Illinois. Chicago Acad. Sci. Nat. Hist. Misc. 205:1—7. Brown, L.E., and G.B. Rose. 1988. Distribution, habitat, and calling season of the Illinois chorus frog (Pseudacris streckeri illinoensis) along the lower Illinois River. Illinois Natural History Survey Biological Notes No. 132. 13 p. Bratton, S.P. 1982. The effects of exotic plant and animal species on nature preserves. Natural Areas Journal 2:3-13. Burr, B.M. 1991. The fishes of Illinois: an overview of a dynamic fauna. Illinois Natural History Survey Bulletin 34:417-427. Burr, B.M., and M.L. Warren, Jr. 1986. Status of the bluehead shiner (Notropis hubbsi) in Ulinois. Transactions of the Illinois State Academy of Science 79:129-136. Burton, T.M., and G.E. Likens. 1975. Salamander populations and biomass in the Hubbard Brook Experimental Forest, New Hampshire. Copeia 1975:541-546. Cashatt, E.D. 1991. A vulnerable species: the Ohio emerald dragonfly. The Living Museum 53:29-30. Cashatt, E.D., and T.E. Vogt. 1990. The Illinois 1990 status survey for the Ohio emerald dragonfly (Somatochlora hineana) Williamson. Submitted to the U. S. Fish and Wildlife Service, Office of Endangered Species. Cooperative agreement No. 14-16-0003-89-931. 20 p. Cashatt, E.D., and T.E. Vogt. 1992. The Illinois 1991 Survey for the Hine’s emerald dragonfly (Somatochlora hineana Williamson). Submitted to the U. S. Fish and Wildlife Service, Office of Endangered Species. Cooperative Agreement No. 14-16-0003-89-931. 13 p. Cashatt, E.D., B.G. Simms, and J.R. Wiker. 1992. Illinois 1992 critical habitat and recovery investi- gations for the Hine’s emerald dragonfly. Submit- ted to the U.S. Fish and Wildlife Service, Chicago Metro Wetlands Office. 31 p. Chabreck, R.H. 1978. Wildlife harvest in wetlands of the United States. Pages 618-631 in P.E. Greeson, J.R. Clark, and J.E. Clark, eds. Wetland functions and values: the state of our understanding. American Water Resources Association, Minneapolis. 674 p. Conant, R., and J.T. Collins. 1991. A field guide to reptiles and amphibians (eastern and central North America). Third edition. Houghton Miflin, Boston. 450 p. 141 WETLANDS Conlin, M. 1991. Illinois River fisheries and wildlife resources. Pages 28-36 in Proceedings of the 1991 Governor’s Conference on the Management of the Illinois River System. 166 p. Cowardin, L.M., V. Carter, and E.T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31, U.S. Government Printing Office. 131 p. Crum, H. A. 1988. A focus on peatlands and peat mosses. Ann Arbor, Michigan. Dahl, T.E. 1990. Wetlands losses in the United States 1780’s to 1980’s. U.S. Fish and Wildlife Service, Washington, D.C. 21 p. Dahl, T.E., and C.E. Johnson. 1991. Status and trends of wetlands in the conterminous United States, mid-1970’s to mid-1980’s. U.S. Fish and Wildlife Service, Washington, D.C. 28 p. Demissie, M., and A. Khan. 1993. Influence of wetlands on streamflow in Illinois. Report to Illinois Department of Conservation, Springfield. 47 p. Donnan, W.W., and J. Sutton. 1960. Engineering for drainage. Pages 113-118 in Alfred Stefferud, ed. Power to produce. The Yearbook of Agriculture, 86th Congress, Second Session. House Document No. 269. Dreher, D.W., R.D. Mariner, and C. Hunt. 1988. Stream and wetland protection: a natural resource management priority in northeastern Illinois. Northeastern Illinois Planning Commission. Chicago. 117 p. Ebinger, J.E. 1978. Vascular flora of hillside seeps in east-central Illinois. Transactions of the Illinois State Academy of Science 71:109-114. Environmental Defense Fund and World Wildlife Fund. 1992. How wet is a wetland?: the impacts of the proposed revisions to the federal wetlands delineation manual. 175 p. Erwin, K.L. 1991. An evaluation of wetland mitigation in the South Florida Water Management District. South Florida Water Management District, West Palm Beach. Vol. I. Evans, D.L. 1982. Status reports on twelve raptors. U.S. Fish and Wildlife Service Spec. Sci. Rep., Wildl. 238. Washington, D.C. 68 p. Farber, S., and R. Costanza. 1987. The economic value of wetland systems. Journal of Environmental Management 24:41-51. Feierabend, J.S., and J.M. Zelazny. 1987. Status report on our nation’s wetlands. National Wildlife Federation, Washington, D.C. 46 p. 142 Frayer, W.E., T.J. Monahan, D.C. Bowden, and F.A. Graybill. 1983. Status and trends of wetlands and deepwater habitats in the conterminous United States, 1950’s to 1970’s. Department of Forestry and Wood Science, Colorado State University, Fort Collins. 32 p. Fritzell, E.K. 1988. Mammals and wetlands. Pages 213-226 in D.D. Hook, W.H. McKee, Jr., H.K. Smith, J. Gregory, V.G. Burrell, Jr., M.R. DeVoe, R,E. Sojka, S. Gilbert, R. Banks, L.H. Stolzy, C. Brooks, T.D. Matthews, and T.H. Shear, eds. The Ecology and management of wetlands. Vol. 1: Ecology of wetlands. Croom Helm, London and Sydney. 592 p. Gardner, J.E., J.D. Garner, and J.E. Hofmann. 1990. Combined progress reports: 1989 and 1990 investigations of Myotis sodalis (Indiana bat) distribution, habitat use, and status in Illinois. Progress report, Endangered Species Coordinator, Region 3, U.S. Fish and Wildlife Service and Bureau of Location and Environment, Illinois Department of Transportation. iv+19 p. Gardner, J.E., J.D. Garner, and J.E. Hofmann. 1991. Summer roost selection and roosting behavior of Myotis sodalis (Indiana bat) in Illinois. Unpub- lished report, Endangered Species Coordinator, Region 3, U.S. Fish and Wildlife Service and Indiana/Gray Bat Recovery Team, U.S. Fish and Wildlife Service. 56 p. Gardner, J.E., J.E. Hofmann, J.D. Garner, J.K. Krejca, and S.E. Robinson. 1992. Distribution and status of Myotis austroriparius (southeastern bat) in Illinois. Unpublished report, Illinois Natural History Survey and Illinois Department of Conser- vation. 38 p. Gould, J.B., and L. Gould. 1991. Illinois Exotic Weed Act. Illinois Conservation Law. Chapter 5, Sec. 932. Definition, Sec. 933. Exotic weeds, Sec. 934. Exotic weed control. Illinois Conservation Law, Binghamton, New York. Graber, J.W., R.R. Graber, and E.L. Kirk. 1978. Illinois birds: Ciconiiformes. Illinois Natural History Survey Biological Notes 109. 80 p. Gupta, T.R., and J.H. Foster, 1975. Economic criteria for freshwater wetland policy in Massachusetts. American Journal of Agricultural Economics 57:40-4S. Harty, F. M. 1986. Exotics and their ecological ramifications. Natural Areas Journal 6:20-26. Havera, S.P. 1985. Waterfowl of Illinois: status and management. Final Federal Aid Performance Report, 1980-1985. Cooperative Waterfowl Research W-88-R. 785 p. . 1992. Waterfowl of Illinois: status and management. Final report to Illinois Department of Conservation. W-110-R. 1,065 p. Havera, S.P., and F.C. Bellrose. 1985. The Illinois River: a lesson to be learned. Wetlands 4:29-41. Havera, S.P., L.R. Boens, M.M. Georgi, and R.T. Shealy. 1992. Human disturbance of waterfowl on Keokuk Pool, Mississippi River. Wildlife Society Bulletin 20:290-298. Hedges, S.B. 1986. An electrophoretic analysis of holarctic hylid frog evolution. Systematic Zoology 35:1-21. Heidorn, R. 1991. Vegetation management guideline: exotic buckthorns, common buckthorn (Rhamnus cathartica L.), glossy buckthorn (R. frangula L.) and Dahurian buckthorn (R. davurica Pall.). Natural Areas Journal 11:216-217. Heidorn, R., W. Glass, D. Ludwig, and M. Cole. 1991. Northeastern Illinois wetlands survey for endan- gered and threatened birds: a summary of field data: 1980-1989. Illinois Department of Conserva- tion, Natural Heritage General Tech. Rep. #1. 157 p. Heidorn, R., and B. Anderson, B. 1991. Vegetation management guideline: purple loosestrife (Lythrum salicaria). Natural Areas Journal 11:172-173. Heilner, V.C. 1943. A book on duck shooting. Alfred A. Knopf, New York. 540 p. Heinrich, J.W., and S.R. Craven. 1992. The economic impact of Canada geese at the Horicon Marsh, Wisconsin. Wildlife Society Bulletin 20:364—371. Henry, R.D., and A.R. Scott. 1980. Some aspects of the alien component of the spontaneous Illinois vascular flora. Transactions of the Illinois State Academy of Science 73:35—40. Herkert, J.R., ed. 1991. Endangered and threatened species of Illinois: status and distribution. Volume 1 — Plants. Illinois Endangered Species Protection Board, Springfield. 158 p. , ed. 1992. Endangered and threatened species of Illinois: status and distribution. Vol. 2 — Animals. Illinois Endangered Species Protection Board, Springfield. 142 p. Hester, N.C., and J. E. Lamar. 1969. Peat and humus in Illinois. Illinois State Geological Survey, Industrial Minerals Notes 37. Urbana, Illinois. Hoffmeister, D.F. 1989. Mammals of Illinois. Univer- sity of Illinois Press, Urbana. 348 p. Hofmann, J.E. 1991. Status and distribution of wetland mammals in Illinois. Illinois Natural History Survey Bulletin 34:409-415. WETLANDS Hofmann, J.E., J.E. Gardner, and M.J. Morris. 1990. Distribution, abundance, and habitat of the marsh rice rat (Oryzomys palustris) in southern Illinois. Transactions of the Illinois State Academy of Science 83:162-180. Howell, J. A., and W. H. Blackwell, Jr. 1977. The history of Rhamnus frangula (glossy buckthorn) in the Ohio flora. Castanea 42:111-115. Hubbell, M.E., S.E. Baum, and T.D. Shaffer. 1993. Illinois wetlands conservation strategy. Final report—Phase |. Report by Illinois Department of Conservation and Illinois Natural History Survey to U.S. Environmental Protection Agency, Chicago. 178 p. Humphrey, S.R., A.R. Richter, and J.B. Cope. 1977. Summer habitat and ecology of the endangered Indiana bat, Myotis sodalis. Journal of Mammal- ogy 58:334-346. Illinois Department of Agriculture. 1992. Annual progress report. Illinois Department of Agriculture, Division of Natural Resources 73 p. Illinois Department of Conservation. 1993. Outdoor economics. Outdoor Highlights 21:6-7. Illinois Fish and Wildlife Information System. Illinois Department of Conservation, Springfield. Illinois Natural Heritage Database. Illinois Department of Conservation, Division of Natural Heritage, Springfield. Illinois Tax Commission. 1941. Drainage district organization and finance, 1879-1937. State of Illinois, Springfield. 213 p. Iverson, L.R. 1992. Illinois Plant Information Network (ILPIN). Illinois Natural History Survey, Champaign. Johnson, C.W. 1985. Bogs of the northeast. University Press of*New England, Hanover and London. Jones, G.N., and G. D. Fuller. 1955. Vascular Plants of Illinois. University of Illinois Press, Urbana, and the Illinois State Museum, Scientific Papers Series Vol. XI. Springfield. 135 p. Kennedy, D.D., and E. Lewis. 1977. In search of the Canada goose. Great Lakes Living Press, Matteson, Illinois. 149 p. Kentula, M.E., J.C. Sifneos, J.W. Good, M. Rylko, and K. Kunz. 1992. Trends and patterns in Section 404 permitting requiring compensatory mitigation in Oregon and Washington, USA. Environmental Management 16:109-119. Kjolhaug, M.S., A. Woolf, and W.D. Klimstra. 1987. Current status and distribution of the swamp rabbit in Illinois. Transactions of the Illinois State Academy of Science 80:299-—307. 143 WETLANDS Korschgen, C.E., L.S. George, and W.L. Green. 1985. Disturbance of diving ducks by boaters on a migrational staging area. Wildlife Society Bulletin 13:290-296. Korte, P.A., and L.H. Fredrickson. 1977. Swamp rabbit distribution in Missouri. Transactions of the Missouri Academy of Science 10 and 11:72-77. Ladd, D.M. and R.M. Mohlenbrock. 1983. New distribution data for Illinois vascular plants. Erigenia 3:2—21. La Val, R.K., R.C. Clawson, M.L. La Val, and W. Caire. 1977. Foraging behavior and nocturnal activity of Missouri bats, with emphasis on the endangered species Myotis grisescens and Myotis sodalis. Journal of Mammalogy 58:592-599. Lee, M.T., and J.B. Stahl. 1976. Sediment conditions in backwater lakes along the Illinois River. Illinois State Water Survey Contract Rep. 176. 73 p. Linzey, D.W., and R.L. Packard. 1977. Ochrotomys nuttalli. Mammalian Species 75:1-6. Livermore, B. 1992. Amphibian alarm: just where have all the frogs gone? Smithsonian 23:113—120. Lockart, J. 1980. Wetlands: wild places worth saving. Outdoor Highlights. January 21. Millsap, B.A. 1986. Status of wintering bald eagles in the conterminous 48 states. Wildlife Society Bulletin 14:433-440. Minton, S.A., Jr. 1972. Amphibians and reptiles of Indiana. Indiana Academy of Science Monograph No. 3. 346 p. Mitsch, W.J., and J.G. Gosselink. 1986. Wetlands. Van Nostrand Reinhold, New York. 539 p. Mohlenbrock, R. H. 1985. New distribution data for Illinois vascular plants II. Erigenia 5: 53-64. . 1986. Guide to the vascular flora of Illinois. Revised and enlarged edition. Southern Illinois University Press, Carbondale. 507 p. Mohlenbrock, R. H., and D. Ladd. 1978. Distribution of Illinois vascular plants. Southern Illinois University Press, Carbondale. 282 p. Moll, E.O., and M.A. Morris. 1991. Status of the river cooter, Pseudemys concinna, in Illinois. Transac- tions of the Illinois State Academy of Science 84:77-83. Morris, M.A. 1974. An Illinois record for a triploid species of the Ambystoma jeffersonianum com- plex. Journal of Herpetology 8:255-256. . 1991. Breeding biology and larval life history of four species of Ambystoma (Amphibia: Caudata) in east-central Illinois. Illinois Natural History Survey Bulletin 34:402 (abstract). 144 Morris, M.A., R.S. Funk, and P.W. Smith. 1983. An annotated bibliography of the Illinois herpetologi- cal literature 1960-1980, and an updated checklist of species of the state. Illinois Natural History Survey Bulletin 33:123-137. Mumford, R.E., and J.O. Whitaker, Jr. 1982. Mammals of Indiana. Indiana University Press, Bloomington. 537 p. Ott, J. 1990. Studying wetland protection programs in Wisconsin. EPA, Wisconsin Department of Natural Resources, Madison. Page, L.M., and B.M. Burr. 1991. A field guide to freshwater fishes (North America north of Mexico). Houghton Miflin, Boston. 432 p. Parmalee, P.W. 1958. Remains of rate and extinct birds from Illinois Indian sites. Auk 75:169-176. Pechuman, L.L., D.W. Webb, and H.J. Teskey. 1983. The Diptera, or true flies, of Illinois: I. Tabanidae. Illinois Natural History Survey Bulletin 33:1—122. Pechmann, J.H.K., D.E. Scott, R.D. Semlitsch, J.P.Caldwell, L.J. Vitt, and J.W. Gibbons. 1991. Declining amphibian populations: the problem of separating human impacts from natural fluctua- tions. Science 253:892-895. Peters, D.S., D.W. Arenholz, and T.R. Rice. 1978. Harvest and value of wetland associated fish and shellfish. Pages 606-617 in P-E. Greeson, J.R. Clark, and J.E. Clark, eds. Wetland functions and values: the state of our understanding. American Water Resources Association, Minneapolis. 674 p. Peterson, J.W. 1991. Erosion and sediment — today’s challenge. Proceedings of the Forty-seventh annual meeting of the Upper Mississippi River Conservation Committee. p. 4-11. Phillips, C.A. 1991. Geographical distribution: Ambystoma jeffersonianum (Jefferson sala- mander). Herpetological Review 22:133. Phillips, K. 1990. Where have all the frogs and toads gone? Bioscience 40:422-424. . 1991. Frogs in trouble. International Wildlife 20:4—11. Pierce, G.J. 1989. Wetland soils. Pages 65-74 in S.K. Majumdar, R.P. Brooks, F.J. Brenner, and R.W. Tiner, Jr., eds. Wetlands ecology and conservation: emphasis in Pennsylvania. The Pennsylvania Academy of Scienc, Easton. Post, S.L. 1991. Appendix one: native Illinois species and related bibiography. Illinois Natural History Survey Bulletin 34(4):463-475. Postupalsky, S. 1971. Toxic chemicals and declining bald eagles and cormorants in Ontario. Canadian Wildlife Service, Pesticide Section, Manuscript Reports No. 20. 65 p. Reed, P.B., Jr. 1988. National list of plant species that occur in wetlands: 1988 Illinois. U.S. Fish and Wildlife Service. National Wetland Inventory Office, St. Petersburg, Florida. Biological Report NERC-88-18.13. Ridgway, R. 1889. The ornithology of Illinois. Part I. Descriptive catalogue. State of Illinois, Spring- field. 520 p. . 1895. The ornithology of Illinois. Part II. Descriptive catalogue. State of Illinois, Spring- field. 282 p. Ross, H.H. 1947. The mosquitoes of Illinois (Diptera, Culicidae). Illinois Natural History Survey Bulletin 24: 1-96. Ross, H.H., and W.R. Horsfall. 1965. A synopsis of the mosquitoes of Illinois (Diptera, Culicidae). Illinois Natural History Survey Biological Notes 52. Runge, E.C.A., L.E. Taylor, and S.G. Carmer. 1969. Soil type acreages for Illinois. University of Illinois, Agricultural Experiment Station and Soil Conservation Service, U.S. Department of Agri- culture Bulletin 735. Samson, LE., and S.B. Bhagwat. 1985. Illinois mineral industry in 1981—1983 and review of preliminary mineral production data for 1984. Illinois State Geological Survey, Illinois Mineral Notes 93. Sanderson, G.C., F.C. Bellrose, and G.V. Burger. 1979. Wetland habitat in Illinois. Proceedings of the Governor’s Wildlife Habitat Confercne. p. 101-118. Scherff, E.E. 1912. Range extensions of Rhamnus frangula and Sporobolus asperifolius. Rhodora 14:227-228. Schwegman, J.E. 1985. Purple plague. Outdoor Highlights 13:10-11. Sheviak, C.J. 1974. An introduction to the ecology of the Illinois Orchidaceae. Illinois State Museum Scientific Papers XIV. Springfield. 89 p. . 1981. Endangered and threatened plants. Pages 70-179 + appendices V and VI in Natural Land Institute. Endangered and threatened vertebrate animals and vascular plants of Illinois. Illinois Department of Conservation, Springfield. Sifneos, J.C., E.S. Cake Jr., and M.E. Kentula. 1992a. Effects of Section 404 permitting on freshwater wetlands in Louisiana, Alabama, and Mississippi. Wetlands 12:28-36. Sifneos, J.C., M.E. Kentula, and P. Price. 1992b. Impacts of Section 404 permits requiring compen- satory mitigation of freshwater wetlands in Texas and Arkansas. Texas Journal of Science 44:475—485. WETLANDS Smith, M., and S. Dreiband. 1991. Fish and Wildlife Service studies cormorant to help curb recreational and aquacultural losses. North Central Region News, U.S. Fish and Wildlife Service. March 8. 2p. Smith, P.W. 1961. The amphibians and reptiles of Illinois. Illinois Natural History Survey Bulletin 28:1-298. . 1971. Illinois streams: a classification based on their fishes and an analysis of factors respon- sible for disappearance of native species. Illinois Natural History Survey Biological Notes No. 76. 14 p. . 1979. The fishes of Illinois. University of Illinois Press, Urbana. 314 p. Soil Conservation Service. 1993. Hydric soil acreage in 80 Illinois counties. Personal communication with John Doll (11 January 1993) of the United States Department of Agriculture, Soil Conservation Service, database on the soils of Illinois, in cooperation with Illinois Agricultural Experiment Station. Champaign, Illinois. Soper, E.K., and C.C. Osbon. 1922. The occurrence and uses of peat in the United States. U.S. Geological Survey Bulletin 728. Stefferud, A., ed. 1958. Land. The Yearbook of Agriculture. 85th Congress, second session. House Document No. 280. 605 p. Steinhart, P. 1990. No net loss. Audubon. July, p. 18, 20-21. Suloway, L., M. Hubbell, and R. Erickson. 1992. Analysis of the wetland resource of Illinois. Vol. I. Overview and general results. Report to Illinois Department of Energy and Natural Resources. 35 p. Swink, F., and G. Wilhelm. 1979. Plants of the Chicago region. The Morton Arboretum, Lisle, Illinois. Taft, J., and M.K. Solecki. 1990. Vascular flora of the wetland and prairie communities at Gavin Bog and Prairie Nature Preserve, Lake County, Illinois. Rhodora 92:142-165. Thomas, G. 1990. Honk if you love southern Illinois. Outdoor Highlights 18:3-7. Thompson, D.Q. 1991. History of purple loosestrife (Lythrum salicaria L.) biological control efforts. Natural Areas Journal 11(3):148-150. Thompson, D.Q., R.L. Stuckey, and E.B. Thompson. 1987. Spread, impact, and control of purple loosestrife (Lythrum salicaria) in North American wetlands. U.S. Fish and Wildlife Service, Fish and Wildlife Res. No. 2. U.S. Department of the Interior, Washington, D.C. 55 p. 145 ADS ee eee Thompson, J. 1988. From carp to corn, an historical geography of land drainage in the lower Illinois valley, 1890-1930. Report to Water Resources Center, Univ. of Illinois at Champaign-Urbana. Sept. 1988. 454 p. Tiner, R.W., Jr. 1984. Wetlands of the United States: current status and recent trends. U.S. Fish and Wildlife Service, National Wetlands Inventory, Newton Corner, Massachusetts. 59 p. U.S. Department of Agriculture, Soil Survey Staff. 1975. Soil taxonomy. A basic system of soil classification for making and interpreting soil surveys. U.S. Department of Agriculture, Soil Conservation Service, Washington, D.C. 754 p. U.S. Department of Agriculture—Soil Conservation Service. 1985. Hydric soils of the United States. U.S. Department of Agriculture-SCS Nat. Bull. No. 430-5-9, Washington, D.C. U.S. Department of Agriculture, Soil Conservation Service. 1987. Hydric soils of the United States. In cooperation with the National Technical Committee for Hydric Soils. U.S. Department of Agriculture, Soil Conservation Service, Washing- ton, D.C. U.S. Department of Commerce. 1978. Census of agriculture. U.S. Fish and Wildlife Service. 1986. Use of lead shot for hunting migratory birds in the United States. Final Supplemental Environmental Impact Statement. Department of the Interior, Washing- ton, D.C. 256 p. U.S. Fish and Wildlife Service. 1990. Endangered and threatened wildlife and plants; review of plant taxa for listing as endangered or threatened species; notice of review. 50 CFR Part 17. p. 6184-6229. U.S. Fish and Wildlife Service. 1991. Endangered and threatened wildlife and plants; animal candidate review for listing as endangered or threatened species. 21 November 50 CFR Part 17, Federal Register 56(225):58804—58836. Wake, D.B. 1991. Declining amphibian populations. Science 253:860. Warner, R.E., S.P. Havera, and L.M. David. 1985. Effects of autumn tillage systems on corn and soybean harvest residues in Illinois. Journal of Wildlife Management 49:185—190. Warren, M.L., Jr. and B.M. Burr. 1989. Distribution, abundance, and status of the cypress minnow, Hybognathus hayi, an endangered Illinois species. Natural Areas Journal 9:163—168. 146 Wetlands Research, Inc. 1992. Research opportunities in a rehabilitated ecosystem. Wetlands Research, Inc., Chicago. 7 p. Whitaker, J.O., Jr., and B. Arbell. 1986. The swamp rabbit, Sylvilagus aquaticus, in Indiana. Proceed- ings of the Indiana Academy of Science 95:563— 570. White, J. 1978. Illinois natural areas inventory techni- cal report. Vol. 1: Survey methods and results. Illinois Natural Areas Inventory, Urbana. 426 p. Wilen, B.O. 1990. The U.S. Fish and Wildlife Service’s National Wetlands Inventory. Pages 9— 20 in S.J. Kiraly, F.A. Cross, and J.D. Buffington, eds. Federal coastal wetland mapping programs: a report by the National Ocean Pollution Policy Board’s Habitat Loss and Modification Working Group. U.S. Fish and Wildlife Service Biological Report 90(18). Wilen, B.O., and W.E. Frayer. 1990. Status and trends of U.S. wetlands and deepwater habitats. Forest Ecology and Management 33/34:181—192. Wilhelm, G., and L. Wetstein. 1992a. Productivity and vegetation: potential plant communities. The Des Plaines River Wetlands Demonstration Project. Wetlands Research Inc., Chicago. . 1992b. Vegetational monitoring of a wetland restoration in northern Illinois. Proceedings of the Society of Wetland Scientists Conference, New Orleans, Louisiana. Willman, H.B. 1971. Summary of the geology of the Chicago area. Illinois State Geological Survey Circular 460. Willman, H.B., and J.C. Frye. 1970. Pleistocene stratigraphy of Illinois. Illinois State Geological Survey Bulletin 94. Winterringer, G.S., and R.A. Evers. 1960. New records for Illinois vascular plants. Illinois State Museum, Scientific Papers Series, Vol. XI, Springfield. 135 p. Wolfe, J.L. 1982. Oryzomys palustris. Mammalian Species 176:1-S. Wright, J.O. 1907. Swamp and overflowed lands in the United States: ownership and reclamation. U.S. Department of Agriculture, Office of Experiment Stations, Circular 76, Washington, D.C. Wyman, R.L. 1990. What’s happening to the amphib- ians? Conservation Biology 4:350—352. Appendix 1. Common plant names used in this report with the corresponding scientific names. The suffix spp. (species plural) indicates that two or more species in the genus are included in the discussion. Common name Arrowhead Bald cypress Black ash Bluejoint grass Bulrushes Bur-reed Buttonbush Cattails Cordgrass Cottonwood Dogwood Glossy buckthorn Grass parnassus Green ash Hackberry Jewel weed Joe-pye-weeds Manna grass Marsh marigold Oaks Pickerelweed Purple loosestrife Red-osier dogwood Rushes Sedges Silver maple Skunk cabbage Spatterdock Swamp rose Sycamore Tamarack Thismia Tussock sedge Virginia willow Water lily Water tupelo Willow Scientific name Sagittaria latifolia Taxodium distichum Fraxinus nigra Calamagrostis canadensis Scirpus spp. Sparganium androcladum Cephalanthus occidentalis Typha spp. Spartina pectinata Populus deltoides Cornus spp. Rhamnus frangula Parnassia glauca Fraxinus pennsylvanica Celtis occidentalis Impatiens capensis Eupatorium spp. Glyceria septentrionalis Caltha palustris Quercus spp. Pontederia cordata Lythrum salicaria Cornus stolonifera Juncus spp. Carex spp. Acer saccharinum Symplocarpus foetidus Nuphar luteum Rosa palustris Platanus occidentalis Larix laricina Thismia americana Carex stricta Itea virginica Nymphaea tuberosa Nyssa aquatica Salix spp. WETLANDS Appendix 2. Approximate amount of hydric soil representing presettlement wetlands in each county of Illinois. The recent survey of hydric soils is currently incomplete. The complete estimate of hydric soil is from Havera (1985). Percentage of Number of hydric Estimated hydric acres/ acres from recent number of county from County name soil survey hydric acres __ estimated data Adams 99,494 164,700 31 Alexander 112,276 47,700 48 Bond 91,187 17,200 7 Boone 127,748 37,400 21 Brown 23,012 35,600 19 Bureau 134,020 104,400 20 Calhoun 36,285 16,600 11 Carroll = —_ -=------ 19,200 7 Cass 62,550 59,900 26 Champaign 313,275 283,100 47 Christian 159,690 124,300 29 Clark 125,181 62,700 20 Clay 150,336 52,400 19 Clinton 165,965 99,100 32 Coles 117,795 122,300 41 Cook/Dupage 215,171 93,800, 49,700 47, 38 Crawford 104,229 38,900 15 Cumberland _ --------- 37,500 18 DeKalb 138,500 16,500 4 DeWitt —— --------- 79,300 33 Douglas 148,792 144,700 56 Edgar =r ==- 177,500 47 Edwards 202,763 66,900 48 Effingham 118,195 39,800 14 Fayette 162,025 92,300 22 Ford 187,507 140,400 47 Franklin _—_—--------- 80,200 31 Fulton 102,500 124,800 24 Gallatin 82,125 87,200 44 Greene 83,200 87,900 26 Grundy 139,240 85,800 35 Hamilton 96,383 96,300 37 Hancock 99,600 62,500 13 Hardin =——— =w== === 7,300 8 Henderson ~)_—-------- 38,600 17 Henry 100,290 77,500 15 Iroquois 402,078 268,400 39 Jackson =======-- 105,600 31 Jasper 158,510 71,500 23 Jefferson = ~~ --------- 42,400 12 Jersey 30,706 48,400 21 Jo Daviess 23,235 26,900 7 Johnson 33,639 32,200 16 Kane 106,976 92,300 31 Kankakee 162,692 106,900 27 Kendall 58,340 57,500 30 Knox 41,345 33,000 8 Lake 67,828 78,000 45 La Salle 213,247 213,700 31 147 a WTA DS ne 8 ee ea ee eee Appendix 2 (continued) Number of hydric Estimated acres from recent number of County name soil survey hydric acres Lawrence 86,268 70,800 Lee 148,954 111,100 Livingston 476,915 276,800 Logan 150,660 47,300 Macon 157,400 132,700 Macoupin 187,734 78,700 Madison 180,135 45,900 Marion —_—=-===---- 55,400 Marshall == —_—--------- 36,000 Mason 116,585 80,800 Massac 2 ====-=-== 52,700 McDonough 82,740 34,100 McHenry 103,743 110,800 McLean 170,205 190,800 Menard 43,272 36,000 Mercer 45,815 37,100 Monroe 63,255 56,300 Montgomery 225,735 93,000 Morgan 67,995 29,300 Moultrie = =------- 88,700 Ogle 64,260 39,100 Peoria 45,165 52,900 Perry 2 wrero== 173,500 Piatt 132,465 123,900 Pike 45,900 127,200 Pope ss =rw====- 15,200 Pulaski 112,276 59,800 Putnam 40,370 15,300 Randolph 59,168 65,400 Richland 257,140 30,800 Rock Island —--------- 33,400 St.Clair 0 =----=--- 77,600 Saline 74,140 109,800 Sangamon 157,265 33,500 Schuylar = ====----- 69,800 Scott 41,299 36,700 Shelby 106,723 37,400 Stark 22,300 24,700 Stephenson —_—-------- 20,400 Tazewell 90,460 90,300 Union wren 56,500 Vermilion =—_--------- 245,300 Wabash 53,612 48,600 Warren 53,745 65,400 Washington ~~ -------- 101,200 Wayne 185,930 159,400 White 111,660 105,300 Whiteside 132,615 65,900 Will 184,792 210,300 Williamson _ -------- 42,000 Winnebago 136,033 42,900 Woodford — -------- 68,100 Total 9,412,659 8,261,600 148 Percentage of hydric acres/ county from estimated data 31 25 43 12 40 15 12 16 15 24 36 10 31 26 19 23.1 Appendix 3. Illinois bird species that can use wetlands. Common name Common loon Pied-billed grebe® Horned grebe Red-necked grebe Eared grebe American white pelican Double-crested eprmorant® American bijiers Least bittern Great blue heron Great egret” Snowy egret Little blue heron Cattle egret Green-backed heron Black-crowned night-heron® Yellow-crowned night-heron® Tundra swan Greater white-fronted goose Snow goose Canada goose Wood duck Green-winged teal American black duck Mallard Northern pintail Blue-winged teal Northern shoveler Gadwall American wigeon Canvasback Redhead Ring-necked duck Greater scaup Lesser scaup Common goldeneye Bufflehead Hooded merganser Common merganser Red-breasted merganser Ruddy duck Black vulture Turkey, vulture Osprey Mississippi kite Bald eagle™ Northern harrier Sharp-shinned hawk? Cooper's hawk? Northern goshawk Red-shouldered hawk Broad-winged hawk Swainson’s hawk Red-tailed hawk Rough-legged hawk American kestrel Merlin Peregrine falcon Ring-necked pheasant Wild turkey Northern bebwhite Yellow rail a,b Scientific name Gavia immer Podilymbus podiceps Podiceps auritus Podiceps grisegena Podiceps nigricollis Pelecanus erythrorhynchos Phalacrocorax auritus Botaurus lentiginosus Ixobrychus exilis Ardea herodias Casmerodius albus Egretta thula Egretta caerulea Bubulcus ibis Butorides striatus Nycticorax nycticorax Nycticorax violaceus Cygnus columbianus Anser albifrons Chen caerulescens Branta canadensis Aix sponsa Anas crecca Anas rubripes Anas platyrhynchos Anas acuta Anas discors Anas clypeata Anas strepera Anas americana Aythya valisineria Aythya americana Aythya collaris Aythya marila Aythya affinis Bucephala clangula Bucephala albeola Lophodytes cucullatus Mergus merganser Mergus serrator Oxyura jamaicensis Coragyps atratus Cathartes aura Pandion haliaetus Ictinia mississippiensis Haliaeetus leucocephalus Circus cyaneus Accipiter striatus Accipiter cooperii Accipiter gentilis Buteo lineatus Buteo platypterus Buteo swainsoni Buteo jamaicensis Buteo lagopus Falco sparverius Falco columbarius Falco peregrinus Phasianus colchicus Meleagris gallopavo Colinus virginianus Coturnicops noveboracensis Appendix 3 (continued) Common name Black rail King rail® Virginia rail Sora Purple gallinule Common moorhen® American coo Sandhill crane Black-bellied plover Lesser golden- plover Semipalmated saab Piping plover™ Killdeer Greater yellowlegs Lesser yellowlegs Solitary sandpiper Willet Spotted sandpiper Upland sandpiper Sanderling Semipalmated sandpiper Western sandpiper Least sandpiper White-rumped sandpiper Baird’s sandpiper Pectoral sandpiper Dunlin Stilt sandpiper Short-billed dowitcher Long-billed dowitcher Common snipe American woodcock Wilson’s phalarope? Red-necked phalarope Franklin’s gull Bonaparte’s gull Ring-billed gull Herring gull Thayer’s gull Iceland gull Caspian tern Common tem Forster's ten” Least tern” Black tern Rock dove Mourning dove Black-billed cuckoo Yellow-billed cuckoo Common barn-owl Eastern screech-owl Great horned owl Snowy owl Burrowing owl Barred owl Long-eared owl Short-eared owl Northern saw-whet owl Common nighthawk Chuck-will’s-widow Whip-poor-will Chimney swift Scientific name Laterallus jamaicensis Rallus elegans Rallus limicola Porzana carolina Porphyrula martinica Gallinula chloropus Fulica americana Grus canadensis Pluvialis squatarola Pluvialis dominica Charadrius semipalmatus Charadrius melodus Charadrius vociferus Tringa melanoleuca Tringa flavipes Tringa solitaria Catoptrophorus semipalmatus Actitis macularia Bartramia longicauda Calidris alba Calidris pusilla Calidris mauri Calidris minutilla Calidris fuscicollis Calidris bairdii Calidris melanotos Calidris alpina Calidris himantopus Limnodromus griseus Limnodromus scolopaceus Gallinago gallinago Scolopax minor Phalaropus tricolor Phalaropus lobatus Larus pipixcan Larus philadelphia Larus delawarensis Larus argentatus Larus thayeri Larus glaucoides Sterna caspia Sterna hirundo Sterna forsteri Sterna antillarum Chlidonias niger Columba livia Zenaida macroura Coccyzus erythropthalmus Coccyzus americanus Tyto alba Otus asio Bubo virginianus Nyctea scandiaca Athene cunicularia Strix varia Asio otus Asio flammeus Aegolius acadicus Chordeiles minor Caprimulgus carolinensis Caprimulgus vociferus Chaetura pelagica Appendix 3 (continued) Common name Ruby-throated hummingbird Belted kingfisher Red-headed woodpecker Red-bellied woodpecker Yellow-bellied sapsucker Downy woodpecker Hairy woodpecker Northern flicker Pileated woodpecker Olive-sided flycatcher Eastern wood-pewee Yellow-bellied flycatcher Acadian flycatcher Alder flycatcher Willow flycatcher Least flycatcher Eastern phoebe Great crested flycatcher Eastern kingbird Horned lark Purple martin Tree swallow Northern rough-winged swallow Bank swallow Cliff swallow Barn swallow Blue jay American crow Fish crow Common raven Black-capped chickadee Carolina chickadee Tufted titmouse Red-breasted nuthatch White-breasted nuthatch Brown creeper” Carolina wren Bewick’s wren House wren Winter wren Sedge wren Marsh wren Golden-crowned kinglet Ruby-crowned kinglet Blue-gray gnatcatcher Eastern bluebird Veery® Gray-cheeked thrush Swainson’s thrush Hermit thrush Wood thrush American robin Gray catbird Northern mockingbird Brown thrasher Cedar waxwing Northern shrike Loggerhead shrike® European starling White-eyed vireo Bell's vireo Solitary vireo WETLANDS ___ Scientific name Archilochus colubris Ceryle alcyon Melanerpes erythrocephalus Melanerpes carolinus Sphyrapicus varius Picoides pubescens Picoides villosus Colaptes auratus Dryocopus pileatus Contopus borealis Contopus virens Empidonax flaviventris Empidonax virescens Empidonax alnorum Empidonax traillii Empidonax minimus Sayornis phoebe Myiarchus crinitus Tyrannus tyrannus Eremophila alpestris Progne subis Tachycineta bicolor Stelgidopteryx serripennis Riparia riparia Hirundo pyrrhonota Hirundo rustica Cyanocitta cristata Corvus brachyrhynchos Corvus ossifragus Corvus corax Parus atricapillus Parus carolinensis Parus bicolor Sitta canadensis Sitta carolinensis Certhia americana Thryothorus ludovicianus Thryomanes bewickii Troglodytes aedon Troglodytes troglodytes Cistothorus platensis Cistothorus palustris Regulus satrapa Regulus calendula Polioptila caerulea Sialia sialis Catharus fuscescens Catharus minimus Catharus ustulatus Catharus guttatus Hylocichla mustelina Turdus migratorius Dumetella carolinensis Mimus polyglottos Toxostoma rufum Bombycilla cedrorum Lanius excubitor Lanius ludovicianus Sturnus vulgaris Vireo griseus Vireo bellii Vireo solitarius 149 a WW ETIDANDS: ne SS SSS Appendix 3 (continued) Common name Yellow-throated vireo Warbling vireo Philadelphia vireo Red-eyed vireo Blue-winged warbler Golden-winged warbler Tennessee warbler Orange-crowned warbler Nashville warbler Northern parula Yellow warbler Chestnut-sided warbler Magnolia warbler Cape may warbler Black-throated blue warbler Yellow-rumped warbler Black-throated green warb Blackburnian warbler Yellow-throated warbler Pine warbler Prairie warbler Palm warbler Bay-breasted warbler Blackpoll warbler Cerulean warbler Black-and-white warbler American redstart Prothonotary warbler Worm-eating warbler Swainson’s warbler Ovenbird Northern waterthrush Louisiana waterthrush Kentucky warbler Connecticut warbler Mourning warbler Common yellowthroat Hooded warbler Wilson’s warbler Canada warbler Yellow-breasted chat Summer tanager Scarlet tanager Northern cardinal Rose-breasted grosbeak Blue grosbeak Indigo bunting Green-tailed towhee Rufous-sided towhee American tree sparrow Chipping sparrow Clay-colored sparrow Field sparrow Vesper sparrow Lark sparrow Savannah sparrow Grasshopper sparrow Henslow’s sparrow Le conte’s sparrow Sharp-tailed sparrow Fox sparrow Song sparrow 150 Scientific name Vireo flavifrons Vireo gilvus Vireo philadelphicus Vireo olivaceus Vermivora pinus Vermivora chrysoptera Vermivora peregrina Vermivora celata Vermivora ruficapilla Parula americana Dendroica petechia Dendroica pensylvanica Dendroica magnolia Dendroica tigrina Dendroica caerulescens Dendroica coronata Dendroica virens Dendroica fusca Dendroica dominica Dendroica pinus Dendroica discolor Dendroica palmarum Dendroica castanea Dendroica striata Dendroica cerulea Mniotilta varia Setophaga ruticilla Protonotaria citrea Helmitheros vermivorus Limnothlypis swainsonit Seiurus aurocapillus Seiurus noveboracensis Seiurus motacilla Oporornis formosus Oporornis agilis Oporornis philadelphia Geothlypis trichas Wilsonia citrina Wilsonia pusilla Wilsonia canadensis Icteria virens Piranga rubra Piranga olivacea Cardinalis cardinalis Pheucticus ludovicianus Guiraca caerulea Passerina cyanea Pipilo chlorurus Pipilo erythrophthalmus Spizella arborea Spizella passerina Spizella pallida Spizella pusilla Pooecetes gramineus Chondestes grammacus Passerculus sandwichensis Ammodramus savannarum Ammodramus henslowii Ammodramus leconteii Ammodramus caudacutus Passerella iliaca Melospiza melodia Appendix 3 (continued) Common name Lincoln's sparrow Swamp sparrow White-throated sparrow White-crowned sparrow Dark-eyed junco Lapland longspur Smith’s longspur Snow bunting Bobolink Red-winged blackbird Eastern meadowlark Western meadowlark Yellow-headed blackbird Rusty blackbird Brewer’s blackbird Common grackle Brown-headed cowbird Orchard oriole Northern oriole Purple finch House finch Red crossbill White-winged crossbill Common redpoll Pine siskin American goldfinch Evening grosbeak House sparrow Eurasian tree sparrow @ Federally endangered. State endangered. © State threatened. Scientific name Melospiza lincolnii Melospiza georgiana Zonotrichia albicollis Zonotrichia leucophrys Junco hyemalis Calcarius lapponicus Calcarius pictus Plectrophenax nivalis Dolichonyx oryzivorus Agelaius phoeniceus Sturnella magna Sturnella neglecta Xanthocephalus xanthocephalus Euphagus carolinus Euphagus cyanocephalus Quiscalus quiscula Molothrus ater Icterus spurius Icterus galbula Carpodacus purpureus Carpodacus mexicanus Loxia curvirostra Loxia leucoptera Carduelis flammea Carduelis pinus Carduelis tristis Coccothraustes vespertinus Passer domesticus Passer montanus Appendix 4. Mammal species in Illinois that use wetlands. Common name Virginia opossum Masked shrew Southeastern shrew Northern short-tailed shrew Southern short-tailed shrew Eastern mole Little brown bat Indiana bat# Southeastern bat Gray bat Northern long-eared bat Silver-haired bat Eastern pipistrelle Big brown bat Red bat Hoary bat Evening bat Rafinesque’s big-eared bat Swamp rabbit Franklin’s ground squirrel Gray squirrel Fox squirrel Southern flying squirrel Beaver Marsh rice rat© Western harvest mouse White-footed mouse Golden mouse© Meadow vole Prairie vole Woodland vole Muskrat Southern bog lemming House mouse Meadow jumping mouse Zapus hudsonius Coyote Canis latrans Red fox Vulpes vulpes Gray fox Urocyon cinereoargenteus Raccoon Procyon lotor Least weasel Mustela nivalis Long-tailed weasel Mustela frenata Mink Mustela vison Striped skunk Mephitis mephitis River otter Lutra canadensis Bobcat Lynx rufus White-tailed deer Odocoileus virginianus 4 Federally endangered. b State endangered. ¢ State threatened. Scientific name Didelphis virginiana Sorex cinereus Sorex longirostris Blarina brevicauda Blarina carolinensis Scalopus aquaticus Myotis lucifugus Myotis sodalis Myotis austroriparius Myotis grisescens Myotis septentrionalis Lasionycteris noctivagans Pipistrellus subflavus Eptesicus fuscus Lasiurus borealis Lasiurus cinereus Nycticeius humeralis Plecotus rafinesquii Sylvilagus aquaticus Spermophilus franklinii Sciurus carolinensis Sciurus niger Glaucomys volans Castor canadensis Oryzomys palustris Reithrodontomys megalotis Peromyscus leucopus Ochrotomys nuttalli Microtus pennsylvanicus Microtus ochrogaster Microtus pinetorum Ondatra zibethicus Synaptomys cooperi Mus musculus WETLANDS ____ Appendix 5. Amphibian species in Illinois that use wetlands. Common name Jefferson salamander Blue-spotted salamander Spotted salamander Marbled salamander Silvery salamander Mole salamander Smallmouth salamander Tiger salamander Eastern newt Dusky salamander Southern two-lined salamander Longtail salamander Cave salamander Four-toed salamander Mudpuppy Lesser siren Eastern spadefoot toad American toad Fowler’s toad Northern cricket frog Bird-voiced treefrog Cope’s gray treefrog Green treefrog Gray treefrog Spring peeper Upland chorus frog Illinois chorus frog? Wester chorus frog Crawfish frog Plains leopard frog Bullfrog Green frog Pickerel frog Northern leopard frog Wood frog Southern leopard frog Scientific name Ambystoma jeffersonianum Ambystoma laterale Ambystoma maculatum Ambystoma opacum Ambystoma platineum Ambystoma talpoideum Ambystoma texanum Ambystoma tigrinum Notophthalamus viridescens Desmognathus fuscus Eurycea cirrigera Eurycea longicauda Eurycea lucifuga Hemidactylium scutatum Necturus maculosus Siren intermedia Scaphiopus holbrookii Bufo americanus Bufo woodhousii Acris crepitans Hyla avivoca Hyla chrysoscelis Hyla cinerea Hyla versicolor Pseudacris crucifer Pseudacris feriarum Pseudacris streckeri Pseudacris triseriata Rana areolata Rana blairi Rana catesbeiana Rana clamitans Rana palustris Rana pipiens Rana sylvatica Rana utricularia Eastern narrowmouth toad Gastrophryne carolinensis 4 State endangered. b State threatened. 151 _____ WETLANDS Appendix 6. Reptile species in Illinois that use wetlands. Common name Snapping turtle Alligator snapping turtle Illinois mud turtle Eastern mud turtle Common musk turtle Painted turtle Common slider River cooter4 Spotted turtle@ Blanding’s turtle Common map turtle False map turtle Eastern box turtle Smooth softshell turtle Spiny softshell turtle Eastern fence lizard Five-lined skink Broadhead skink Ground skink Worm snake Kirtland’s snake Racer Ringneck snake Great plains rat snake Rat snake Mud snake Eastern hognose snake Common kingsnake Green water snakeD Plainbelly water snake Broad-banded water snake® Diamondback water snake Northern water snake Rough green snake Smooth green snake Graham’s crayfish snake Brown snake Redbelly snake Western ribbon snake Plains garter snake Eastern ribbon snake Common garter snake Smooth earth snake Copperhead Cottonmouth Timber rattlesnake Massasauga 4 State endangered. b State threatened. 152 Scientific name Chelydra serpentina Macroclemys temminckii Kinosternon flavescens Kinosternon subrubrum Sternotherus odoratus Chrysemys picta Trachemys scripta Pseudemys concinna Clemmys guttata Emydoidea blandingii Graptemys geographica Graptemys pseudogeographica Terrepene carolina Apalone mutica Apalone spinifera Sceloporus undulatus Eumeces fasciatus Eumeces laticeps Scincella lateralis Carphophis amoenus Clonophis kirtlandii Coluber constrictor Diadophis punctatus Elaphe guttata Elaphe obsoleta Farancia abacura Heterodon platyrhinos Lampropeltis getula Nerodia cyclopion Nerodia erythrogaster Nerodia fasciata Nerodia rhombifer Nerodia sipedon Opheodrys aestivus Opheodrys vernalis Regina grahamii Storeria dekayi Storeria occipitomaculata Thamnophis proximus Thamnophis radix Thamnophis sauritus Thamnophis sirtalis Virginia valeriae Agkistrodon contortrix Agkistrodon piscivorus Crotalus horridus Sistrurus catenatus Appendix 7. Threatened and endangered fish that use wetlands. Common name Least brook lamprey Alligator gar Cypress minnow Pugnose shiner Ironcolor shiner Blackchin shiner Blacknose shiner Bluehead shiner Banded killifish Spotted sunfish Bantam sunfish Iowa darter Scientific name Lampetra aegyptera Atractosteus spatula Hybognathus hayi Notropis anogenus Notropis chalybaeus Notropis heterodon Notropis heterolepis Pteronotropis hubbsi Fundulus diaphanus Lepomis punctatus Lepomis symmetricus Etheostoma exile LAKES AND IMPOUNDMENTS SUMMARY Lakes and impoundments have reflected the effects of intensive agriculture, urbanization, industrialization, and species introductions, all of which have accelerated since World War II. Significant changes in fish species compositions have occurred in Lake Michigan due to deliberate and accidental species introductions (exotics now constitute 17% of all fish species), shoreline habitat and drainage area deterioration, and over- exploitation of some fish stocks. Recreational fishing in the Illinois part of Lake Michigan is now dominated by a native yellow perch fishery and a subsidized, introduced salmonid fishery. Because impoundment construction accelerated after many land-use changes had begun, data indicating trends in impoundments are limited. However, soil loss due to row-crop and livestock farming, in addition to the removal of stream riparian vegetation, has resulted in high sedimentation rates that are capable of filling some impoundments in less than 100 years. Most impoundments are also artificially eutrophicated due to agricultural fertilizers and urban waste. There is no evidence for multispecies overexploitation in impound- ments by recreational or commercial fishermen, when overexploitation is defined as a decrease in total yield when fishing effort increases. The definition of overexploitation of individual fish species stocks depends on the size structure of fish desired, but there is no evidence of recruitment failures or extinctions due to excessive exploitation. Major increases in expenditure on the stocking of fish have occurred, but the benefits of stocking to specific angling groups compared to the overall benefits of improving habitat and other management alternatives have not been explored. INTRODUCTION True lakes are restricted to the extreme northeast of Illinois because of the effects of glaciation. Lake Michigan is the conspicuous example of this set because of its size and historical importance and is treated in a separate section. The only other natural lakes are the few remaining floodplain lakes that are more appropriately considered as part of a river- floodplain system. Human-made lakes—which range from the three U.S. Army Corps of Engineers reser- voirs (Rend Lake, Lake Shelbyville, and Lake Carlyle) down to small farm ponds—have come to dominate the existing lacustrine environment due largely to an acceleration in construction in the 1960s (Figure 1). Data useful for environmental trend analysis from impoundments and small lakes were found to be - sparse. This, in combination with the limited time since construction, results in only a few time-series from impoundments of sufficient quality to assist in critical trend assessments. However, the effects of changes in 15000 10000 5000 Lakes Constructed, in Hectares of Surface Area 1941 1880 1900 YEAR Figure 1. Amount of lake surface area created by impounding streams and rivers during 5-year time periods since 1880. Data reflect the construction of a set of 124 lakes throughout Illinois. No significant surface area has been added since 1980. The peak in 1935 reflects the construction of Lake Springfield and the increase in water level on the Fox Chain O’ Lakes, which are natural lakes that were affected by the construction of McHenry Dam on the Fox River. The peak during 1960-1975 represents the major period of lake construction, which included the three U.S. Army Corps of Engineers reservoirs (Carlyle, Rend, and Shelbyville). 153 _______ LAKES AND IMPOUNDMENTS land use, such as the greatly increased use of agricul- tural fertilizers in the past 30 years, has been patently obvious on the majority of lakes in agricultural watersheds. Such lakes exhibit all the signs of eutrophi- cation, such as excessive algal and macrophyte growth and anoxic water below the thermocline in the summer. Lakes and impoundments are the repository of much waste (e.g., soil, toxic chemicals, nutrients) carried in by rivers and therefore have the potential to act as environmental barometers. In addition, they are resources in that they attract significant recreational and commercial fishing, long-term records of which might demonstrate their sustainability and reflect environmental change in the future. IMPOUNDMENTS/SMALL LAKES Abiotic Factors Sedimentation. The rate of sedimentation is probably the strongest indicator of external environmental change affecting impoundments. Although sediment transport by rivers is natural and the lifetime of all lakes is finite, the rate of accumulation of sediments in the majority of our lakes has been phenomenal (Figure 2). This is mainly due to row-crop and livestock-based agriculture practices, which have accelerated since the 1950s, and the concurrent decrease in natural riparian vegetation bordering affluent streams. The issue is not just the effect of rapid additions of new sediment, which can negatively affect macrophyte growth, benthos production, and spawning/nursery areas for some fish, but the lifetime of the lake. For example, Lake Decatur has lost a third of its volume in 60 years, and Lake Pittsfield has lost nearly a quarter of its volume in only 24 years (Figure 2). Correcting this process by dredging is very expensive, a cost which, in turn, can be minor compared with the disposal of pesticide-contaminated spoil. The only viable long- term solution is to change land-use practices, particu- larly with regard to row-crop agriculture, livestock farming, and stream corridors. Water Quality. Data series on impoundments are currently too limited to observe trends that are ex- pected from agricultural and urban inputs, whose major effects are clear from the longer time series available from rivers. Most impoundments were constructed after the acceleration of intensified row-crop and livestock-based agriculture and associated fertilizer and pesticide additions occurred. 154 Hydrology. Hydrology is often an ignored factor in lakes because it is assumed that their water level fluctuations are limited and unimportant. In fact, a predictable spring rise and steady retreat in summer can be extremely important for the spawning and/or nursery grounds for many fish species, just as it is in rivers. Water levels during 15 years are compared in Figure 3 for three U.S. Army Corps of Engineers reservoirs: Rend Lake, Lake Carlyle, and Lake Shelbyville. Rend Lake has a fixed spillway, so water level is a function of rainfall, runoff, and the capacity of the system, and produces a fairly predictable flood pulse in the spring and few surprises at other times of the year (Figure 3). Conversely, Lakes Carlyle and Shelbyville are manipulated in an attempt to prevent the natural flooding process downstream. This results in drawdowns when large inflows are expected, resulting in spawning and nursery areas for some species being dry during critical periods in the spring. 100 95 90 85 80 75 % of Original Volume Remaining 70 65 1920 1930 1940 1950 1960 1970 1980 1990 YEAR Symbol Lake Name County Original Capacity (acre-feet) —6— Lake Bracken Knox 2881 = Ee Lake Pittsfield Pike 3580 —o- Arctic Lake Macoupin 176 ~—€ - Lake Carlinville Macoupin 2350 ss+- - Lake Decatur Macon 27900 —A - Lake Springfield Sangamon 59900 -?e Lake Bloomington McLean 6650 —s- Frankfurt Res. Franklin 1700 Figure 2. Storage capacity loss for eight Illinois lakes. Lakes with four or more sedimentation studies were selected for this analysis from data in Singh and Durgunoglu (1990). These eight lakes currently have an average storage capacity loss of 0.52%/year. This loss is primarily attributable to siltation as a result of soil erosion. Future land use practices will determine to a large extent whether this pattern will continue. Most impoundments are unregulated but do not necessarily have good spawning and rearing habitats. This is a subject for research when current fishery data programs produce sufficiently long time-series. Recreational Fishing Sport fishing license sales generally increased from 1941 through 1971, followed by a stable period in which a slight decline was noted (Figure 4). However, these data do not account for angling by senior citizens (except for 1960-1975) and minors, who do not need licenses. Since 1977, recreational fishing effort in the U.S. Army Corps of Engineers reservoirs (and in Lake Michigan) has tended to decline, while in the remain- ing bodies of water it has, at least until 1986, steadily increased (Figure 5) without a parallel increase in fishable waters. However, total harvest has been strongly positively related to fishing effort in all impoundments sampled in recent years (Figure 6), and higher harvest rates were not obtained at the cost of inferior fish species or smaller fish. Overexploitation of the total fish resource, which would have been indi- cated with a flat or negative relationship between harvest and effort, is evidently not a concern. However, the ability of lakes to produce more fish may be constrained by environmental factors. Time series of recreational harvest and effort data on individual lakes are too limited to draw definite con- clusions, but scattered data from reservoirs (Figure 7) 620 — Spc nena TVA 72 Cs FRETS 76 77 78 79 80 81 82 83 84 85 Figure 3. Daily water levels (feet above sea level) for 1971-1985 for three U.S. Army Corps of Engineers reservoirs. Levels of Lake Shelbyville (top) and Carlyle Lake (middle) are regulated, whereas Rend Lake (bottom) has an unregulated spillway. Data are from the U.S. Army Corps of Engineers, St. Louis. LAKES AND IMPOUNDMENTS do not suggest any trends during 25 years in a general index of sport fish biomass. However, even though total weight of catch may have been maintained, angler satisfaction may have been negatively affected by reduced mean size of fish caught in some impoundments. Commercial Fishing Nonriverine commercial fishing has been confined to a few lakes, among which two U.S. Army Corps of Engineers reservoirs, Carlyle and Rend Lakes (Figure 8), attract the most effort. These fisheries are heavily controlled to minimize conflicts with recreational fisheries; therefore, harvest is mainly limited by how much time the fishermen can operate each year. When fishing effort is accounted for, the overall trend does not suggest that the resource, consisting mostly of common carp and various buffalo species, is being depleted by the fishery (Arnold W. Fritz, Illinois Department of Conservation, personal communica- tion). It should be added that these species are gener- ally more tolerant of poor water quality and high rates of sedimentation and are not sought by most recre- ational fishermen. Fish Stocking A variety of species have been stocked in lakes (see also Lake Michigan below), and quantities stocked 1,000 ” ® @ 800 88 ra) = ~ 600 oO 2 ES 2 5 400 © Qa DD > @ 200 > 45% canopy), areas of mixed vegetation (< 45% canopy), grassy areas (noncultivated), agricultural areas, urban or developed areas, disturbed or barren areas, reser- voirs, and other water areas. For the present report, forested areas and areas of mixed vegetation, grassy areas (noncultivated) and agricultural areas, and reservoirs and other water areas were combined to form a total of five coverage types (Table 1). There are large differences among the 10 drainage basins in the percentages of forest/mixed and agricul- ture/grass buffer strips (Table 1). In the heavily forested southern portion of the state, 81% of the buffer strip area has forest/mixed coverage and only 11% agriculture/grass coverage. In contrast, in the agricul- turally dominated Rock River basin, only 55% of the buffer strip coverage is forest/mixed, and 43% is agriculture/grass. Channelization Channelized streams are extremely common in Illinois, largely as a result of agricultural demands throughout the state (Figure 3). Channelization has been widely practiced throughout the United States and elsewhere (e.g., see Hortle and Lake 1982), largely for improving drainage from agricultural lands and for flood control (i.e., enhancing runoff after storms). However, channelization can have substantial adverse effects on physical and, consequently, biotic parameters in streams and the adjacent riparian zone. Among the major effects of channelization are a reduction in habitat diversity for invertebrates and fish (from a variety of causes) and increases in bank erosion and sediment transport. Generally, channelization results in reductions in the abundance and diversity of benthic invertebrates and fish (Hortle and Lake 1982, Henegar and Harmon 1973), and these negative effects may persist for very long periods after the initial channelization of a stream (Arner et al. 1976). Ownership of Streamside Land Public ownership of streamside land is extremely important for the promotion of environmental educa- tion and outdoor recreation in Illinois. Public owner- ship of these areas allows for the creation of preserva- tion and conservation areas as well as the generation of revenues for other state interests. Currently the state owns 15% of the land bordering streams that drain 10 square miles or more. There are large differences among basins in the amount of publicly owned land along streams. For example, in the basin of the Fox and FLOWING WATERS Table 1. The percentage of land in each land-use category within 82 feet (25 m) on either side of streams in each of the 10 major drainage basins in Illinois. Land-use category Basin Forest/mixed Agriculture/grass Rock 54.7 43.0 Fox 66.0 24.7 Kankakee 43.9 53.2 Spoon 70.0 26.9 Sangamon 598 35.4 La Moine 75.9 21.0 Kaskaskia 76.2 21.4 Embarras Osa 29.0 Little Wabash 76.4 19.6 Big Muddy 81.2 iL? Urban Water Barren 0.76 0.78 0.17 3.50 2.18 1.04 0.22 1.08 0.47 0.03 1.81 0.05 0.05 S)5)| 0.02 0.16 1.16 0.56 0.36 3.26 0.30 0.08 0.65 0.10 0.02 1.60 0.08 0.06 3.05 0.39 Des Plaines rivers, nearly 40% of the land bordering streams draining 10 square miles or more is owned by the state, whereas in the Little Wabash River basin only 5.9% is considered public land (Figure 4). Recreational Canoeing Another important aspect of publicly owned streamside areas is the accessibility for specific uses such as recreational canoeing. Again, there are considerable differences among basins in the amount of canoeable streams (Figure 5). Percentages of stream length that are canoeable vary from 20.9% in the basin of the Fox and Des Plaines rivers to 0.1% in the Little Wabash River basin. These percentages are calculated by summing the lengths from the uppermost public entry points on streams within the basin downstream to either the stream’s end or the point at which it exits the basin. Because traditional canoe access points on public or quasi-public land could not be included in this data set, it is likely that Figure 5 underestimates the amount of canoeable streams in each basin. CURRENT STATUS OF BIOLOGICAL COMMUNITIES Several governmental agencies in Illinois have given high priority to activities aimed at the protection of aquatic habitats and their biota. Two recent studies have sought to identify the state’s most biologically significant streams. The Biological Stream Characterization (BSC) is a stream-quality index developed by the Illinois Depart- ment of Conservation and the Illinois Environmental Protection Agency to categorize streams (Hite and Bertrand 1989). The BSC is based largely on fish and aquatic macroinvertebrate diversity and relies primarily on the Index of Biotic Integrity (Karr et al. 1986). This index assesses the biological condition of streams by using a range of fish community attributes that fall into three broad categories: species composition, trophic composition, and fish abundance and condition. In the BSC, stream segments are categorized from “A” to “E.” “A” streams are considered to be in excellent condition, comparable to the pristine conditions that existed in Illinois prior to human disturbance. “B” streams are in good condition and typically support important game fishes, but overall species diversity is below expectations. “C” streams are in fair condition, typically with reduced diversity and a game fish population consisting primarily of bullheads, sunfishes, and carp. “D” streams are in poor condition and have notably reduced diversity, with the community domi- nated by environmentally tolerant species. The “E” category comprises very poor streams that support only a few individuals of the most environmentally tolerant species of fishes and macroinvertebrates. As of December 1988, 614 stream segments had been evaluated, representing approximately 29% of the stream miles in Illinois (Hite and Bertrand 1989). Only 4% of the stream miles studied were classified as type A (Figures 6 and 7), Unfortunately, 66% of the stream _____. FLOWING WATERS 50.0% 40.0% 30.0% 20.0% 10.0% % of Basin channelized 0.0% Ros Fox & Des Plain Little Wabas! Embarras & Vermili Big Muddy & Shawn Kankakee, Vermilion & Mackin: Figure 3. Percentage of each basin’s total stream length that has been altered through channelization. Data were collected from 1981 to 1990 and cover only those streams that drain an area of 10 sq. mi. of the basin or more and; therefore, the data most likely underestimate the basin-wide percentage of channelized streams. Channelization data were collected from several sources: (1) an Illinois Depart- ment of Conservation (IDOC) Division of Fisheries report titled “Channelized Streams and Ditches of Illinois,” (2) county highway maps from the Illinois Department of Transportation (IDOT), (3) Agricultural Stabilization and Conservation Service (ASCS) aerial photogrtaphy slides, and (4) the most recent U.S. Geological Survey (USGS) 7.5-minute topographic maps. The IDOC report listed the lengths of channelized stream segments per county but did not give the location. Channelized stream segments were located using county highway maps, ASCS aerial slides, and USGS 7.5-minute topographic maps. Ground truth surveys in the Sangamon River basin were then carried out to verify the location accuracy of several of these stream segments. 176 40.0% 30.0% 20.0% 10.0% 0.0% % of total stream length with public land Spoot Sangamon La Moine Kaskaskia Little Wabash Basin Fox & Des Plaine: Embarras & Vermilio Big Muddy & Shawnee Kankakee, Vermilion & Mackina Figure 4. Percentage of stream length that is bordered by public land in each basin. To assess the extent of accessible public land holdings along Illinois’ streams, the most recent county plat books and government agency publications about land holdings were used to identify owners, who were then contacted for more specific information about these sites. The Sangamon Basin was the first completed by the Illinois Streams Information System (ISIS). It was the testing ground for surveys used in the other basins. Included in the Sangamon Basin are areas such as privately owned golf courses, scouting camps, country clubs, utilities, sewage disposal areas, landfills, cemeteries, schools, churches, and hospitals. After the Sangamon, the data type was more specifically defined as publicly owned and accessible to the general public for recreation. Basins other than the Sangamon are limited to these types of areas and do not include pseudo-public areas or areas unavailable for recreation use. This graph represents only those streams that drain 10 sq. mi. or more of area within the boundaries of Illinois. The data here can be considered accurate as of the date associ- ated with the source; however, public ownership of land changes slowly. In addition, certain areas of the state have been previously surveyed on a more local level (by county agencies, etc.) as to public land holdings and are, therefore, probably more complete. 20.0% 10.0% 0.0% % of total stream length canoeable Fox & Des Plaines Embarras & Vermi Little Wabas! Big Muddy & Shawnee Kankakee, Vermilion & Mackinaw Figure 5. Percentage of each basin’s total length of rivers and streams that can be canoed after being accessed at a publicly owned streamside area. This graph includes only those streams that drain 10 sq. mi. or more of area within Illinois. For the purpose of this figure, it is assumed that a stream can be canoed from the point of entry until the point at which it either ends or exists the basin. Although the Mississippi, the Illinois, and the Wabash rivers can be canoed, their lengths are not included as canoeable in this graph. The canoeable lengths of these rivers within Illinois from the uppermost public access site to the point where they exit the state are 578.8, 272.4, and 190.4 miles, respectively. From this graph it appears that a very small percentage of Illinois’ potentially canoeable streams are being utilized. However, this graph underestimates the availability of canoeable areas in Illinois because it does not include quasi-public and private access points that are frequently used by the public. However, this figure and Figure 4 demonstrate that in some Illinois basins such as the LaMoine and Little Wabash the availability of public recreation sites and canoeable stream areas is severly limited and public land purchases may be necessary to increase accessibility. FLOWING WATERS miles were rated C or lower and have been severely degraded (Figures 6 and 7). In a second study, described in a report titled “Biologi- cally Significant Illinois Streams: An Evaluation of the Streams of Illinois Based on Aquatic Biodiversity” (Page et al. 1992), the list of streams identified in the BSC as biologically significant was expanded by considering additional data on biodiversity. The expanded list identifies streams and stream segments that support populations of federal or state threatened, endangered, or “watch list” species of fishes, mussels, crayfishes, and vascular plants, as well as those with the highest fish (BSC “A” streams) and mussel diversity. Streams were assumed to support threatened, endangered, or watch list species if the species have been observed there since 1980. One hundred eight streams supporting threatened, endangered, or watch list species or supporting a high diversity of mussels were identified. These streams, in addition to the 24 streams identified as “A” streams in the BSC classifi- cation, bring to 132 the number of biologically significant streams and stream segments currently recognized in Illinois (Figure 8). TRENDS IN WATERSHED CHANGES AND RESOURCE USE Land Use in Watersheds The structure and function of flowing water ecosystems are intimately related to the geology, terrestrial vegetation, and many additional aspects of the sur- rounding landscape (Hynes 1975, Vannote et al. 1980, Naiman and DeCamps 1990). In particular, it is becoming increasingly recognized that the nature and extent of riparian vegetation adjacent to running waters can profoundly influence numerous physical, chemical, and biotic characteristics of streams and rivers, such as channel morphology and streambank stability, inputs of solar radiation (which influences instream primary production and thermal regimes), inputs of dissolved nutrients, inputs of sediment from the adjacent land- scape, and inputs of terrestrial organic matter (Gregory et al. 1991). All of these effects on physical and chemical factors can strongly influence the biotic characteristics of flowing waters. For these reasons, land-use practices in watersheds, especially in riparian zones, can significantly affect the integrity of stream ecosystems. Data that address changes in land-use practices within drainage basin, watersheds, and riparian zones are not 177 FLOWING WATERS B - Highly valued A - Unique a a at see -2 Sak s a yy) w 3 Me ate es ae eee ore ieee L Be ai i‘ naa \} a \ ii Poe Me: a ays Pee ae 7 se wa J Ene ey D/E - Limited or restricted C - Moderate Figure 6. Biological characterization of Illinois streams. 178 30% > o » a wv OS@&sS gg moo oy 43° Figure 7. Percentage of Illinois stream miles surveyed that were rated by the Biological Stream Characteriza- tion in each classification. currently available for the entire state. Extensive data are available for Champaign County, which we summarize below. Five major drainage basins occur in Champaign County, with three of these (Kaskaskia, Embarras, Little Vermilion) originating within the county (Figure 9). For all basins combined, the amount of land in urban use increased markedly (37.4%) between 1958 and 1988, while the amount of land in agriculture and forest declined by 0.84% and 8.6%, respectively (Figure 10). These changes in land use were not uniform across basins. For example, forested land decreased by 80% in the Little Vermilion basin, with most of that land being converted to agricultural use (Osborne et al. 1991). The Embarras and Kaskaskia basins experienced 40% and 70% reductions, respec- tively, in forested land. However, in those systems, the land was converted largely to urban use (Osborne et al. 1991), These basin-wide changes in land use do not accurately reflect changes that occurred in the riparian zone adjacent to streams. For example, the amount of urban land within 100 feet of a stream increased by 67.5% between 1958 and 1988 (Figure 10). Again, these changes in land use in the riparian area were not distributed uniformly among basins. For example, the amount of urban land within 100 feet of streams increased in the Embarras and Kaskaskia basins by 450% and 550%, respectively (Osborne et al. 1991). These basins and the Little Vermilion and Sangamon basins experienced appreciable losses (10—-100%) of forested land adjacent to streams; in the Sangamon and Little Vermilion this land was largely converted to FLOWING WATERS _____ Pant os Rs SN s! “(ZF she wS \ ’ mH Figure 8. Biologically significant Illinois streams. LANDUSE CATEGORIES (_] urban [) Agrounure (33) Fores: Ge wee HR worn GE care, Figure 9. Champaign County land use. 179 ACRES FLOWING WATERS 10000 1000 10 1000000 100000 10000 1000 100 —— URBAN AG FOREST WATER BARREN Figure 10. The amount of land in each of the five land- use categories in Champaign County: (A) within 100 feet of stream channels and (B) in the entire county. Land use was interpreted from 7.5-minute (1:24,000) (1988) or 15-minute (1:64,000) (1958) USGS topo- graphic maps using GIS (ARC/INFO). Land-use/cover patterns within 100 feet of stream channels were determined using the ARC/INFO “buffer” facility. agricultural use. These data indicate that a dispropor- tionate amount of urbanization and, to a lesser extent, conversion of forested land to agricultural land has occurred in the riparian zone relative to other areas in the drainage basins. These trends in land use in the riparian zone are of particular concern because of the known value of forested riparian vegetation to mid- western streams (Karr and Schlosser 1978, Schlosser and Karr 1981, Osborne and Wiley 1988, Wiley et al. 1990) and because urbanization in the immediate vicinity of stream channels often has adverse effects on stream integrity (e.g., Karr and Dudley 1981, Osborne and Wiley 1988). 180 Dam Construction Dam construction is one of the major physical alter- ations of Illinois’ flowing waters. Almost every major river in Illinois has an impoundment along its course. There are nearly 1200 dams of all sizes in Illinois (Figure 11). The completion date was available for 110 dams (excluding those built on the Mississippi and Ohio rivers) with greater than 1000 acre-feet of normal water storage; these are discussed below. There were two peaks in dam construction in this century (Figures 12 and 13). The 1930s saw large-scale changes in the nature of large rivers in Illinois. The Illinois and Mississippi rivers were converted from free-flowing rivers into a series of navigable pools by the construction of locks and dams (O’Brien et al. 1992). The second peak in dam construction occurred during the 1960s and 1970s. Recreation and, to a lesser extent, water supply were the reasons stated for the construction of these impoundments. The largest reservoirs in Illinois were completed during this time, including Carlyle (Kaskaskia River, 1967), Shelbyville (Kaskaskia River, 1970), and Rend (Big Muddy River, 1971). Flood control was the primary purpose recorded for these impoundments. High levels of dam construc- tion continued during the 1980s. The average size of these impoundments, however, was much smaller than those built during the previous two decades (Figure 12). Coal mining and utility companies own 12 of the 18 dams constructed during the 1980s. Physical, chemical, and biological alterations result from impounding a free-flowing stream. These changes occur both upstream and downstream of the dam and include alteration of temperature, flow regime, sedi- ment transport, and chemical concentrations. Dams also present a barrier to migration and a loss of flowing-water habitat. Damming results in the creation of an artificial lake directly upstream from the dam and an altered lotic ecosystem in the receiving stream (Ward 1984). When multiple dams are placed along a waterway, such as on the Mississippi, Ohio, Illinois, and Rock rivers, the current and depth along the length of the river are altered, and the entire nature of the river is changed. A natural flowing stream, consisting of alternating riffles and pools, contains numerous distinctive habitats and, typically, high species diver- sity of fish and other aquatic organisms. In contrast, a reservoir on an impounded stream has comparatively low habitat and species diversity. Ward and Stanford (1979) and Baxter (1977) review some of the effects of dams and impoundments. Additionally, Ward and Stanford (1983) describe a conceptual framework (the e < 1000 Acre Feet @ 1000-10000 Acre Feet e > 10000 Acre Feet 230 << 40000 30000 20 . Sree E 20000 = eae = es o = —s— Acre-feot < 10 10000 o i?) 00 10 20 30 40 50 60 70 80 Decade Figure 12. The number of dams constructed in Illinois in each decade between 1900 and 1990 and their mean normal storage. Only dams having greater than 1000 acre-feet of normal storage are included. This figure excludes 19 lock and dams constructed on the Missis- sippi and Ohio rivers. Source: Illinois Department of Transportation, Division of Water Resources. FLOWING WATERS Serial Discontinuity Concept) in which to view changes caused by an impoundment to a lotic ecosys- tem along a longitudinal profile. A solitary factor can rarely be demonstrated to cause a change in the biota of a stream, but several authors have discussed the effects of dams on the biota of Illinois streams. Smith (1971) cited dams as one of the factors responsible for changes in fish populations in Illinois. He attributed the decimation of four native fish species to mainstream impoundments on the North Fork Vermillion and Embarras rivers, although he found the effects of dams on the fishes of the Missis- sippi, Illinois, Kaskaskia, and Rock rivers more difficult to assess. Suloway et al. (1981) discussed the effects of impoundment on the mussel fauna of the Kaskaskia River. Burks (1953) reflected on changes in the mayfly fauna near Rock Island in relation to the change of the Mississippi and Rock rivers from large, rapidly flowing rivers to sluggish water bodies. Navigation/Barge Traffic Barge traffic on the Illinois and Mississippi rivers has increased dramatically since 1950 although increases have leveled off in the past 10 years (Figure 14). Barge traffic and the activities associated with maintenance of the shipping channel may have a variety of deleterious effects on river ecosystems, few of which have been extensively examined. Propellers of tow boats are extremely large (up to 9 feet in diameter), and the outwash from these propellers can churn up the bottom of the river, moving and resuspending sediments into the water column and thereby altering the river bed. The impact of this type of disturbance on benthic fish and invertebrates is not clearly understood. The wake created by barges is also a potential source of environ- mental damage, increasing bank erosion and accelerat- ing undercutting and exposure of the roots of trees in riparian forests along the banks of the rivers. Mainte- nance of the channel by dredging also potentially affects river ecosystems both through direct distur- bance of benthic habitats when material is removed and also because the dredged material is deposited along the banks of the river, artificially building them up and separating riparian areas from the river. Sport Fishing Pressure Sport fishing in Illinois generates tremendous revenues from both residents and nonresidents alike. Statewide fishing pressure has increased dramatically since 1965, and at the current rate of increase Illinois can expect a 40% rise in total annual angling days (one angling day 181 FLOWING WATERS Figure 13. Illinois dams of 10,000 acre feet or greater storage by year of construction. Barge Traffic: Illinois and Mississippi Rivers 100 Mississippi (pool 14) a 80 Mississippi (pool 26) 2 c Illinois (mouth to Lockport’ 2 60 a E o = 40} = 3 F 20 0 1950 1960 1970 1980 1990 Year Figure 14. Volume of commercial traffic reported from sections of the upper Mississippi and Illinois rivers at 10-year intervals between 1950 and 1988. Pool 26 is above Alton and below the confluence of the Illinois and Mississippi rivers. Traffic reported from here is thus a composite of Illinois River traffic and traffic from the rest of the upper Mississippi River. Pool 14 is above Moline. Illinois River data is for the river below Lockport. 182 is one fisherman fishing all or any part of one day) by the year 2010 (Figure 15). Although approximately 70% of angling days are spent on public and private lakes, Illinois streams receive considerable fishing pressure annually (Baur 1991). Overall, Illinois’ streams have received approximately a 20% increase in total angling days from 1977 to 1989 (Figure 16). The Mississippi River has demonstrated the largest increase, receiving 52% more angling days in 1989 than it did in 1977. Other streams have received similar increases in fishing pressure (Figure 16). Fishing pressure in Illinois’ small streams has fluctuated the most over the past decade and has actually experienced a 41% decrease in total angling days annually received since 1977 (Figure 16). However, the decline between 1986 and 1989 is probably a function of annual variation in water levels. Although overall fishing pressure in our streams has varied dramatically, the hierarchy of the most popu- larly sought sport fish has remained relatively constant © Angling days Angling Days (millions) 1960 1965 1970 1975 19680 1985 1990 1995 2000 2005 2010 Year Figure 15. Number of days spent sport fishing in Illinois. More then 1.4 million anglers sport fished in Illinois during 1989, with only 4.2% of the anglers being from outside the state. Anglers averaged 28.3 fishing trips in Illinois during the year, with resident anglers averaging 29.0 trips and nonresident anglers averaging 11.9 trips. In 1990 anglers spent over 41 million days fishing in Illinois’ lakes, ponds, and streams. At the current rate of increase, by the year 2010 the number of angling days is likely to increase by over 40% to approximately 57 million angling days per year (one angling day is one fisherman fishing all or any part of a day). The above projection was created from a regression analysis (r= .802) of angling day estimates from 1965 to 1990. Source: Office of Resource Management, Division of Fisheries, Illinois Department of Conservation, Springfield. (Figure 17). Catfish, black bass, walleye and sauger, and crappie have remained the top four groups of sport fish sought after since 1977 (Figure 17). Of the four groups however, black bass have continually risen in popularity while preference for the others has remained fairly stable. Fish Kills Attributable to Pollution Streams are occasionally subject to disturbances so severe that they result in unusually high mortality of animals or plants in an area. Normally such distur- bances result from natural causes (e.g., severe floods or droughts; see Hynes 1970), but they can also be induced by human activities. Fortunately, a common result (i.e., high mortality of fish) of such human perturbations to streams usually is quite obvious, and consequently, the events are often reported to the Illinois Environmental Protection Agency (IEPA) and/ or the Illinois Department of Conservation (IDOC). FLOWING WATERS —+— Mississippi River Illinois River Other large rivers Small Streams Percent change in total angling days Figure 16. Percent change in sport fishing on Illinois rivers and streams, 1977-1989. Illinois’ flowing waters have experienced dramatic increases in fishing pressure over the past 30 years. Between 1977 and 1989 the average number of angling days (one angling day = any one fisherman fishing all or any part of one day) spent by both resident and nonresident fishermen was over 11 million per year. The group of “other large rivers” receives approximately 4 million angling days per year, which is just under a million more angling days annually than received by the Mississippi River, averaging nearly 3.2 million. Small streams in Illinois and the Illinois River average approximately 2 million angling days annually. The zero percent line indicates the total number of angling days received by each group in 1977, and the following yearly estimates are increases or decreases in angling days relative to the 1977 estimate. Overall, there has been nearly a 21% increase in total angling days since 1977. The Mississippi River has received the largest increase with over 52% more angling days in 1989 than in 1977. Both the Illinois River and other large rivers have shown increases of nearly 30%. In contrast, small streams have experienced a 41% decrease in angling days annually. This drop, however, is most likely associated with a significant decrease in fishable surface area of small streams due to the 1988 drought, and therefore a large increase should be expected during the next survey period. Source: Office of Resource Management, Division of Fisheries, Illinois Department of Conservation, Springfield. FLOWING WATERS Black bass Cotfish 50.0% Walleye/Seuger POSS Crappie Percentage of total angling days annually Figure 17. Hierarchy of the most sought sport fish species in Illinois, 1977-1989. This figure demon- strates that catfish species continually receive the highest fishing pressure, approximately 40% of the total number of angling days. Fishing pressure on black bass species has steadily increased since 1977. Wallye/sauger and crappie were the third or fourth most preferred species during this period. Although the popularity of these species does seem to be constant, it is important to realize that each year the absolute pressure received by any one of these species is rising. The IDOC immediately investigates all reported fish kills and files a report including, when possible, an assessment of the probable cause of the high fish mortality. These records, then, serve as a rough index of one aspect of the relationship between Illinois and its flowing waters. Between 1962 and 1991, an annual average of 19.6 fish kills that could be attributed to non-natural causes were reported from flowing waters in Illinois. These kills resulted on average in the loss of 532,000 fish annually. The data suggest that the annual number of fish kills has not declined over time; rather, there has been a trend toward an increased number of pollution-caused fish kills per year (Figure 18). The mean number of kills in the first 15 years of the 30-year period (17.9 + 1.9 [SE]) is less than the mean number in the past 15 years (21.4+ 2.1 [SE]). Since 1966, the number of fish kills reported per year has increased significantly (linear regression; P < .05) despite large year-to-year fluctuations, There has been no obvious trend in the estimated number of fish killed per year (Figure 18). It is often difficult to ascertain the cause of a given pollution-caused fish kill, but two trends in the data seem apparent. The proportion of kills attributed to 184 NUMBER OF kILLS 1000 100 TOTAL FISH KILLED (thousands) 3 65 70 iiss 80 85 90 YEAR Figure 18. (A) The number of pollution-caused fish kills and (B) the estimated total number of fish killed in those events in Illinois streams between 1962 and 1991. Source: Illinois Department of Conservation annual reports. industrial pollution has declined steadily over the 30- year period and has leveled off at around 10% per year (Figure 19). At the same time, the proportion of kills attributed to agricultural pollution has increased steadily, at least through the mid-1980s (Figure 19). These trends are consistent with developments in water-quality standards and agricultural practices during the period. Stricter standards on the quality of water discharged into streams by industrial and municipal users began to be enforced during the 1960s, while the application of ammonia fertilizers, herbi- cides, and, to a lesser extent, pesticides on agricultural land has increased markedly in the past 30 years, especially during the 1960s and 1970s (see chapter on agricultural lands). Agricultural impacts (e.g., from runoff of ammonia), in contrast to the typical industrial and municipal situation, can rarely be associated with a single point of discharge into a stream. Such non-point sources of pollution remain a major threat to the integrity of Illinois’ flowing waters. @ agricultural V industrial PERCENT @ municipal Vv unknown YEAR Figure 19. Percentage of all pollution-caused fish kills attributed to (A) agricultural and industrial pollution and (B) municipal pollution and unknown causes in Illinois streams between 1962 and 1991. Source: Illinois Department of Conservation. Commercial Fish Harvest A number of rivers in Illinois are exploited by commer- cial fisherman, but only four support fisheries of significant size and have been monitored more or less continuously by the Illinois Department of Conserva- tion. These are the Mississippi, Illinois, Kaskaskia, and Wabash rivers. Data reported here for each of these rivers include both total catch (measured in pounds) and total value of catch reported as 1990 dollars. Value for catch was derived by multiplying reported data on fish caught by the average price per pound offered by fish buyers (obtained from phone surveys) for each year reported. Catch is divided by species or group. These include buffalo (a combined catch of bigmouth buffalo [Ictiobus cyprinellus}|, smallmouth buffalo [/. bubalus), and black buffalo [/. niger]), carp (common carp [Cyprinus carpio]), catfish (a combined catch of FLOWING WATERS channel catfish [Jctalurus punctatus}, blue catfish [J. furcatus), and flathead catfish [Pylodictis olivaris}), drum (freshwater drum [Aplodinotus grunniens]), sturgeon (primarily shovelnose sturgeon [Scaphirhynctius platorhynchus}), and paddlefish (Polyodon spathula). The “others” category in the figures includes a variety of species taken in relatively small amounts, such as bullheads (combined catch of a number of Ameiurus species), white carp or carpsuckers (combined catch of quillback and other native carpsucker species [Carpoides]), gars (Lepisosteus spp.), and mooneye (combined catch of mooneye [Hiodon tergisus] and goldeye [H. alosoides}). Since the late 1970s, the non-native grass carp (Ctenopharyngodon idella) has also shown up in significant quantities in commercial catches, increasing from about 3000 pounds in 1975 to over 15,000 pounds in 1991. Catch data are summarized in Figures 20—25. Caution should be exercised in deriving inferences about fish population dynamics from these data because no data are presented on fishing effort ex- pended to obtain a particular level of catch. Total catch from all significant river fisheries ranges from 2.7 to 5.6 million pounds, generating an average yearly income of approximately $1.2 million. Across all river fisheries, two consistent trends were (1) the relative decrease in the importance of the carp fishery and (2) an increase in the importance of catfish. It is important to note that the two most valuable groups to the commercial fishery, the buffalo and the catfish groups, are native species. Commercial Harvest of Freshwater Mussels Pearl Button Industry. Freshwater mussels have been important economically at various times throughout history. John Boepple, a button maker from Germany, pioneered the use of freshwater mussels for buttons and began operating the first freshwater pearl button company in Muscatine, Iowa, in 1891 (O'Hara 1980). The button industry grew rapidly into a multimillion- dollar operation, and by 1908, it had a capital invest- ment of over $2 million and an annual output of $6 million (Davidson 1924). Every town along the river, large or small, was in some way connected with the button industry (Coker 1919). In the early 1890s, when mussel fishing began at New Boston, Illinois, about 20 miles downstream from Muscatine, clammers har- vested up to a ton a day, but by 1898, they had diffi- culty getting a ton in a week (Smith 1899). The mussel fishery and button industry rapidly expanded north and south on the Mississippi River and over to the Illinois River as mussel beds were depleted. 185 FLOWING WATERS Mississippi Illinois Total Catch (million pounds) SEE EE EEE ~~ o Total Value (Million Dollars) o a eeeeeie 1 “14970 1975 1980 1985 1990 Year Figure 20. Total catch af all species (top) and 1990 dollar value of that catch (bottom) for the Illinois and Mississippi rivers from 1971 through 1991. The Mississippi River clearly supports the largest commer- cial fishery in the state, typically providing catches more than twice as large as those from the second largest fishery, the Illinois River. Mississippi River catches are variable, averaging around 3 million pounds per year. Catches appeared to exhibit a slow decline until 1980 (2.1 million pounds), after which they increased steadily through the 1980s, obtaining their highest peak in 1989 (4.4 million pounds). Illinois catches average about 650,000 pounds per year. From 1981 through 1986 catches remained relatively high, peaking at over 1.55 million pounds in 1986. Illinois River catches are still small compared to historical records indicating catches of over 17 million lb in 1908 and 5.6 million lb in 1950 (Starrett 1972). Mississippi catches have not varied as greatly from historical values, which ranged between approximately 3 and 4 million pounds from 1950 to 1970 (Sparks 1982). Value of catch for both rivers show less variation than total catch reflecting composition of catch and chang- ing market prices. The Mississippi River provides a relatively consistent income of approximately $950,000 / year, whereas the Illinois generates about $227,000 / year. 186 200 | Wabash — Total Catch (thousand pounds) 450 | Kaskaskia 100 50 | 0 eee ey os Total Value (thousand dollars) 1970 1975 1980 1985 1990 Year Figure 21. Total catch of all species (top) and 1990 dollar value of that catch (bottom) for the Wabash and Kaskaskia rivers from 1971 through 1991 (breaks represent years where no catch data was obtained). Kaskaskia River catches exhibited extreme variation, ranging from 12,000 to almost 300,000 lb. Catches increased dramatically after 1978, peaking in 1982 and 1983, then declining to approximately 110,000 lb / year afterward. Wabash River catches were much more consistent, varying from a low of 34,000 lb in 1980 to a high of 103,000 lb in 1984 with no clear upward or downward trends. Value of catch for both rivers tracks variation in catch reflecting composition of catch and changing market prices. The Kaskaskia River during 1982-1991 provided an average income of approxi- mately $46,000 / year, whereas the Wabash has generated an average of $37,500 / year since 1971. Value of Catch (thousand dollars) 2.0 Carp Buffalo Drum Catfish Other Sturgeon/Paddlefish BS = SS, ee Sa a ae 3 3 21.5 § = Seo § a} 3 0.5 EE EOS AP A eh a 0.0 Sa g & r=) Figure 22. Catch (top) and 1990 dollar value of catch (bottom) for the dominant fish groups exploited by commercial fishermen in Mississippi River from 1971 through 1991. Carp and buffalo make up the bulk of the fishery, with carp being the predominant species taken before 1978 and buffalo predominating in the late 1980s. Catfish and drum are the next most important groups with catfish increasing steadily in importance since 1980. Catfish are also an important gamefish species in many rivers, and the potential for conflicts between sport and commercial fisheries is perhaps highest with this group. Sturgeon, paddlefish, and a variety of other species (carpsuckers, bullheads, mooneye, etc.) contribute small but consistent catches to the fishery. Although catfish are caught in smaller quantities than carp or buffalo, they consistently contribute the most value to the fishery, followed by buffalo and then carp. The value of carp and drum to the fishery appears to be declining, whereas the value of sturgeon, paddlefish, and other species appears to have remained relatively stable over the past 20 years. FLOWING WATERS Carp Buffalo Drum Catfish Other Sturgeon/Paddlefish 1.2 > e+e oO ae Total Catch (million pounds) Value of Catch (thousand dollars) Figure 23. Catch (top) and 1990 dollar value of catch (bottom) for the dominant fish species exploited by commercial fishermen in Illinois River from 1971 through 1991. Buffalo is the predominant group caught in the Illinois River since the mid-1970s, and catches of this group increased dramatically in the 1980s declining after 1987. Carp were the second most abundant species in the fishery, although catfish (which have been steadily increasing in abundance) appear to be eclipsing carp in importance after 1988. Paddlefish and sturgeons do not represent a significant fishery in the Illinois River. Drum and other species contribute only very small amounts to the fishery. In terms of dollar value, buffalo is also the predominant group in the Illinois River. The value of this fishery closely tracks abundance in catch suggesting relatively stable prices for species over the past 20 years. Catfish are the next most valuable species, with a contribution approaching that of buffalo in some years. The value of the carp fishery approached that of catfish in the 1970s, but since 1982 the relative importance of this fishery appears to be diminishing. The remaining species combined contribute less than $50,000/year to the fishery. 187 FLOWING WATERS >t | Carp Buffalo Drum Catfish Other Sturgeon/Paddlefish - © ce -e -e is 8 = on Total Catch (thousand pounds) 3 s ~ px 0 ee SS = = oi aa 3 e- o T 8 NO o 10 Value of Catch (thousand dollars) as C Se oe. A 1970 1975 1980 98 1990 Figure 24. Catch (top) and 1990 dollar value of catch (bottom) for the dominant fish species exploited by commercial fishermen in the Kaskaskia River from 1974 through 199] (data were not obtained from this system in 1977). Since 1981, buffalo has been the predominant fish group caught in the Kaskaskia River, which has yielded as much as 160,000 pounds of this species. As in the Illinois River, catches of carp have diminished while catches of catfish have remained relatively constant or shown upward trends. Other species including drum, paddlefish, etc., contribute relatively little to this fishery. Buffalo generated the most value in the fishery from 1983 to 1990, but value of catfish to the fishery has remained relatively constant while buffalo has been highly variable. Value of carp to the fishery appears to be decreasing steadily since 1983. Other fish species combined yield less than $3,000 / year to the fishery. 188 8 Carp Buffalo Drum Catfish Other Sturgeon/paddlefish - SO Dal bak hoon foo a Bd Da Df td De CC ot bat bar be POEL br OL te 0 Oo N a ‘oO 0 So Nn st ie) oo o Xn al | n -_ om “ L n _ Nn N nN nN nN ao a tal mn om at st L sd Ld i al oo ao co oo oo n Sa rh See Si ON Sa kes Ona CNC ON Oy SSN Ose ONO Oya OMCs ON YEAR 800000 700000 700000 a 600000 600000 500000 500000 400000 ea 3 400000 3 — = 300000 300000 —— 200000 i sae) 200000 100000 100000 0 0 1987 1988 1989 1990 1987 1988 1989 1990 Iinois River Th idge H Mississippi River Threerid ge Harvest (D)_ Dead Shells HB Live Shells 600000 2500000 500000 me=e 2» 400000 1500000 300000 a 3 1000000 200000 100000 500000 0 0 1987 1988 1989 1990 1987 1988 1989 1990 Illinois River Washboerd Harvest Mississippi River Washboard Harvest Figure 26. (A) Commercial harvest of mussels in the Mississippi River in terms of pounds harvested and dollar value. (B,D) Harvest of live and dead shell of threeridge in the Illinois and Mississippi rivers, respectively. (C,E) Harvest of live and dead shells of washboard in the Illinois and Mississippi Rivers, respectively. 190 FLOWING WATERS 60000 60000 50000 50000 40000 40000 B 30000 B 30000 20000 20000 10000 10000 0 0 1987 1988 1989 1990 1987 1988 1989 1990 Dlinois River Misc. Species Harvest Mississippi River Misc. Species Harvest 1200000 3000000 1000000 2500000 800000 2000000 B 600000 B 1500000 400000 1000000 200000 500000 v1) v0) 1987 1988 1989 1990 1987 1988 1989 1990 Illinois River Harvest - All Species Mississippi River Harvest - All Species $1200000 $2000000 $1800000 ped $1600000 $1400000 $800000 $1200000 $600000 $1000000 $800000 $600000 $200000 $200000 so so 1987 1988 1989 1990 1987 1988 1989 1990 Illinois River Total Harvest Mississippi River Total Harvest Figure 27. (A,B) Commercial harvest of miscellaneous mussel species in the Illinois and Mississippi rivers, respec- tively. (C,D) Total commercial harvest (in pounds) of all species in the Illinois and Mississippi rivers, respectively. (E,F) Dollar value of the total commercial harvest of mussels in the Illinois and Mississippi rivers, respectively. 191 FLOWING WATERS pounds and was valued at $9.6 million. Illinois represents the largest percentage (42%) of the harvest, followed by Iowa (34%), Wisconsin (20%), Missouri (5%), and Minnesota (< 1%). In 1989, the 3.7 million pounds of mussels harvested from the Illinois and Mississippi rivers had an approxi- mate value of $1.5 million (Figure 27). Over 3.4 million pounds of mussels was harvested in 1990 and was valued at $2.9 million. A two- to threefold increase in the price paid for washboard (Megalonaias nervosa), an increasingly less common commercial species, caused this near doubling in value despite a 9% decrease in the number of mussels harvested (in pounds). As washboard availability decreased, threeridge harvest nearly doubled. It is doubtful that mussel populations are sustainable at this level of harvest, and trends should be analyzed carefully to determine whether further regulations are required. The Future of Commercial Mussel Harvest. Project- ing changes in the commercial mussel fishery over the next 10 years is difficult because of the large number of influencing variables, including market demand, cost of licenses, changes in minimum size limits, and changing habitat conditions. Potentially, the greatest threat to the native Illinois mussel fauna will be the impact caused by the introduction of the zebra mussel (Dreissena polymorpha) to the Mississippi River drainage in 1991. The freshwater mussel fauna of the Great Lakes has already suffered a devastating decline due to this exotic (Hunter and Bailey 1992). Recommendations for future mussel management on the Upper Mississippi River include standardized sheller and buyer report forms, development of more uniform regulations, and continued implementation of the strategic mussel plan goals (Fritz 1990). Some of the high-priority objectives of the plan are to develop a solid base for funding and to continue research in areas such as life histories, status surveys, and the effect of commercial impacts and the zebra mussel on freshwa- ter mussel populations. Most of the data from this section on mussel harvest was excerpted from a paper by P. Thiel (U.S. Fish & Wildlife Service) and B. Fritz (Illinois Department of Conservation [retired]) presented at a symposium titled “Conservation and Management of Freshwater Mus- sels” held in St. Louis, Missouri, in October 1992. Their help is greatly acknowledged. 192 TRENDS IN BIOLOGICAL COMMUNITIES Fish: Statewide Native Fishes Reproducing in Illinois. At the turn of the century, 187 native fishes were reproducing in Illinois (Forbes and Richardson 1908). By 1979, eight native fishes had been extirpated (Table 2; Smith 1979). By 1993 (only 14 years later), another five species had disappeared from the state (Table 2), resulting in a total loss of 7% of the fauna present at the start of the century. Several factors are responsible for the disappearance of native fishes (Smith 1971, Burr 1991, Page 1991). Principal among them are excessive siltation associated with the pervasive nature of agriculture in Illinois; the drainage of bottomland lakes that serve fishes as spawning areas, nurseries, and overwintering refuges; water pollution; stream desiccation that follows the lowering of the water table as groundwater is removed for agriculture and municipalities; competition and predation by introduced species; and dams that convert streams into standing water. These factors continue to affect Illinois streams, and another 28 species of fishes, listed as endangered or threatened species (Table 3), are in imminent danger of disappearing from Illinois. Non-native Fishes Reproducing in Illinois. At the turn of the century, only one non-native species of fish, the carp, was reproducing in Illinois (Forbes and Richardson 1908). By 1979, eight non-native fishes were reproducing in Illinois (excluding four salmonids [chinook salmon, coho salmon, rainbow trout and brown trout] and one catfish [the white catfish] that were present in the state as the result of introductions but were not sustaining their own populations) (Smith 1979). By 1993, only 14 years later, eight more non- native fishes were established (Table 4), for a total of 16 species (not counting six introduced, but not self- sustaining, salmonids in Lake Michigan). Five of the 16 species reached Illinois from Atlantic Slope drainages following construction of the Welland Canal (built in the 1820s to connect Lake Ontario with Lake Erie and allow ships to bypass Niagra Falls), three species have escaped from ponds and aquariums, four species were stocked in Illinois in an effort to improve fishing, and the remaining species were either accidentally introduced (rudd, silver carp, and possibly inland silverside) or introduced to help control aquatic vegetation in fish culture ponds (bighead carp). The five species that reached Illinois via the Welland Canal Table 2. Extirpated species of native Illinois fishes. Species lost by 1979 Ohio lamprey, /chthyomyzon bdellium Blackfin cisco, Coregonus nigripinnis Muskellunge, Esox masquinongy Rosefin shiner, Lythrurus ardens Gilt darter, Percina evides Saddleback darter, Percina ouachitae Crystal darter, Crystallaria asprella Spoonhead sculpin, Cottus ricei Additional species lost by 1993 Alligator gar, Atractosteus spatula Bigeye chub, Hybopsis amblops Bluehead shiner, Pteronotropis hubbsi Northern madtom, Noturus stigmosus Harlequin darter, Etheostoma histrio are the sea lamprey, alewife, threespine stickleback, rainbow smelt, and white perch. The pond/aquarium escapees are the goldfish, Oriental weatherfish, and Rio Grande cichlid. Species introduced in efforts to improve fishing in Illinois are the carp, grass carp, threadfin shad, and striped bass. Native Fishes with Expanding Illinois Distributions. Although many fishes have experienced range reduc- tions in recent decades, a few species have expanded their ranges in Illinois in response to environmental changes (Table 5). The red shiner (Cyprinella lutrensis) has spread through much of central Illinois (Page and Smith 1970), north into Wisconsin, and up the Ohio River drainage of southern Illinois into Kentucky and the lower Wabash River (Burr 1991). The generally eastern movement of the species is thought to be related to environmental changes that favor species tolerant of wide fluctuations in pH, dissolved oxygen, and temperature (Matthews and Hill 1977). Other species (e.g., the suckermouth minnow, Phenacobius mirabilis, and bigmouth shiner, Notropis dorsalis), show a similar eastward-expanding pattern. Several sport fishes and fishes used for bait, especially the fathead minnow (Pimephales promelas), have experienced range expansions as a result of efforts to improve sport fishing. The channel catfish (/ctalurus punctatus) and black crappie (Pomoxis nigromaculatus) recently have been found in Lake Michigan but were not known there when Smith (1979) FLOWING WATERS Table 3. Threatened and endangered Illinois fishes. Endangered species Northern brook lamprey, /chthyomyzon fossor Bigeye chub, Hybopsis amblops Pallid shiner, Hybopsis amnis Pugnose shiner, Notropis anogenus Bluehead shiner, Pferonotropis hubbsi Weed shiner, Notropis texanus Cypress minnow, Hybognathus hayi Greater redhorse, Moxostoma valenciennesi Northern madtom, Noturus stigmosus Western sand darter, Etheostoma clarum Eastern sand darter, Etheostoma pellucidum Bluebreast darter, Etheostoma camurum Harlequin darter, Etheostoma histrio Threatened species Least brook lamprey, Lampetra aepyptera Lake sturgeon, Acipenser fulvescens Alligator gar, Lepisosteus spatula Cisco, Coregonus artedii Lake whitefish, Coregonus clupeaformis Bigeye shiner, Notropis boops Ironcolor shiner, Notropis chalybaeus Blackchin shiner, Notropis heterodon Blacknose shiner, Notropis heterolepis River redhorse, Moxostoma carinatum Longnose sucker, Catostomus catostomus Banded killifish, Fundulus diaphanus Spotted sunfish, Lepomis miniatus Bantam sunfish, Lepomis symmetricus Iowa darter, Etheostoma exile surveyed the fishes of Illinois. The mosquitofish (Gambusia affinis) has been transplanted north of its native range in an effort to control mosquito populations. In some instances range expansions are associated with range contractions in other species. The expansion in Illinois of the red shiner has been accompanied by a contraction in the range of two closely related native species, the spotfin shiner, Cyprinella spiloptera, and the blacktail shiner, Cyprinella venusta (Figure 28). With the loss of riparian vegetation, Illinois streams have become more turbid and variable in temperature, favoring the reproductive success of the environmen- tally tolerant red shiner over that of other species. As streams further degrade and populations of the red shiner increase, spotfin and blacktail shiners are unable to compete, and they disappear (Page and Smith 1970). 193 FLOWING WATERS Table 4. Non-native fishes reproducing in Illinois. Species established by 1979 Sea lamprey, Petromyzon marinus Alewife, Alosa pseudoharengus Threadfin shad, Dorosoma petenense Rainbow smelt, Osmerus mordax Carp, Cyprinus carpio Goldfish, Carassius auratus Grass carp, Ctenopharyngodon idella Striped bass, Morone saxatilis Additional species established by 1993 Bighead carp, Hypophthalmichthys nobilis Silver carp, Hypophthalmichthys molotrix Rudd, Scardinius erythrophthalmus Oriental weatherfish, Misgurnus aguillicaudatus Inland silverside, Menidia beryllina Threespine stickleback, Gasterosteus aculeatus White perch, Morone americana Rio Grande cichlid, Cichlosoma cyanoguttatum Fish: Champaign County Four intensive surveys of stream fishes in Champaign County were completed at 30-year intervals beginning in the late 1890s (Figure 29). Cumulative fish species numbers by survey only varied between 55 and 61 (54 and 59 indigenous taxa) from a pool of 81 taxa that were recognized at the turn of the century. However, sampling efficiency varied greatly among techniques, which were less efficient in the earlier surveys. After correcting for species richness efficiency for each sample, mean numbers of indigenous species per sample declined greatly between 1928 and 1959 (Figure 29), a period during which row-crop agricul- ture was extended and intensified; also, chemical pollution of streams reached unprecedented levels by the late 1950s. A slight increase was suggested between 1959 and 1987. Paired sample analysis revealed that the biomass of various species (small- mouth bass, channel catfish, and grass pickerel) had increased significantly (P<0.005 after Bonferroni correction) during this period, an improvement that was probably due to an improvement in water quality since the dreadful conditions that existed in the 1950s and 1960s. However, physical habitat conditions have not improved during this period, during which riparian forest cover diminished (Osborne et al. 1991) and the physical effects of row-crop agriculture had not changed. Evidently, conditions for stream fish were much better during the first two surveys (Figure 29) 194 Table 5. Examples of native fishes with expanding Illinois ranges. As a result of deliberate introductions as sport fishes Channel catfish, /ctalurus punctatus Redear sunfish, Lepomis microlophus Black crappie, Pomoxis nigromaculatus As a result of deliberate introductions as forage for sport fishes Fathead minnow, Pimephales promelas As a result of deliberate introductions for pest control Mosquitofish, Gambusia affinis As a result of environmental changes Silverjaw minnow, Ericymba buccata Bigmouth shiner, Notropis dorsalis Red shiner, Cyprinella lutrensis Suckermouth minnow, Phenacobius mirabilis Banded darter, Etheostoma zonale even though extensive wetland drainage, tiling, and channelization had occurred before the 1890s. Fish communities have also changed during the past 90+ years. In general, the percent occurrences of species have diminished (Figures 30 and 31), espe- cially considering that the earlier two surveys used less efficient sampling methods. However, some species appeared to increase (Figure 32), including the intro- duced common carp. If these increases are not artifacts of increasing sampling efficiency, some interpretations are possible. Bluegill escape from impoundments and borrow pits, which have increased during the past 35 years. The creek chub and striped shiner are examples of minnow species tolerant of streams with low habitat quality, and the blackstripe topminnow is tolerant of low oxygen conditions, which frequently occur as a result of excess inorganic nutrients from agriculture and sewage treatment plants. In conclusion, a strong trend in species richness was evident in which the mean number of fish species per sample descreased by a quarter between 1928 and 1959. This is attributed mainly to degradation in physical habitat and water quality due to changes in agricultural practices. No change in richness was noted since 1959, but the biomass of some piscivores increased. Percent occurrences of many species decreased during the 90-year period sampled, while tolerant species, such as creek chub, striped shiner, and the common carp (an exotic) increased. G \ O Be eek ia 8} terns) pe Y FLOWING WATERS Figure 28. Distribution of Cyprinella lutrensis (left) and Cyprinella spiloptera (right). Open circles denote 1908 locality records; solid circles denote locality records from 1950 to 1969. The shaded areas in the left figure indicate the major range expansions that occurred from 1908 to the present. The shaded area in the right figure indicates the range reduction that occurred from 1908 to the present. Fish: Illinois River Background. The Illinois River belongs to a world class of large river—floodplain ecosystems, where biological productivity (including fish yield) is enhanced by annual flood pulses that advance and retreat over the floodplain and temporarily expand backwaters and floodplain lakes (Junk et al. 1989, Sparks et al. 1990, Sparks 1992). The expanded aquatic habitats are utilized as feeding areas by migratory birds and as breeding areas and nurseries by fish and other aquatic life. The Illinois River today is the largest river (in terms of water flow) contained mostly within the state, and its fish populations reflect urban influences from the state’s largest metropolitan area (the Chicago- Joliet area) as well as effects of land-use practices in the corn belt that runs across the middle of the state. The river is divided into five reaches by navigation dams, including the Alton Dam (Dam 26) on the Upper Mississippi River, which influences the lower 80 miles of the Illinois River (Figure 33). These five reaches in turn fall into three major sections, defined by the natural physiography of the river and by the degree and nature of human alterations. The Dresden, Marseilles, and Starved Rock reaches together form the upper Illinois River, characterized by a geologically young channel with a relatively narrow floodplain between rocky bluffs. This section has been heavily influenced historically by effluents from the Chicago-Joliet area. The La Grange and Peoria reaches constitute the middle river. Here the river occupies a broad floodplain (2 to 5 miles wide) created by the ancestral Mississippi and Ohio rivers. Approximately half of the floodplain and the natural backwaters and lakes remain along this 195 —______ FLOWING WATERS (4S) == Sr T T T T itis “0 aT T w = = =< nn a Ww a a 20 a “ 2) =] 3 Zz w 9 a z o 15 z 1 r n + ae n n n mn 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 YEAR Figure 29. Mean numbers of indigenous fish species per sample after correction for gear efficiency for each of four surveys in Champaign County streams. The number of samples for each survey were as follows: 1898 (Forbes and Richardson), 46 samples (seine net); 1928 (Thompson and Hunt), 131 samples (seine net); 1959 (Larimore and Smith), 199 samples (electric and net seine); 1987 (Osborne and Bayley), 141 samples (mostly electric seine). Error bars are standard errors. Common carp and redear sunfish, which are exotic species, were not included. Eighty-one different fish taxa were collected during the 90-year period. This included eight “species pairs,” such as orangethroat and rainbow darters, because confusion between certain species was evident due to the limited taxo- nomic knowledge at the turn of the century. These pairs were maintained in analyses in subsequent surveys in which both species were recognized, so that changing species richness was not a function of increasing taxonomic knowledge. section. In contrast, most of the floodplain and backwa- ters have been drained in the lower river (the Alton reach), and the river channel runs between two levees until it nears the confluence with the Mississippi River. Stresses. Major historical stresses on the ecosystem include the following: (1) drainage of wetlands and channelization of tributaries in the drainage basin, mostly in the late 1800s but continuing to the present; (2) the diversion of Chicago sewage and industrial effluent from Lake Michigan to the Illinois River, via a system of waterways, starting in a major way in 1900; (3) leveeing and draining of half the floodplain in the 1920s, primarily for agriculture; (4) completion of the 196 100 ay i, T ag 1S T T T T roa) © o o = T 6 o BS [o) 20 PERCENT OCCURRENCE AMONG SAMPLES 1890 1900 1930 1960 YEAR 1990 Figure 30. Percent occurrence among nonreplicated samples of selected fish species in Champaign County streams from four surveys (see references cited in Figure 29 legend; see also Bayley et al. 1989 and Bayley and Dowling 1990). Each species indicated a highly significant (P<0.01) difference among surveys (Bonferroni adjustments for multiple testing were applied) but not necessarily a trend with time. Different sampling effiencies affect probability of capture: solid symbols correspond to species in which efficiencies were 5—10 times lower using seine nets (which were used exclusively in the first two surveys) compared to the electric seine (which dominated the last two surveys); open symbols indicate similar efficiencies; shaded symbols indicate that seine net efficiencies were 2-5 times lower. Therefore, the darker the symbol, the greater percent occurrences were underestimated during the first two surveys. JOD = johnny darter (Etheostoma nigrum), GOS = golden shiner (Notemigonus crysoleucas), BLD = blackside darter (Percina maculata), BLD = black bullhead (Ameiurus melas). federal 9-foot navigation project in the 1930s; (5) intensification of agriculture in the 1950s, resulting from the shift from small grains, orchards, and pastures to row crops, and introduction of practices such as fall plowing and use of pesticides and chemical fertilizers; and (6) development of an industrial corridor (chemical manufacturing, petroleum refining, and storage of agricultural chemicals) in the 1950s along the upper river and its Des Plaines tributary in the vicinity of Joliet. Upland drainage and channelization of tributar- ies probably increased the rate of delivery of water, sediment, and pollutants to the main river. Diversion of sewage and Lake Michigan water raised mean water levels, caused the less flood-tolerant trees to die back PERCENT OCCURRENCE AMONG SAMPLES 100 o °o a oO > oO nN o 1890 1900 1930 1990 YEAR 1960 Figure 31. Percent occurrence among nonreplicated samples of selected fish species in Champaign County streams from four surveys (see references in legends of Figures 29 and 30) Each species indicated a highly significant (P<0.01) difference among surveys (except SVM which disappeared in the 1980s) (Bonferroni adjustments for multiple testing were applied) but not necessarily a trend with time. Different sampling effiencies affect probability of capture: solid symbols correspond to species in which efficiencies were 5-10 times lower using seine nets (which were used exclu- sively in the first two surveys) compared to the electric seine (which dominated the last two surveys); open symbols indicate similar efficiencies. Therefore, the darker the symbol, the greater percent occurrences were underestimated during the first two surveys. SJM = silverjaw minnow (Ericymba buccata), ORS = orangespotted sunfish (Lepomis humilis), SDS = spotted sucker (Minytrema melanops), SVM = silvery minnow (Hybognathus nuchalis). on the floodplain, and eventually degraded water and sediment quality (Mills et al. 1966). Drainage projects on the floodplain reduced fish and wildlife habitat and the capacity of the floodplain to convey or store flood water and concentrated sedimentation in the areas that remained open to the river. The navigation dams permanently inundated portions of the floodplain, so the soils do not dry and compact as they once did during low river stages in midsummer (Bayley 1991). Also, the wind fetch was greater on the expanded lakes and backwaters, so the heights of wind-driven waves increased and thereby increased resuspension of the unconsolidated sediments. The improved navigation system stimulated boat traffic, which also generated FLOWING WATERS 100 "a i ; T 2 T T » (ae T a = 80 “” i<] z o = 60 y é <= 40 Oo 8 z 20 8 & 0 1890 1900 1930 1960 1990 YEAR Figure 32. Percent occurrence among nonreplicated samples of selected fish species in Champaign County streams from four surveys (see references in legends of Figures 29 and 30) Each species indicated a highly significant (P<0.01) difference among surveys (Bonferroni adjustments for multiple testing were applied), but not necessarily a trend with time. Differ- ent sampling effiencies affect probability of capture: solid symbols correspond to species in which efficien- cies were 5—10 times lower using seine nets (which were used exclusively in the first two surveys) com- pared to the electric seine (which dominated the last two surveys); open symbols indicate similar efficien- cies. Therefore, the darker the symbol, the greater percent occurrences were underestimated during the first two surveys. CRC = creek chub (Semotilus atromaculatus), STS = striped shiner (Luxilus chrysocephalus), BLT = blackstripe topminnow (Fundulus notatus), CAP = common carp (Cyprinus carpio), BLG = bluegill (Lepomis macrochirus). waves that resuspended sediments and contributed to bank erosion. Intensification of agriculture, coupled with stream channelization and removal of riparian vegetation, increased the rate at which water and sediments, and chemicals associated with them, were delivered to the river. The expansion of chemical handling and manufacturing on the upper river in- creased the risk of both chronic pollution and spills. Response of Fish Populations to Recent Stresses. - i vey. The fish populations of the Illinois River have been surveyed annually since 1957, except for a few years when no funding was available or sampling could not be 197 FLOWING WATERS conducted because the river was in flood. The sampling is conducted at 28 permanent locations in the fall, using an electrofishing boat, when water levels are maintained at stable, low elevations by the navigation dams (Figure 33). Two stations are located in the Upper Mississippi River, near the confluence with the Illinois, for comparison (Figure 33). The entire data set has only recently been transcribed to computer disks and is still being verified against the original field data sheets. Although comparisons of the occurrence and general abundance of fishes can be made reliably across all the years (Tables 6-8), other comparisons are based on two years, 1963 and 1992, for which data are fully verified. We believe these two years are broadly representative of the condition of fish populations in the Illinois River at the beginning of the survey and in the most recent five years. Species Composition and Abundance. Ninety-one species of fishes from 18 families, and five hybrids, have been collected during the electrofishing survey from 1957 to 1992. Over the entire period, just five species dominated the upper river, with the introduced goldfish and carp ranking first and second in abun- dance (Table 6, Figure 34). In recent years however, native species have returned to the upper river, and the electrofishing catch is dominated by native minnows, green sunfish, and gizzard shad (Figure 34). Carp now rank seventh in abundance (5.3% of the catch), and native fishes such as smallmouth and largemouth bass and bluegill sunfish constitute 3 to 4.6% of the catch (Figure 34). Carp and goldfish are more tolerant than most native species of the low oxygen levels and toxic materials associated with heavy pollution loads, and their populations often expand in the absence of pollution-intolerant predators (e.g., the basses) (Lubinski and Sparks 1981). The change to a more balanced fish community dominated by native species reflects improvements in water quality, as corroborated by a decline since 1975 in the toxicity attributable to ammonia, which is associated with sewage effluents (Figure 35). Another indication of improvement was the collection, independent of the eiectrofishing survey, of three state-endangered fishes in the upper river in the period 1987-1989: the pallid shiner, river redhorse, and greater redhorse (Page et al. 1992). In contrast to dominance by only five species in the upper river, 12 species were regularly abundant in the middle river and 10 in the lower river during most of the 35-year period covered by the electrofishing (Tables 7 and 8). The common carp ranked first in abundance in the middle and lower river in 1963 but was superseded by the bluegill by 1992 (Figures 36 and 37). In the lower river, largemouth bass ranked fourth in abundance, 198 after gizzard shad and carp, and constituted 9% of the catch (Figures 36 and 37). Some species that were once common are now virtu- ally absent (Starrett 1971, Sparks 1977, Illinois Natural History Survey unpublished data). The yellow bass, northern pike, and black buffalo use flooded terrestrial or aquatic vegetation for spawning and may have declined because of alterations in the flood pulse or because of the loss of aquatic plants and general deterioration of shallow backwaters due to excessive sedimentation. External Abnormalities. The incidence of external abnormalities (eroded fins, sores) in the fish declined markedly between 1963 and 1992, indicating a general improvement in water quality. However, abnormalities occur more frequently in fishes that contact bottom sediments (catfish, carp) than in fish that occupy the water column (bass, bluegill), indicating that there are pollutants or pathogens associated with the sediments (Figure 38). Also, the incidence of abnormalities increased in the upstream direction in both 1963 and 1992, implicating the Chicago-Joliet area as the source of whatever causes the abnormalities. Body Condition. Fish biologists use a relative weight index (W _) to indicate the general condition of fish. A value of 1 indicates that the weight of the fish in relation to its length is comparable to the top quartile of the fish that have been sampled in the same geographic region. A value below | indicates that the fish is underweight and may not be growing well. In general, fish in the Illinois River that feed in the water column, such as bluegill, appear to be in good body condition, whereas fish that feed on the bottom, such as carp, are in relatively poor condition (Table 9). Starrett (1971) related the poor condition of bottom-feeding fishes to the lack of invertebrates (fingernail clams, aquatic worms, and insects) on the bottom of the river. The paucity of bottom-dwelling invertebrates was in turn linked to the occurrence of toxic levels of ammonia in the sediments (Figure 39). Sediment toxicity increased upstream, implicating the Chicago area as the likely source. Summary of Trends and Current Status. The relatively poor body condition of bottom-feeding fishes and the relatively high incidence of sores and eroded fins in fish that contact the bottom of the river indicate a lingering problem with sediments. A shift from dominance by goldfish and carp to a mixed community with substantial representation of native species, including sport fishes, indicates a general improvement FLOWING WATERS ____ Lake Michigan Mississippi River ee Des Plaines River. ;° | Brandon 1 ; Roads _Rock 12 ibn \ 14 Dresden Kankakee River i i i i i hora e~ i i i i | i @ Sampling Station St. Louis —/ 7 Lock and Dam Figure 33. Locations of the 28 sampling stations along the Illinois Waterway and Mississippi River. Stations 27 and 28 are on the Mississippi River, just below the confluence with the Illinois River. (Data from stations 27 and 28 are not used in the following analyses because data have been gathered for only a few most recent years. Future analyses will, however, use data from these stations as representing control sites [i.e., being least affected by pollution from the Chicago-Joliet area], for comparison with Illinois Waterway data). Stations I and 2 are on the Des Plaines River. The rest of the stations are on the Illinois River. The Illinois Waterway is divided into reaches defined by navigation dams. The Alton Dam on the Mississippi River also maintains water depths for navigation on the lower 80 miles of the Illinois River. In upstream order, the other dams and the reaches they control are as follows: La Grange, Peoria, Starved Rock, Marseilles, and Dresden. The reaches can be grouped based upon the amount of aquatic habitat (side channels, backwaters, and floodplain lakes) available per unit length of river as follows (data from Gilbertson and Kelly 1981): The upper river flows through a much narrower valley than the other sections and has the least amount of aquatic habitat, due to a different geologic history than the rest of the river. The middle river has the most aquatic habitat, while the lower river has had most of its floodplain aquatic habitat converted to agriculture, and is now more similar to the upper river in terms of available floodplain habitat. The gradient in the upper river is 1 to 2 feet per mile (200 to 400 cm/km), while the gradient in the middle and lower sections is only 0.1 to 0.2 foot per mile (20 to 40 cm/km.). in the water quality of the Illinois River. In addition to the intrinisic value of conserving and restoring native aquatic species in the Illinois River, there are recre- ational and economic benefits as well. As a result of improvements in water quality and fish populations, the river currently provides 2 million angling-days per year, valued at $40 million annually, based on 1989 figures (Conlin 1991). Sauger populations in the upper river and bass populations in the middle and lower river now support nationally ranked tournaments that are important to local and regional economies. Peoria, for example, will host a 1993 Bassmaster Superstars tournament, with the option to host it again in 1994 and 1995. Marketing studies indicate the Superstars tournament brings $6-8 million to the host city in expenditures by competing anglers, spectators, and news media, and the publicity boosts interest in outdoor recreation at the host site even after the 199 —_______ FLOWING WATERS Table 6. Presence (dark or stippled) or absence (blank) in the upper Illinois Waterway of commonly occurring fish species (species accounting for 95% of all individuals collec Species 57 58 59 60 61 62 63 64 65 66 67 68 69 7071 72 ted), 1975-1992.* Year Percentage of i 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 8889909192 Years Occuring Occurring in over 90% of years Gizzard Shad eee 2. 100.0 Common Carp rs aw 100.0 Emerald Shiner ss pireoe8 = Te 3) 100.0 Goldfish rr Ez 96.3 Green Sunfish SS eae TE OEE TS —“ "sR EA n= 9 - =-=<4 51.9 Smallmouth Bass ES Ea REO age Gr-- aig (CEEESSEEISSEDECEES 48.1 Freshwater Drum EQ EEEEEEEE -— (B88 SS fetes eee ce 444 White Crappie [se ES) EE}-— EGSSERESS} - -GEETEE)--— - EE] 40.7 Skipjack Herring fe (}-=>- RRR A PASE et 37.0 Bullhead Minnow ES ae --- GEl-~~-EEREEEESEET- 29.6 Yellow Bullhead Oe ee ates EEE} °-EEQ, ~~ 77 (EEEEESEES - 23.6 Bigmouth Buffalo oS ese MEE ees (EEESEEay -- BEERS} -—-—- 53 25.9 Red Shiner ---EE] EREEE]----- ac Aa Ea 22.2 Sand Shiner --E] JEEP CP i eee Ra Me a se OR em ESSEEy 222 Threadfin Shad SER: Voi eee Tee Wee es soace cleosle, Soautt cis coger tak ee waka 74 Bowfin (coe NRT Meola alin feo 3.7 Sauger SA oe) Stem Ril bib. Oo) eee |) Mk emer eta oo 0.0 * Black bars indicate species that occurred in over 90% of years. Stippled bars indicate species that occurred in less than 90% of years. Dashed lines indicate years when electrofishing was not conducted. Five species were consistently collected in 90% or more of all years, two of which, goldfish and carp, are pollution-tolerant, non-native species. Carp x goldfish hybrids were also collected in most years, a fish usually associated with polluted cond itions. Centrarchid species, usually identified as pollution- sensitive fishes (e.g., largemouth and smallmouth bass, bluegill, black crappie) have been collected more consistently since 1982 than in the earlier years of the survey, an indication of improved wa tournament (Conlin 1991; Jack Ehresman, Peoria Journal Star, personal communication). Prognosis. Despite the change to a better balanced fish community in the Illinois River over the past 30 years, with native species gaining in dominance over intro- duced species, problems remain. In addition to sedi- ment quality, these include introduction of additional non-native species, chemical contamination of fish, lack of critical information on fish and fisheries, general habitat deterioration and diminishment of the flood-pulse, and lack of a concept of what a river- floodplain ecosystem is, as a basis and guide for management and restoration. Non-native Species. It is ironic that improvements in waste treatment in the Chicago area lower the pollution 200 ter quality. barrier that once kept non-native species introduced to the Great Lakes from invading the entire Mississippi drainage via the artificial link to the Illinois River. The latest introduction is the European zebra mussel, first reported in the Illinois River in June 1991, now found throughout the Illinois River and at scattered locations in the Upper Mississippi, Ohio, and Tennessee rivers (Sparks and Marsden 1991, Sparks 1991). This mussel is capable of reaching densities of thousands per square yard and could have indirect effects on fish populations by altering the base of the food chain and smothering native mussel beds that some fishes use as spawning substrates. The white perch (originally from the Atlantic coast) has invaded the Illinois River from the Great Lakes within the past two years and the Euro- pean river ruffe (a small fish) is likely to follow soon. Invaders from the Mississippi include the Asiatic clam, Table 7. Presence (dark or stippled) or absence (blank) in the middle Illinois Waterway of commonly occurring fish species (species accounting for 95% of all individuals collected), 1975—1992.* FLOWING WATERS ____- Year Percentage of Species 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 Years Occurring Occurring in over 90% of years Gizzard Shad BS Eee MRE = ------- ess 100.0 Common Carp ee tC ens erty 100.0 Bigmouth Buffalo Pe :~—~CSCSC~S~S* Wess 100.0 Black Crappie Dn ee ee Saar 100.0 Emerald Shiner > aL aS 96.4 Smallmouth Buffalo eee = ------ Le SES al 96.4 Bluegill —— --- -— [eset nae 96.4 Largemouth Bass —— re es SEs 96.4 Channel Catfish ED es = =jhe ae = SS, 92.9 Green Sunfish re phat wale Dal 92.9 White Crappie eee a -—----- ES, 92.9 Freshwater Drum a as -------- awa 92.9 Occurring in less than 90% of years River Carpsucker EE} CREE) ~~ ~“Qe) GE (REE) -—- -EEE--—---- EEE) 89.3 White Bass -- GE] (ESE Eee ~~ ~~ Ree - ~~ - GEE -—----- | SERRA RARER | 89.3 Quillback ~~ EEE eieeeey ~~~") ESSE] GEEE--—-)«E)—s -- "~~" EEE] 88.5 Carp x Goldfish ugg SRPRAARRAAAAARARA AAA RAA LARA RRA RT palaialy COSRSROAREE | oeee etd wlereed os cart 328) raBRt| 85.7 Goldfish Ey “GEE §=— EEO“ EERE s=—“ GEE | 0.2) (Lubinski and Sparks 1981). Although there was a substantial decline in ammonia toxicity between 1975 and 1990, the trend of increased toxicity toward the Chicago area was Still evident in 1990. costs associated with replacing the functions once provided by the natural floodpulse of the river with human control (construction and maintenance of levees, operation of pumps and gates, production of fish in hatcheries for stocking in floodplain impoundments). Also, it is unlikely that the artificially maintained impoundments will provide the conditions necessary for maintenance of all the species of plants and animals that occurred in the natural river-floodplain ecosystem. Amphibians and Reptiles The herpetofauna of Illinois is relatively well known from Philip W. Smith’s 1961 monograph The Amphib- ians and Reptiles of Illinois. This work was based on a systematic survey that critically evaluated all known 204 collection records. Smith recorded 96 species in the state. Since 1961, distributions of many species have become significantly better known, and four additional species have been added to the state list (two sala- manders newly discovered in the state and two frogs that previously had been confused with others). Previous statewide species lists include those of Davis and Rice (1883), Garman (1892), and Cagle (1941). Morris et al. (1983) provide an annotated bibliography of Illinois herpetological data since Smith through 1980. Of the 100 species, 44 are represented in lotic systems (Tables 10 and 11). Disturbingly, at least one-third of these are currently at risk (Tables 10 and 11). Seven species are listed as threatened or endangered, and six more are on the watch list (two being considered for federal listing). As Smith (1961) pointed out, all of the herpetological habitats of Illinois are relict, because within historic times natural connecting habitats have been transformed into cities, industrial sites, cultivated fields, and greatly modified streams. No species is increasing its range or is becoming more abundant. General Comments. Amphibians require more moisture than most other tetrapods and exhibit great diversity in habitat of the adults, mode of reproduction, and habitats of the young, reflecting a spectrum of dependence upon bodies of water. In Illinois, they are found in and along the edges of a variety of lotic and lentic waters, including lakes, ponds, and streams. They occur in streams of all sizes, from headwater springs and caves to the mouths of large rivers. Three of the completely aquatic stream salamanders never transform. Because the skin of amphibians is a major respiratory organ that functions only when covered with moisture, they are in intimate contact with environmental water and are sensitive to contaminants and siltation. Reduction or loss of amphibian populations is a significant signal of environmental degradation. Many species of amphibians and reptiles live along the water/land interface, moving from one to the other as they eat and escape predators. Nearly all amphibians of lotic waters deposit aquatic eggs, and all have a larval stage lasting several months to a few years. Thus, their reproductive success and survival depend upon the availability of high-quality water containing suitable communities of food organisms. Worldwide Decline in Amphibian Populations. There is worldwide concern that populations of amphibians are declining over broad areas around the earth. International symposia and workshops, spon- FLOWING WATERS 1963 Channel Catfish (0.8%) Smallmouth Buffalo (1.0%) \ Black Crappie (4.0%) x Green Sunfish (1.6%) ~~ Largemouth Bass (1.6%) Bigmouth Buffalo (4.5%) Other (5.0%) Gizzard ROD Shad (41.0%) Bluegill (4.9%) ASX > Emerald Shiner (16.8%) Carp (22.0%) Smallmouth Buffalo (2.5%) eeecezes Channel Catfish (2.6%) Neetecatecanseas Black Crappie (2.7%) SRR SOS Bigmouth Buffalo (2.8%) wetetetetatatetetes River Carpsucker SR neeneeenN nae S\\ & | Bass (4.0%) x = Green Sunfish (9.1%) 1992 White Bass (2.3%) Other (4.6%) Bluegill (22.9%) Freshwater Oo OO os ay cen Drum <> © (6.2%) Emerald Shiner (9.9%) Carp (13.1%) Figure 36. Percentages of catches by species for the middle Illinois Waterway, for 1963 and 1992, based on number of individuals collected per hour of electrofishing. In 1963, 10 species accounted for 95% of all fish collected per hour, and catches were dominated by gizzard shad, carp, and emerald shiner. In 1992, 13 species accounted for 95.4% of all fish collected per hour, with bluegill being the most abundant, while gizzard shad, carp, and emerald shiner were reduced in numbers in comparison to 1963. Overall, percentages for each species in 1992 were more evenly distributed than in 1963, indicating no single species overwhelmingly dominated catches. Species are arranged in descending order of relative abundance in a clockwise direction and are labeled separately until approximately 95% of the pie is filled. sored among others by the National Science Founda- tion and the National Research Council, have focused on possible causes of decline and on strategies for obtaining relevant scientific documentation. Much of the decline is attributable to obvious destruction or degradation of natural habitats. Acid precipitation, pesticide release, agricultural practices, and exotic species introductions also have been implicated. In addition, amphibians are suspected to be particularly sensitive bioindicators of widespread, subtle ecological hazards such as increased ultraviolet radiation. Distin- guishing the effects of these factors from natural fluctuations in populations has been particularly difficult because of the dearth of baseline data. Estab- lishing a global monitoring program is a current effort of the ICUN Species Survival Commission’s Task Force on Declining Amphibian Populations. Mussels Freshwater mussels (Unionidae) are often used as indicators of water quality and have often been compared to the “canary in the coal mine” in determin- ing the health of the aquatic environment. Seventy- eight species of freshwater mussels have been reported from Illinois and boundary waters. Currently, only 63 species remain in Illinois, and 28 (44%) of those are considered to be either endangered (20 species), threatened (4 species), or on the watch list (4 species). Freshwater mussels are found in all of the medium to large rivers of Illinois and are occasionally present in creeks. Mussels are extremely long-lived, with some species reported to live over 50 years. They are filter feeders on detritus and plankton and constantly pump water through their bodies and sample their surround- ing environment. One of the more interesting aspects of their biology is their dependence on freshwater fish in order to complete their life cycle. 205 _____. FLOWING WATERS 1963 White Crappie (0.8%) Freshwater Drum (1.0%) Orangespotted \ Sunfish (2.1%) Pee White Bass (3.5%) Black Crappie (4.1%) Emerald Shiner (4.3%) Bluegill (4.5%) Yellow Bass (0.8%) Other (4.5%) Carp (33.8%) 1992 ; Other (4.1%) Green Sunfish (1.5%) pe a. Smallmouth Buffalo (4.4%) Freshwater Drum (4.6%) Bluegill (25.3%) Buffalo (6.4%) (7.0%) Gizzard Shad (32.2%) Channel Catfish (7.5%) Largemouth Carp (9.5%) Bass (9.0%) Figure 37. Percentages of catches by species for the lower Illinois Waterway, for 1963 and 1992, based on number of individuals collected per hour of electrofishing. In 1963, 11 species accounted for 95.5% of all fish collected per hour, with two-thirds of the catch being dominated by gizzard shad and the non-native carp (the most abundant fish). In 1992, 11 species accounted for 95.9% of all fish collected per hour; however, bluegill was the most abundant species. As in the middle waterway, percentages for each species in 1992 were more evenly distributed than in 1963, indicating no single species overwhelmingly dominated catches. Species are arranged in descending order of relative abundance in a clockwise direction and are labeled separately until approximately 95.5% of the pie is filled. Illinois has a long history regarding the study of freshwater mussels. Thomas Say, one of America’s first scientists and known as “the Father of Conchol- ogy” (the study of shells), first studied the mussels of the region in the early 1800s. Other scientists have conducted surveys and documented drastic declines in the freshwater mussel fauna over the past 175 years (Baker 1928, Parmalee 1967, Starrett 1971, Suloway et al. 1981). Because of the diligence of earlier workers, we have excellent data on the known historical fauna of many of the streams of Illinois. We have information on the distribution and abundance of mussels from the 1950s and 1980s for four rivers in Illinois: the Embarras, Little Wabash, Sangamon, and Kaskaskia. Using the same sampling methodology in both studies, we have documented huge reductions in mussel populations in all streams surveyed to date. A pronounced decline in the number of species was found in the four rivers mentioned above from around the turn of the century to 206 the 1950s (Figure 40). The number of species has remained fairly constant in the rivers studied from 1950 to 1990 with a slight increase in the Sangamon River and a decrease in the Kaskaskia River. The most pronounced reduction has come in the number of individual mussels found in these surveys (Figure 40). Some of the main factors responsible for the decline are siltation from agriculture and destruction of habitat through channelization and creation of impoundments. While the vast majority of mussel species have shown pronounced declines, a few species, particularly those adapted to live in mud or silt bottoms, have expanded their range and numbers in Illinois in the past 30-40 years. These include the fragile papershell, Leptodea fragilis, the giant floater, Anodonta grandis, and the pink papershell, Potamilus ohiensis. As mentioned in the section on commercial harvest, the greatest threat to the native Illinois mussel fauna may be the impact caused by the introduction of the zebra Co 1963 mmm 1992 Water Column 70 Fishes 100 1092 Sediment Contact Fishes Fish with External Abnormalities (%) Lower Middle Upper Mississippi River Chicago Illinois Waterway Section Figure 38. Incidence of externally visible abnormalities (sores, eroded fins, lumps) on fishes that mainly inhabit the water column (top figure) and on fishes that are likely to come into frequent contact with bottom sediments (bottom figure) for 1963 and 1992 in three sections of the Illinois Waterway. Numbers above each bar represent the total number of individuals caught for that river segment. Overall, for both years, the incidence of external abnormalities was higher on sediment-contact fishes than on water-column fishes, indicating irritating substances may be present in the sediments. The incidence of external abnormalities on sediment-contact fishes in both 1963 and 1992 and on water-column fishes in 1963 increased toward the Chicago area, implicating this area as the source of the factor or factors causing the abnormalities. Percentages were much lower in 1992 than in 1963, pratically disappearing in water-column fishes, indiating some reduction in the source. FLOWING WATERS ____ mussel, Dreissena polymorpha, to the streams of Illinois. Another introduced species, the Asian clam, Corbicula fluminea, has been found throughout the state, although less frequently in the northern third. The effect of Corbicula on the native fauna is not well understood and is often debated. Aquatic Insects With the exception of mussels and clams, there has been very little recent attention paid on a statewide basis to the status of invertebrate communities in the streams and rivers of Illinois. Small isolated studies scattered in time and space cannot be effectively used to derive meaningful trends in the status of lotic invertebrates in Illinois. Given the extensive modifica- tion and/or degradation of stream habitats that has occurred over the past 30 years, we might expect trends among stream invertebrates similar to those of other aquatic groups; however, the relative sensitivities of these aquatic groups to various types of environmental modification can vary greatly. The inability to discuss the current status of inverte- brate populations in Illinois is unfortunate for at least two primary reasons. The first is that benthic inverte- brates are generally excellent indicators of environmen- tal quality because they have low vagility as larvae and generally exhibit quick responses to environmental change. (In comparison, fish have generally high vagility, and many are long-lived, so that it may take many years for the effects of environmental change to be obvious in fish communities). The second reason for regretting the paucity of information on the current status of stream invertebrate communities is that Illinois is unique nationally in having excellent historical data on aquatic insect distribution dating as far back as the 1860s. The comprehensive treatments of the Illinois fauna published by T.H. Frison (The Stoneflies, or Plecoptera, of Illinois. Illinois Natural History Survey Bulletin 20[4], 1935), H.H. Ross (The Caddis Flies, or Trichoptera of Illinois. Illinois Natural History Survey Bulletin 23[1], 1944), and B.D. Burks (The Mayflies, or Ephemeroptera of Illinois. Illinois Natural History Survey Bulletin 26[{1], 1953) were landmark publications in their day and provide detailed accounts of where and when particular species were collected as well as some limited qualitative assess- ments of their abundance in streams throughout Illinois. These accounts, when taken together, give us a picture of conditions in Illinois streams during the 1920s, 1930s, and 1940s and provide an invaluable baseline from which changes to stream environments since that time can be assessed. These changes are 207 —_______ FLOWING WATERS North Shore ]~* Channel Chicago Metropolitan Area Des Plaines Sample site Sewage treatment outfall Direction of flow Lock Des Plaines River Calumet Saginaw Channe/ Chicago River Litte Calumet River Sanitary and Ship Canal Mississippi weet CA) a Chance, i. Little: AX Grand Calumet RiverCalumet River Sangamon River Wabash River Missouri River IR = Minoks River : c Sie wouis MR = Mississippi River 2 @ = Sampk site 3 /__= Lock and dam = 7) Ohio River (= 2 Mississippi 2 River £ 7° MR377——IR6_ __—«IR124__—‘IR215_ DP277 DP286_ SS310_SS316_CA325 CS308 Pool 19 JR72,—«IR180 =—1R248 ~DP281 SS292 SS313 SS318 CR326 10318 River Mile River River | Chicago Metropolitan Area Miss. Illinois Figure 39. Response of fingernail clams to sediments collected in 1990 from the Upper Mississippi River, Illinois River, Des Plaines River, and Chicago waterways. Negative responses indicate toxicity and positive responses indicate stimulation. All the sediments from the Illinois River and Upper Mississippi River were nontoxic in these short-term tests (1 hour of exposure), whereas all the sediments from the Chicago area were acutely toxic, except for one sample from the Sanitary and Ship Canal at mile 316. More sensitive tests with fingernail clams have demonstrated toxicity even in sediments from the middle section of the Illinois Waterway (Sparks et al. 1981). The toxicity is largely attribuiable to un-ionized ammonia, with some contribution from petroleum hydrocarbons (Sparks et al. 1992). The fingernail clam was an important food organism for bottom-feeding fish and diving ducks in the middle and lower Illinois Waterway until it died out in the 1950s (Sparks 1984). As a result, the condition of bottom- feeding fish declined and diving ducks virtually ceased using the middle and lower waterway (Sparks 1984). The toxicity test measures how rapidly the clams remove food particles from water, following 1 hour of exposure to water extracted from the sediment samples. Reduction of feeding ultimately caused starvation and death of the clam. The horizontal dashed lines indicate significant response thresholds for inhibition or stimulation of feeding: 2 X the standard deviation + the mean difference in feeding rates determined in 18 control trials with no exposure to toxicants (Sparks et al. 1992). 208 Table 9. Mean relative weight (W _) for bluegill and carp for 1963, 1975, and 1991.* Bluegill Carp Year ~ N Mean W N Mean W 1963 50 0.914 995 0.877 1975 123 0.984 449 0.781 1991 347 1.06 114 0.795 * W_ is determined by dividing an individual fish’s weight by a length-specific standard weight (W.), where W. represents the top quartile of fish from a specific region (Murphy et al. 1991). A W, equal to or greater than 1.0 indicates a healthy fish and, therefore, favorable ecological conditions, while a W, less than 1.0 may indicate a food supply problem or some other factor (pollution stress) which is unhealthful to fish. Bluegill, which mainly inhabit the water column rather than foraging on the bottom, had a mean W, close to 1.0 for 1963, 1975, and 1991, indicating that food supply may not be a problem for these species. In contrast, mean W.’s for carp, a bottom-feeding omnivore, were consistently less than 1.0 for all three years, indicating their environment may be less than conducive to healthy growth or that the food supply is limited in quantity or quality. Sparks (1984) and Starrett (1971) related the poor condition of bottom-feeding fishes to the lack of invertebrates (fingernail clams, aquatic worms and insects) on the bottom of the river. The lack of invertebrates is in turn linked to the occurrence of toxic levels of ammonia in the sediments (see Figure 38). likely complex and will include both degradation (due to channelization, siltation, etc.) and improvement (due to increased treatment and control of human and indus- trial wastes) in stream environments since the 1940s. It is virtually certain that many of the species reported by Frison, Ross, and Burks have been extirpated from areas where they formerly occurred; however, the extent to which this has occurred is unknown. For example, the unusual Pecatonica River mayfly (Acanthometropus pecatonica), listed as a candidate for protection under the Endangered Species Act, was originally collected in the Sugar and Pecatonica rivers in the 1920s but has not been seen there since and may well be extirpated from Illinois because of extensive channelization and degradation of small rivers. However, the status of the Pecatonica River mayfly and of many other potentially endangered stream inverte- brates remains unknown. Currently, Illinois lists only one species of stream insect as endangered, although at least 11 federally listed species are known to have once occurred in Illinois. Many other stream species listed as state endangered or threatened in Wisconsin and other FLOWING WATERS neighboring states also remain unlisted in Illinois, with their status here totally unknown. Crayfishes Data from a 10-year survey (Page 1985) of 1300 Illinois localities and historical information indicate that 23 crayfishes have been found at one time or another to be reproducing in the state. One species, Cambarus robustus, has disappeared during this century (Table 12), and two species, Orconectes rusticus and Orconectes menae, have been introduced. Cambarus robustus was recorded from Illinois (Table 12) at the turn of the century but has not been found in the state since then. In the northeastern United States, it is found in cool rocky streams, and its presence in Illinois at the turn of the century may have represented relict populations left over from a more widespread distribution in a cooler postglacial climate. Its disap- pearance may have represented natural extinction in Illinois. However, other Illinois crayfishes are seriously threatened with extirpation (Table 12) as a result of the same factors negatively affecting fishes and other stream organisms: excessive siltation associated with agricultural practices; the drainage of bottomland lakes; water pollution; stream desiccation that follows the lowering of the water table as groundwater is removed for agriculture and municipalities; competi- tion and predation by introduced species; and dams that convert streams into standing water. Orconectes rusticus was first found in Illinois in 1973 and is rapidly expanding its range. Orconectes menae was first found in Illinois in 1992 and appears to be restricted to one stream in Greene County. Both species are used as fishing bait and probably were introduced into streams by fishermen. O. rusticus occurs naturally in northern Kentucky and southern Indiana. It has been introduced throughout much of northeastern United States and now is reproducing in almost all the states north of the Ohio River and east of the Mississippi as well as in Iowa, Missouri, and New Mexico. Until recently, O. rusticus was sold at bait shops in northern Illinois; however, possession of live O. rusticus is now illegal in Illinois. O. menae, native to southwestern Arkansas and eastern Oklahoma, probably was released in Illinois by a single fishermen. Aquatic Vascular Plants Aquatic macrophytes are an integral part of rivers and lakes. They diversify habitats for fish and fuel second- FLOWING WATERS Table 10. Illinois amphibians inhabiting lotic environments. Species Salamanders Cryptobranchus alleganiensis Notophthalmus viridescens Ambystoma texanum Desmognathus conanti Eurycea cirrigera Eurycea longicauda Eurycea lucifuga Common Name Hellbender Newt Smallmouth salamander Dusky salamander Two-lined salamander Longtail salamander Cave salamander Four-toed salamander Hemidactylium scutatum Necturus maculosus Siren intermedia Mudpuppy Lesser siren Frogs Acris crepitans Cricket frog Rana blairi Plains leopard frog Rana catesbeiana Bullfrog Rana clamitans Green frog Rana palustris Rana pipiens Rana utricularia Pickerel frog Northern leopard frog Southern leopard frog Habitat* Status P Watch list PS Greatly reduced | eeopal b> Widespread 15 0S State endangered Hes Locally common He's Locally common H Locally common 16 by Be Watch list P Uncommon P Locally abundant SBS Locally abundant PS Uncommon S, PS Common S Common H, PS Uncommon S, PS Locally common S, PS Common * H = headwaters, spring-fed streams, or caves; S = streamside; L = only during larval stage; PS = ponded streams, ponds, and marshes; P = permanently aquatic adults. All have an aquatic larval stage that may be found in lotic waters. ary production by producing organic matter, cycling nutrients, and providing cover for fishes and substrate for fish food organisms. Since human settlement, there has been a decline in aquatic macrophytes in riverine systems. This section describes changes in aquatic macrophyte populations in three large rivers. Illinois and Mississippi Rivers. Aquatic vegetation in large floodplain-river ecosystems is very dynamic and closely linked to the hydrology and water quality of the river. Through the 20th century, aquatic vegetation was observed to decline throughout the Illinois River ecosystem. Pollution, intensive agriculture, and navigation lead to poor water quality and high rates of sedimentation and sediment resuspension that limits light penetration necessary for growth and establish- ment of aquatic plant beds. High rates of sedimentation and artificially high water levels, necessary for modern river navigation, also result in sediment deposition in backwater lakes, creating flocculent sediments in which plants have difficulty rooting. Some signs of recovery are reported by staff at the Illinois Natural History Survey’s Long Term Resource Monitoring Program (LTRMP) Field Station at the LaGrange Pool 210 of the Illinois River. They have found submersed aquatic plants appearing in areas where they have not been found for many years. Aquatic plants in the Mississippi River follow a north- south gradient, with aquatic plants being more diverse and more numerous in the north. Relatively low rates of sedimentation in the upper reaches of the river provide conditions favorable to the development of aquatic plants. Increased rates of sedimentation from Illinois and Iowa farms reduce light penetration through the water and subsequently reduce the amount of aquatic plants found in the southern parts of the river. Monitoring of aquatic vegetation at the Illinois Natural History Survey’s LTRMP Field Station at Pool 26 of the Mississippi River has provided data necessary to evaluate some of the mechanisms controlling aquatic vegetation distribution in the upper river. Submersed aquatic vegetation was abundant in some portions of Pool 26 in 1989 (Figure 41). Stable water levels (Figure 42) and reduced sediment input, resulting from a two-year drought, created conditions favorable to the Table 11. Illinois reptiles inhabiting lotic environments. Species r Turtles Chelydra serpentina Macroclemys temmincki Kinosternon flavescens Kinosternon subrubrum Sternotherus odoratus Chrysemys picta Clemmys guttata Emydoidea blandingi Graptemys geographica Graptemys pseudogeographica Pseudemys concinna Trachemys scripta Apalone mutica Apalone spinifera Snakes Clonophis kirtlandii Farancia abacura Nerodia cyclopion Nerodia erythrogaster Nerodia fasciata Nerodia rhombifer Nerodia sipedon Regina grahami Regina septemvittata Thamnophis proximus Thamnophis sauritus Agkistrodon piscivorous FLOWING WATERS Common Name Habitat* Status Common snapping turtle Cc Common Alligator snapping turtle Cc Watch list Illinois mud turtle A Endangered Eastern mud turtle A Rare Common musk turtle Cc Common Painted turtle A Common Spotted turtle A Endangered Blanding’s turtle A Watch list Common Map turtle c Uncommon False map turtle 6: Locally common River cooter Cc Endangered Slider A Abundant Smooth softshell Cc Watch list Spiny softshell C Common Kirtland’s snake A Watch list Mud snake A Uncommon Mississippi green water snake A Threatened Plainbelly water snake A Locally common Broad-banded water snake A Endangered Diamondback water snake A Locally common Northern water snake A Common Graham’s water snake A Uncommon Queen snake A Uncommon Western ribbon snake A Common Eastern garter snake A Endangered Cottonmouth A Locally common * C = adults completely aquatic except for egg laying, hibernation, and dispersal), A = amphibious, moving in and out of water. development of submersed aquatic plant beds. When typical water levels (Figure 43) and runoff rates returned, those beds disappeared (Figure 44). The degree of change is summarized in Figure 45. Similar changes were reported by the LTRMP Field Station at Pool 13 (Michael Griffin, lowa Department of Natural Resources, personal communication). The major differences between the two locations is that Pool 13 has extensive aquatic vegetation beds in most years whereas Pool 26 has extensive vegetation beds only during drought years. The LTRMP Field Station in the unimpounded portion of the river, near Cape Girardeau, Missouri, has never documented aquatic plants in that portion of the River (Yao Yin, Missouri Department of Conservation, personal communication). Des Plaines River. To assess the extent and track the changes in aquatic macrophyte coverage in the Des Plaines River (river miles 273-286; see Figure 46), aerial photographs and ground truth surveys were carried out annually from 1985 to 1991 (Tazik and Sobaski 1992) About 65% of the total 693 ha of water surface area, or 450 ha, is potentially habitable by submersed and emersed vegetation. Vegetation coverage in this reach has fluctuated dramatically over the past seven years (Figure 47). During earlier surveys 10-13% of the 450 ha was vegetated; in 1991 the vegetated areas constituted 6% of the potentially habitable areas. Peak vegetation levels (60 ha) were reached in 1987, and since then there has been a steady decline to the estimated 27.5 ha in 1991 (Figure 47). FLOWING WATERS Total Fauna HE 1950s No. of Species EmbarrasR Little Wabash R. Sangamon R. Kaskaskia R. HB 1950s HH 1980s No. of Individuals Embarras R. Little Wabash R. Sangamon R. Kaskaskia R. Figure 40. (A) Number of mussel species known to have occurred in four rivers in Illinois and the number of species present in the 1950s and the 1980s. (B) Abundances of mussels in the 1950s and 1980s in the Embarras, Little Wabash, Sangamon, and Kaskaskia rivers. Concomitant with this decrease in vegetation cover has been a shift in relative importance of heavily vegetated areas within the reach (Figure 48). The most dramatic decrease has occurred in the area just upstream of the confluence of the Des Plaines and Kankakee rivers (Segment 6) (Figure 48), where in 1985-1987 there was an average of 8.85 ha of vegetation, and in 1991 there was less than 1 ha. In addition to an overall drop in coverage, there has been a dramatic shift in the species composition. This shift in species composition in Segment 6 has resulted in Myriophyllum spicatum becoming a more important part of the community dominating several areas of the reach (Tazik and Sobaski 1992). There has been a decrease in Potamogeton crispus, P. nodosus, P. pectinatus, and Vallisneria americana. Emersed vegetation species composition has remained relatively stable with Typha spp. and Sagittaria latifolia remain- ing dominant (Tazik and Sobaski 1992). Most probable explanations for the declines in cover- age and shifts in species composition are the physical factors of the reach and the 1988 drought and carryover conditions (Figures 47 and 48). Although results of chemical analyses indicate that, in general, there have 212 Table 12. Extirpated and endangered species of native Illinois crayfishes and their former or present distribu- tion. Species Distribution Extirpated Cambarus robustus Quincy (Adams Co.), Decatur (Macon Co.) Endangered Orconectes indianensis Orconectes kentuckiensis Orconectes lancifer Orconectes placidus Southeastern Illinois Southeastern Illinois Southern Illinois Southern Illinois not been substantial changes between 1987 and 1991 in element levels in sediments, and probably not in macrophyte tissues, there are significant differences in the toxicity of sediments between sampling sites (Tazik and Sobaski 1992). Furthermore, although there has been a significant decline in the concentrations of barium, copper, and mercury, the sediments throughout this reach are subject to considerable pollution and have had notably toxic sediments. RESTORATION AND PROTECTION This section catalogues stream habitat management projects on streams other than the Mississippi and Illinois rivers. Stream habitat management projects can be divided into four categories, starting with protection projects, which seek to protect existing habitat from degradation. Restoration projects are aimed at restoring aquatic habitat by reversing degradation. Habitat enhancement efforts are meant to improve habitat, usually for one or two species of sport fish. The objective of an erosion control project is to stabilize a stream channel. Stream management projects usually include elements of more than one of these categories; for example, a restoration project may be aimed at erosion control. Although stream restoration projects are usually thought of as physical manipulations of streams, they can be passive as well; that is, destructive forces can be removed and streams allowed to heal with time. Figure 49 shows current stream habitat management projects in Illinois. A designated 17-mile section of the Middle Fork of the Vermilion River is Illinois’ only federally designated National Wild and Scenic River. FLOWING WATERS Landcover/Use [] Open Water feat Submergents ig, Aquatics = Rooted/Floatin ig RK Submergent/Rooted Floatin fl) Emergents Be MEIERS Grasses/Forbs al py Woody Terrestri 3000 SS Agriculture Urban/Developed Figure 41. Land cover/use at Pool 26 of the Mississippi River in 1989. _______ FLOWING WATERS 134 DENN (site dry at 127.2m] 133. | 132 4 131 L 130 L 129 | 128 - a eee 127 126 L 125 L — ~ JAN MAR MAY JUL SEP NOV FEB APR JUN AUG OcT DEC Date Figure 42. Hydrograph (stage height) of the Mississippi River at Alton, Pool 26, in 1989. This section is also a designated State Protected River (Illinois Department of Conservation 1992). The Illinois Nature Preserves Commission has established nature preserves on the Littlé Vermilion and Cache rivers. Figure 49 also shows structural habitat manage- ment projects in Illinois. These are primarily aimed at erosion control but include fish habitat enhancement elements. Stream habitat management of this kind is relatively new in the state. The oldest of these projects, on Crow Creek, was initiated in 1986. All of these projects were initiated by Donald Roseboom (Illinois State Water Survey), and most involved cooperation with the Illinois Department of Conservation. Struc- tures used in these projects include “lunkers,” which are wooden, rock-covered devices used to prevent bank erosion and provide overhead cover for fish (Roseboom et al. 1992), and tree revetments, which are rows of trees anchored along streambanks to prevent erosion and encourage the growth of riparian vegeta- tion. Live booms are rock and soil jetties in which willow cuttings are placed. Willow posts are large willow cuttings (about 12 feet long) that are planted upright in stream banks. The root systems of these plantings help stabilize streambanks, and their stems, branches, and leaves protect banks and provide food and cover for terrestrial and aquatic wildlife. A-Jacks are prefabricated concrete structures that resemble the toys of the same name and are used in conjunction with willow cuttings to stabilize eroding streambanks (Donald Roseboom, personal communication). 214 1991 (site dry at 126.8m 133 132 £ #31) - 130 | 129 | 128 L re ni RO En WI 127 L 126 L 125 yf T | | T | a | B T JAN MAR MAY JUL SEP nov ! FEB APR JUN AUG DEC Date Figure 43. Hydrograph (stage height) of the Mississippi River at Alton, Pool 26, in 1991. Many, if not most, Illinois streams are markedly degraded from their presettlement condition. As past management of these streams is reevaluated, the demand for restoration knowledge is increasing. As an example, ditching, channelization, and devegetation of streams for flood control is now understood to have been only partially effective in some watersheds and ineffective in others. The legacies of this management can in many cases be corrected by restoration. Current research is limited in scope (e.g., Roseboom et al. 1992) and is only a first step in meeting the needs for restoration knowledge in Illinois. Pressing questions center on multiobjective management and concern, for example, the effects of channelization on stream ecosystems and how streams might be better managed for aquatic habitat without limiting their effectiveness in conveying floodwaters. The historical conditions of Illinois streams are poorly understood, although such information is necessary to know to what condition they should be restored. Finally, restoration methodol- ogy suitable for the unique zoogeographic and physi- ographic regions of Illinois must be further developed and tested. SUMMARY AND RECOMMENDATIONS The biodiversity of Illinois’ flowing waters has been markedly altered during the 20th century. Substantial numbers of fish, amphibian and reptiles, and inverte- FLOWING WATERS Landcover/Use a Submergents = Rooted/Floating Aquatics ating a Submergent/Rooted Flo a Emergents 1000 2000 3000 0 2 Grasses/Forbs 77) v e § * 2 3 6 8 Ss =a Z| Figure 44. Land cover/use at Pool 26 of the Mississippi River in 1991. Z Urban/Developed wy NN Area (hectares) FLOWING WATERS [1989 Wi1991] BO 60 oUt Terrestrial Submergent Rooted Floating Emmergent Figure 45. Coverage by aquatic (submerged, rooted / floating, emergent) and terrestrial vegetation at Pool 26 of the Mississippi River at Alton in 1989 and 199]. brate species that inhabit running waters have been extirpated in Illinois since 1900. Thirteen species of fish (7% of the fauna present at the start of the century) no longer exist in Illinois, while an additional 23 species (12.3% of the fauna present in 1900) are listed as threatened or endangered and are in danger of being extirpated. Fewer amphibians or reptiles have been extirpated in Illinois (only 1 of 44 flowing-water species), but about 33% of the remaining species are at great risk of being lost because of declining popula- tions. By far the worst situation known is for the freshwater mussels; 15 species (19% of the “original” fauna) are now extinct in Illinois while an additional 28 species (44% of the current fauna) are considered to be at considerable risk of extinction in Illinois. Therefore, over half (55%) of Illinois’ mussel species either are no longer present in Illinois or are in danger of being eliminated from the state. Finally, nearly 22% of Illinois’ crayfishes either no longer exist in Illinois or are endangered. Unfortunately, similar information is not available for other groups of organisms that inhabit flowing waters. This is especially troublesome for two groups—aquatic insects and plants (algae and macrophytes)—that are functionally extremely important in stream ecosystems. 216 Recent evaluations of the biotic integrity (or health) of Illinois’ streams and several long-term studies suggest that it should not be surprising that such a high proportion of its flowing-water fauna should either be extinct or in danger of extinction in Illinois. Using biological criteria to assess the condition of streams shows that the proportion of stream miles in Illinois of moderate to very poor quality greatly exceeds the proportion rated as good to excellent. Unfortunately, similar earlier statewide evaluations of the quality of Illinois’ streams were not performed. Nonetheless, earlier workers (e.g., Ross [1944]) who sampled extensively throughout the state lamented about the overall quality of streams in Illinois and noted that a very high proportion of the streams had been apprecia- bly manipulated. Interestingly, Ross (1944) did not refer to effects of urbanization, especially the effects of organic effluents such as sewage, as being major causes of poor stream quality. Rather, he considered landscape manipulations within watersheds (e.g., removal of riparian vegetation, agricultural practices leading to increased erosion from farmlands, channelization of streams) to be the major factors affecting stream quality. Unfortunately, we do not have data on long-term trends in many land use practices within watersheds and are, therefore, unable to associ- ate such trends with current assessments of stream quality. Despite Ross’ (1944) comments, discharge of sewage effluents into streams strongly affected stream quality, especially in the first 60-70 years of this century. Two long-term studies of fish populations (Illinois River; streams in Champaign County) have documented improvements in stream quality (based on the status of fish populations) over the past 30 years that are likely the result of improved treatment of sewage discharged into streams. Especially noteworthy are marked improvements in functionally and economically important piscivorous populations (e.g., smallmouth and largemouth bass, channel catfish) in both studies. Nonetheless, the current status of fish populations in both systems indicates that significant problems persist. In the upper Illinois River, bottom-dwelling fishes have poor body condition and a high incidence of external abnormalities, suggesting a continuing problem with sediments, which are known to be toxic to the inverte- brates on which these bottom-dwelling fishes feed. In Champaign County, the frequency with which species that are tolerant of poor habitat quality are encountered has increased over the past 90 years. Similar improvements have not been noted for mussel populations from four rivers in east-central Illinois for DES PLAINES RIVER MILES —=EE——— Segment 3 Treats leland Segment 4 FLOWING WATERS eZ AK Segment 1 i Segment 2 Cee Sal Segment 5 Ci Wit Cao. Forest Preserve sland y, Dy Sapanad ((/ ’ /} Segment 6 Figure 46. The Des Plaines River study reach including river miles 273 through 286 in Will and Grundy counties, Illinois. _____. FLOWING WATERS go —2— COVERAGE (HA) Aquatic macrophyte vegetation coverage (ha) 1984 1986 1986 1990 1992 YEAR Figure 47. Vegetation cover in the lower Des Plaines River (river miles 273-286) during the past seven years. About 65% of the total 693 ha of water surface area, or 450 ha, is potentially habitable by submersed and emersed vegetation. This includes main channel border, slough, and side channel areas but excludes the main navigation channel. During earlier surveys 10-13% of the 450 ha was vegetated; in 199] the vegetated areas constituted 6% of the potentially habitable areas. Peak vegetation levels (60 ha) were reached in 1987, and since then there has been a steady decline to the estimated 27.5 ha in 1991. The above graph demonstrates the significant decline in total vegetation cover in the lower Des Plaines River from 1985 to 1991. There are a number of hypotheses to explain the decrease in plant populations in the study reach, most relating to physical factors. The drought of 1988, and carryover of those conditions to a lesser degree in 1989, may explain some of the decline in coverage. Decreased water depths both during the drought and afterward, resulting from increased sediment deposition due to poor watershed manage- ment, may account for some of the most significant decreases in vegetation cover. With decreases in water depth it is likely that much of this area became too shallow to support submersed vegetation. Drought conditions in 1988 may have caused barge traffic to increase. Low water levels may have necessitated an increase in the total number of barges handling smaller individual tows to avoid running aground with more traditional larger tows. Under this scenario, the frequency of disturbance would increase although the magnitude would decrease, which may affect aquatic vegatation more severely. 218 Aquatic macrophyte vegetation coverage (ha) O=NHENANDO Figure 48. Changes in vegetation cover in various segments of the lower Des Plaines River, 1985 to 1991. The most dramatic decrease occurred in the area just upstream of the confluence of the Des Plaines and Kankakee rivers (segment 6), where in 1985—1987 there was an average of 8.85 ha of vegetation, and in 199] there was less than I ha (see Figure 46). Total vegetation cover in segment 1 (Brandon Road) fluctu- ated between 4.3 and 13 ha during the monitoring period; the nearly 8 ha present in 199] represented an increase over the 4-5 ha documented in 1988-1990. Vegetation in segment 4, the side channel near Treats Island, has decreased consistently sonce 1985. Signifi- cant differences in sediment toxicity of these sampling sites have been found but do not account for the site variability in vegetation cover. Again, the physical differences of the segments and the impact of the 1988 drought are more likely the cause for the differences in vegetation cover in each of the segments. Results of chemical analysis indicate that, in general, there have not been substantial changes between 1987 and 199] in element levels in sediments, and probably not in macrophyte tissues, although sample size was limited. Furthermore, although there has been a significant decline in the concentrations of barium, copper, and mercury, the sediments throughout this reach are subject to considerable pollution and have had notably toxic sediments. Figure 49. Restoration and protection of rivers and streams in Illinois, excepting the Mississippi and Illinois rivers, and methods used. (1) Waukegan River, lunkers and A-jacks (see text for description of struc- tures); (2) Glen Crest Stream, lunkers and A-jacks; (3) Franklin Creek, lunkers and tree revetment; (4) Court Creek, will posts and lunkers; (5) Crow Creek, live booms with willow facines and willow posts; (6) Sanachwine Creek, willow posts; (7) Richland Creek, willow posts; (8) Middle Fork of the Vermillion River, National Wild and Scenic River System and State Protected River, protection only; (9) Little Vermillion River, Illinois Nature Preserve; (10) Cache River, Lower Cache River State Natural Area. FLOWING WATERS which there are long-term records. In all four rivers, large reductions in populations of most mussel species have occurred over the past 40 years, apparently due to increased siltation and loss of suitable habitat. Mussel populations in Illinois’ largest rivers, the Mississippi and the Illinois, face similar threats and also must contend with exploitation by humans for the cultured pearl industry. Commercial harvest of mussels in these rivers increased dramatically between 1987 and 1990. Without fundamental information on vital rates for harvested populations, it is unclear whether these populations can sustain such high rates of exploitation. Similarly, it is unclear whether commer- cially harvested fish populations in the Mississippi, Illinois, Kaskaskia, and Wabash rivers are being overexploited. Mussel populations may also be affected by exotic species, such as the zebra mussel and the Asiatic clam. Similar problems face other invertebrates (e.g., crayfish), fish, and macrophytes. Perhaps more important than their effects on individual species populations, exotic species can also markedly affect ecosystem structure and function. Little information exists for any of these in Illinois. Numerous areas requiring additional research are evident from the preceding discussion. The following general areas are in particular need of immediate attention: * Considerably more data are needed on the population dynamics of harvested species so that allowable harvest rates can be better determined. ¢ Research on the anticipated effects of exotic species on species populations and on ecosystem-level proper- ties is needed to develop management plans. * Long-term studies need to be established on func- tionally significant groups in lotic systems (e.g., aquatic insects, crayfish, plants) for which little long- term data exist. Long-term studies on other populations (e.g., fish, mussels) need to be expended to include a broader range of systems represented in Illinois. * Much more research on the ecology of large rivers is greatly needed. Considerably less is known about the mechanisms affecting the structure and function of such systems relative to smaller streams. In particular, the effects of manipulations within the floodplain (e.g., levee construction) and within the stream channel (e.g., navigation dams, navigation traffic) need further 219 —_____. FLOWING WATERS attention. An experimental approach, although difficult to take on such large systems, would be advisable in many circumstances. For example, destruction of levees on several large rivers by the Great Flood of 1993 provides a unique opportunity to experimentally address the effects of such structures on population-, community-, and ecosystem-level properties. Appropri- ate agencies should consider appropriating funds for such research immediately. Restoration, protection, and management of Illinois’ streams requires the adoption of a large-scale perspec- tive (i.e., watershed-level or basin-level) regarding the structure and function of stream ecosystems. Stream reaches tend to be managed as though they were independent of upstream or downstream reaches within the watershed or drainage basin. This practice ignores virtually everything that is known about how stream ecosystems work. Any given segment of stream is strongly influenced by things occurring within the segment and by things occurring upstream of the segment in the watershed and downstream (e.g., from damming). Few perturbations to streams can be considered to be processed locally, within a stream segment (e.g., sewage effluents), and, consequently, to have little influence on downstream segments. Most other perturbations that appear to be markedly affecting Illinois streams (e.g., land-use practices affecting stream morphology, sedimentation, inputs of polluting chemicals such as plant nutrients, herbicides, pesti- cides, and other toxic chemicals) cannot be considered to be “processed” within a given stream segment, in part because the inputs (of sediments, chemicals) generally are not localized and because many perturba- tions (e.g., inputs of sediments) are more or less bio- logically inert and, therefore, are not “processed” at all. Similar to this expanded longitudinal perspective is that, in larger streams, an expanded lateral perspective should also be adopted. Larger streams are intimately connected in terms of morphology, hydrology, struc- ture, and function with their floodplains as well as with upstream reaches within the drainage basin. Manage- ment of large rivers in Illinois and elsewhere has expressly attempted to uncouple this link between the river and its floodplain, largely through the construc- tion of levees and dams. The consequences of such attempts can be disastrous for humans (e.g., the Great Flood of 1993) as well as for the biota of large rivers, although more research in this area is urgently needed. The bottom line is that, for example, management of a larger stream must consider what is occurring through- out the drainage basin, especially upstream of the area of interest and immediately downstream, and laterally within the floodplain. Therefore, management of large streams requires management of their tributaries throughout the drainage basin. Adoption of such a perspective will not be easy. For example, the struc- ture, function, and utilization of drainage districts will have to be dramatically altered. However, only through the adoption of such a perspective will we be able to improve stream quality and preserve and protect existing high-quality streams in Illinois. LITERATURE CITED Arner, D.H., H.R. Robinette, J.E. Frasier, and M.H. Gray. 1976. Effects of channelization of the Luxapalila River on fish, aquatic invertebrates, water quality and furbearers. U.S. Fish and Wildlife Service. U.S. Department of the Interior Biological Services Program Report No. FWS/ OBS-76/08. Baker, F.C. 1928. The fresh-water mollusca of Wiscon- sin. Part II. Pelecypoda. Wisconsin Geological and Natural History Survey Bulletin 70. 495 p. Baur, R.J. 1991. 1989 Illinois sport fishing survey. Special Fisheries Report Number 54, Office of Resources and Management, Division of Fisheries, Illinois Department of Conservation, Springfield. 52 p. Baxter, R.M. 1977. Environmental effects of dams and impoundments. Annual Review of Ecology and Systematics 8:255-283. Bayley, P.B. 1991. The flood pulse advantage and the restoration of river-floodplain systems. Regulated Rivers: Research and Management 6:75-86. Bayley, P.B., and D.C. Dowling. 1990. Gear efficiency calibrations for stream and river sampling. Aquatic Ecology Technical Report 90/8. Illinois Natural History Survey, Champaign. 51 p. Bayley, P.B., R.W Larimore, and D.C. Dowling. 1989. Electric seine as a fish-sampling gear in streams. Transactions of the American Fisheries Society 118:447-453. Buck, D.H. 1956. Effects of turbidity on fish and fishing. Oklahoma Fisheries Research Laboratory. Report No. 56. Norman, Oklahoma. Burks, B.D. 1953. The mayflies, or Ephemeroptera, of Illinois. Illinois Natural History Survey Bulletin 26: 1-216. Burr, B.M. 1991. Fishes of Illinois: an overview of a dynamic fauna. Pages 417-427 in L.M. Page and MLR. Jeffords, eds. Our living heritage: the biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4). Cagle, F.R. 1941. A key to the reptiles and amphibians of Illinois. Museum of Natural and Social Sci- ences, Southern Illinois University, Carbondale. iv + 32 p. Coker, R.E. 1919. Fresh-water mussels and mussel industries of the United States. Bulletin of the Bureau of Fisheries 36:13-89. Conlin, M. 1991. Illinois River fisheries and wildlife resources. Pages 28-36 in H. Korab, ed. Proceed- ings of the 1991 Governor’s Conference on the Management of the Illinois River System. Third Biennial Conference, October 22—23, Peoria, Illinois. Davidson, B.M. 1924. Seventh annual report of the Department of Agriculture. State of Illinois. p. 22-24. Davis, N.S., Jr. and F.L. Rice. 1883. List of batrichia and reptilia of Illinois. Chicago Academy of Science Bulletin 1:25-32. Essig, H.W. 1991. Chemical and biological monitoring of the upper Illinois River. Pages 68-77 in H. Korab, ed. Proceedings of the 1991 Governor’s Conference on the Management of the Illinois River System. Third Biennial Conference, October 22-23, Peoria, Illinois. Forbes, S.A. and R.E. Richardson. 1908. The fishes of Illinois. Illinois State Laboratory of Natural History, Urbana. cxxxi + 357 p. plus separate atlas containing 103 maps. Frison, T.H. 1935. The stoneflies, or plecoptera, of Illinois. Illinois Natural History Survey Bulletin 20(4):28 1-471. Fritz, A.W. 1990. A strategic plan for the management of the freshwater mussel resources of the Upper Mississippi River. Upper Mississippi River Conservation Committee, Rock Island, Illinois. 17 p. Garman, H. 1892. A synopsis of the reptiles and amphibians of Illinois. Illinois Laboratory of Natural History Bulletin 3(13):215—388 + [8]. Gaugush, R.F. 1993. Kriging and cokriging applied to water quality studies. U.S. Fish and Wildlife Service, Environmental Management Technical Center, Onalaska, WI. Reprint No. 93-R027. 18 p. Gaugush, R.F. 1992. Recent trends in water quality of the Illinois and Upper Mississippi rivers. Page 20 in Proceedings of the Mississippi River Research Consortium, Inc. Volume 24. 76 p. Gilbertson, D.E., and T.J. Kelly. 1981. Summary resource description Upper Mississippi River FLOWING WATERS System. Upper Mississippi River Basin Commis- sion. Biology Volume 4. 102 p. Gregory, S.V., F.J. Swanson, W.A. McKee, and K.W. Cummins. 1991. An ecosystem perspective of riparian zones. BioScience 41:540-551. Henegar, D.L., and K.W. Harmon. 1973. A review ofreferences to channelization and its environmen- tal impact. Pages 79-83 in E. Schneberger and J.L. Funk, eds. Stream channelization: a symposium. North Central Division of the American Fisheries Society, Special Publication No. 2. Hite, R.L. and B.A. Bertrand. 1989. Biological stream haracterization (BSC): a biological assessment of Illinois stream quality. Illinois State Water Plan Task Force Special Report 13, Illinois Environ- mental Protection Agency, Springfield. Hortle, K.G., and P.S. Lake. 1982. Macroinvertebrate assemblages in channelized and unchannelized sections of the Bunyip River, Victoria. Australian Journal of Marine and Freshwater Research 33:1071-1082. Hunter, R. D., and J. F. Bailey. 1992. Dreissena polymorpha (zebra mussel): Colonization of soft substrata and some effects on unionid bivalves. The Nautilus 106(2):60—67. Hynes, H.B.N. 1970. The ecology of running waters. University of Toronto Press. 555 p. Hynes, H.B.N. 1975. The stream and its valley. Verhandlungen Internationale Vereinigung fur Thoeretische und Angewandte Limnologie 19:1—15. Illinois Department of Conservation. 1992. Corridor management plan for the middle fork of the Vermilion River, state andnational scenic river. Illinois Department of Conservation,Springfield. April 1992. . 1993. 1993 fishing information. Illinois Department of Conservation, Springfield. Illinois Environmental Protection Agency. 1976. Water Quality network 1975 summary of data Volume 2. Illinois Environmental Protection Agency, Springfield. 245 p. Junk, W.J., P.B. Bayley, and R.E. Sparks. 1989. The flood pulse concept in river-floodplain systems. Pages 110-127 in D.P. Dodge, ed. Proceedings of the International Large River Symposium. Cana- dian Special Publication Fisheries and Aquatic Science 106. . 1981. Ecological perspective on water quality goals. Environmental Management 5(1):55-68. Karr, J.R., and L.J. Schlosser. 1978. Water resources and the landwater interface. Science 210:229-234. FLOWING WATERS Karr, J.R., K.D. Fausch, P.L. Angermeier, P.R. Yant, and I.J. Schlosser. 1986. Assessing biological integrity in running waters: a methods and its rationale. Illinois Natural History Survey Special Publication 5. Illinois Natural History Survey, Champaign. Larimore, R.W., and P.W. Smith. 1963. The fishes of Champaign County, Illinois, as affected by 60 years of stream changes. Illinois Natural History Survey Bulletin 28:299-3872. Lubinski, K.S., R.E. Sparks, and L.A. Jahn. 1974. The development of toxicity indices for assessing the quality of the Illinois River. Water Resources Center, University of Illinois, Urbana-Champaign. Lubinski, K.S., and R.E. Sparks. 1981. Use of bluegill toxicity indexes in Illinois. Pages 324-337 in D.R. Branson, and K.L. Dickson, eds. Aquatic toxicol- ogy and hazard assessment. American Society for Testing and Materials, Philadelphia, PA. 471 p. Matthews, W.J., and L.G. Hill. 1977. Tolerance of the red shiner, Notropis lutrensis (Cyprinidae), to environmental parameters. Southwestern Natural- ist 22(1):89-98. Mills, H.B., W.C. Starrett, and F.C. Bellrose. 1966. Man’s effect on the fish and wildlife of the Illinois River. Illinois Natural History Survey Biological Notes No. 57. 24 p. Morris, M.A., R.S. Funk and P.W. Smith. 1983. An annotated bibliography of the Illinois herpetologi- cal literature 1960-1980, and an updated checklist of species of the state. Illinois Natural History Survey Bulletin 33:123-137. Murphy, B.R., D.W. Willis, and T.A. Springer. 1991. The relative weight index in fisheries manage- ment: status and needs. Fisheries 16:30-38. Naiman, R.J., and H. DeCamps. 1990. The ecology and management of aquatic-terrestrial ecotones, vol. 4. Parthenon Pub. Group, Park Ridge, New Jersey. O’Brien, W.P., M.Y. Rathburn, P. O’Bannon, C. Whitacre eds. 1992. Gateways to commerce. National Park Service, Denver. 238 p. O’ Hara, M.G. 1980. The founding and early history of the pearl button industry. Pages 3-10 in J. L. Rasmussen, ed. Proceedings of the UMRCC symposium on Upper Mississippi River bivalve mollusks. May 1979. Upper Mississippi River Conservation Committee, Rock Island, Illinois. Osborne, L. L., and M. J. Wiley. 1988. Empirical relationships between land use/cover and stream water quality in an agricultural watershed. Journal of Environmental Management 26:9-27. 222 Osborne, L.L., P.B. Bayley, D.C. Dowling, R.W. Larimore, C. Nixon, J.T. Peterson, D. Szafoni, and D. Wood. 1991. The fishes of Champaign County (Final Report F-76-R). Aquatic Ecology Technical Report 91/5. Illinois Natural History Survey, Champaign. 142 p. Page, L.M., and R.L. Smith. 1970. Recent range adjustments and hybridization of Notropis lutrensis and Notropis spilopterus in Illinois. Transactions of the Illinois State Academy of Science 63:264-272. Page, L.M. 1985. The crayfishes and shrimps (Decapoda) of Illinois. Illinois Natural History Survey Bulletin 33(4):335-448. Page, L.M. 1991. Streams of Illinois. Pages 439-446 in L.M. Page and MLR. Jeffords, eds. Our living heritage: the biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4). Page, L.M., K.S. Cummings, C.A. Mayer, S.L. Post, and MLE. Retzer. 1992. Biologically significant Illinois streams: an evaluation of the streams of Illinois based on aquatic biodiversity. Illinois Natural History Survey Center For Biodiversity Technical Report 1992(1). Champaign, Illinois. Page, L.M., K.S. Cummings, C.A. Mayer, S.L. Post, and MLE. Retzer. 1992. An evaluation of the streams of Illinois based on aquatic biodiversity. Pages 402-417 in Biologically significant Illinois streams. Illinois Department of Conservation and Illinois Department of Energy and Natural Resources, Springfield. Parmalee, P.W. 1967. The freshwater mussels of Illinois. Popular Science Series vol. 8. Illinois State Museum, Springfield. 108 p. Patterson Schafer, Inc. 1991. Report No. 91-37: comprehensive evaluation of water quality in the Chicago man-made waterway system 1990. Metropolitan Water Reclamation District of Greater Chicago, Chicago, Illinois. Polls, I., S.J. Sedita , D.R. Zenz, and C. Lue-Hing. 1991a. Report No. 91-21: comprehensive evalua- tion of water quality along the Illinois Waterway at Lockport, Morris, Starved Rock, Henry, and Peoria during 1990. Metropolitan Water Reclama- tion District of Greater Chicago, Chicago, Illinois. Polls, I., S.J. Sedita , D.R. Zenz, and C. Lue-Hing. 1991b. Report No. 91-24: comprehensive evalua- tion of water quality along the Illinois Waterway at 49 sampling stations from the Lockport Lock and Dam to the Peoria Lock and Dam during 1990. Metropolitan Water Reclamation district of Greater Chicago, Chicago, Illinois. Richards, T.E., P.D. Hayes, and D.J. Sullivan. 1991. Water resources data Illinois water year 1990 Volume 2. Illinois River Basin. U.S. Geological Survey, Urbana, Illinois. Roseboom, D.P., T.E. Hill, J.D. Beardsley, J.A. Rodsater, L.T.Duong, R.B. Hilsabeck, R.P. Stowe, R.W. Sauer, D.M. Day, J.A.Lesnak. 1992. Value of instream habitat structures to smallmouthbass. Illinois Department of Conservation, Aledo, Illinois. Ross, H.H. 1944. The caddis flies, or trichoptera, of Illinois. Illinois Natural History Survey Bulletin 23(1):1-326. Schlosser, [.J., and J.R. Karr. 1981. Riparian vegetation and channel morphology impact on spatial patterns of water quality in agricultural watersheds. Environmental Management 5:233-243. Smith, H.M. 1899. The mussel fishery and pearl button industry of the Mississippi River. Bulletin of the U.S. Fish Commission 18:289-314. Smith, P.W. 1961. The amphibians and reptiles of Illinois. Illinois Natural History Survey Bulletin 28:1-298. Smith, P.W. 1971. Illinois streams: A classification based on their fishes and an analysis of factors responsible for the disappearance of native species. Illinois Natural History Survey Biological Notes 76. 14 p. Smith, P.W. 1979. The fishes of Illinois. University of Illinois Press, Urbana. 314 p. Sparks, R.E. 1977. Environmental inventory and assessment of navigation pools 24, 25, and 26, Upper Mississippi and lower Illinois rivers. An electrofishing survey of the Illinois River. Univer- sity of Illinois Water Resources Center, Champaign, Illinois. UILU-WRC-77-0005. Special Report No. 5. Sparks, R.E. 1982. The role of contaminants in the decline of the Illinois River: Implications for the Upper Mississippi. /n J.G. Wiener, D.R. McConville, and R.V. Anderson, eds. Contami- nants in the Upper Mississippi River. Butterworth Publishers, Stoneham, Massachusetts. Sparks, R.E. 1984. The role of contaminants in the decline of the Illinois river: Implications for the Upper Mississippi. Pages 25-66 in J.G. Wiener, R.V. Anderson, and D.R. McConville, eds. Contaminants in the Upper Mississippi River. Proceedings of the 15th Annual Meeting of the Mississippi River Research Consortium. Butterworth Publishers, Stoneham, Massachusetts. 368 p. FLOWING WATERS Sparks, R.E. 1991. Zebra mussel update. Illinois Natural History Survey Reports No. 311. Champaign, Illinois. Sparks, R.E. 1992. Risks of altering the hydrologic regime of large rivers. Pages 119-152 in J. Cairns, Jr., B.R. Niederlehner, and D.R. Orvos, eds. Predicting ecosystem risk. Advances in modern environmental toxicology. Volume 20. Princeton Scientific Publishing Company, Princeton, New Jersey. 347 p. Sparks, R.E., P.B. Bayley, S.L. Kohler, and L.L. Osborne. 1990. Disturbance and recovery of large floodplain rivers. Environmental Management 14(5):699-709. Sparks, R.E., and E. Marsden. 1991. Zebra mussel alert. Illinois Natural History Survey Reports No. 310. Champaign, Illinois. Sparks, R.E., P.E. Ross, and F.S. Dillon. 1992. Identification of toxic substances in the Upper Illinois River. Final report. Illinois Department of Energy and Natural Resources. Contract No. WR36. 60 p. Sparks, R.E., M.J. Sandusky, and A.A. Paparo. 1981. Identification of the water quality factors which prevent fingernail clams from recolonizing the Illinois River, Phase II. University of Illinois Water Resources Center Research Report No. 157. 52 p. Starrett, W.C. 1971. A survey of the mussels (Unionacea) of the Illinois River, a polluted stream. Illinois Natural History Survey Bulletin 30:267-403. Starrett, W.C. 1972. Man and the Illinois River. In R.T. Oglesby, J.A. McCann, and C.A. Carlson, eds. River ecology and man. Academic Press, New York. Suloway, L., J.J. Suloway and E.E. Herricks. 1981. Changes in the freshwater mussel (Mollusca: Pelecypoda: Unionidae) fauna of the Kaskaskia River, Illinois, with emphasis on the effects of impoundment. Transactions of the Illinois State Academy of Science 74:79-90. Tazik, P.P., and S.T. Sobaski. 1992. Des Plaines River long-term monitoring program: vegetation analysis and habitat characterization (final report). Aquatic Ecology Technical Report 92/1. Illinois Natural History Survey, Champaign. 39 p. Thompson, D.H., and F.D. Hunt. 1930. The fishes of Champaign County, Illinois: a study of the distribution and abundance of fishes in small streams. Illinois Natural History Survey Bulletin 19:1-101. FLOWING WATERS _____———————————————— Vannote, R.L., G.W. Minshall, K.W. Cummins, J.R. Sedell, and C.E. Cushing. 1980. The river con- tinuum concept. Canadian Journal of Fisheries and Aquatic Sciences 37:130—137. Vinyard, G.L., and W.J. O’Brien. 1976. Effects of light and turbidity on the reactive distance of bluegill (Lepomis macrochirus). Journal of the Fisheries Research Board of Canada 33:2,845-2,849. Ward, J. V. 1984. Ecological perspectives in the management of aquatic insect habitat. Pages 558— 577 in V. H. Resh, and D. M. Rosenberg, eds. The ecology of aquatic insects. Praeger Publishers, New York. Ward, J. V., and J. A. Stanford, eds. 1979. The ecology of regulated streams. Plenum Press, New York. Ward, J.V., and J.A. Stanford. 1983. The serial discontinuity concept of lotic ecosystems. Pages 29-42 in T.D. Fontaine and S.M. Bartell, eds. Dynamics of lotic ecosystems. Ann Arbor Science Publishers, Ann Arbor, Michigan. Waters, S.J. 1980. The evolution of mussel harvest regulations on the Upper Mississippi River. Pages 191-201 in J. L. Rasmussen, ed. Proceedings of the UMRCC symposium on Upper Mississippi River bivalve mollusks. May, 1979. Upper Mississippi River Conservation Committee, Rock Island, Illinois. 270 p. Wiley, M.J., L.L. Osborne, and R.W. Larimore. 1990. Longitudinal structure of an agricultural prairie river system and its relationship to current stream ecosystem theory. Canadian Journal of Fisheries and Aquatic Sciences 47:373-384. 224 RESOURCE ANALYSIS SUMMARY Environmental assessment should include a status report on renewable and nonrenewable resources. For a renewable resource, we ask whether the stock (the “natural capital”) is maintained so that the resource is truly renewable. For a nonrenewable resource, we ask how long we can expect the resource to last at the anticipated rate of consumption. We address these questions for the following: * Renewable resources Soil Forests Ethanol ¢ Nonrenewable resources Coal Oil Natural gas We also scrutinize trends in: * Pollution Energy/CO, production Fossil/solar energy ¢ Consumption and lifestyle Motor vehicles Recycling This list is only a beginning for future, more complete accounting. For resources, the most basic indicator is static life- time, which is the length of time the resource will last at today’s consumption rate and today’s discovery or replenishment rate. We acknowledge three difficulties with this approach: 1. Future consumption will change. If it increases, the lifetime is less than the static lifetime. 2. The “amount of resource” is an imprecise number that depends on economic conditions and on technological change. 3. The efficiency with which we use the resource can change, so that static lifetime is an imperfect indicator of the useful lifetime to citizens. Additionally, we note that the amount of a resource should be balanced against the consequences of using it. The static lifetime for Illinois coal used to satisfy Illinois demand is measured in hundreds of years, which is auspicious, yet coal combustion yields more carbon dioxide per unit of energy than any other fuel, which is problematic. We find: ¢ Renewable resources Soil. On average, erosion rates are so small (approxi- mately 0.03 inches/year) that Illinois soil will last hundreds of years. However, this varies across coun- ties; some are so steep and eroding so fast that the soil lifetime is just several decades. Erosion rates decreased from 1982 to 1987. In many counties, the percent change in cropland acreage exceeds the percent change in soil depth from erosion; in that case it is land-use change that dominates the change in the “volume” of available soil. Forests. Wood volume increased from 1962 to 1985. Harvest rates increased, however, so that net accumula- tion in 1985 was negative. Ethanol. Ethanol production has grown over the past 15 years to now equal approximately one-sixth of Illinois’ liquid road fuel use. Net energy considerations complicate considering this fuel renewable, however. ¢ Nonrenewable resources Coal. Illinois has enough coal for approximately several hundred years’ in-state consumption at current rates. Oil. Illinois has enough oil for approximately one year’s in-state consumption at current rates. Natural gas. Illinois’ reserves are very small and not formally evaluated. Illinois’ annual production (as a byproduct of oil production) is approximately 0.1% of its in-state consumption. RESOURCE ANALYSIS ¢ Pollution Energy/CO, production. Illinois uses approximately 1% of the world’s energy and produces approximately 1% of the world’s energy-related CO,,. In the 1980s energy consumption decreased, with the decrease dominated by reduced oil consumption following large increases in the world oil price. The ratio of CO, to energy decreased in the period 1960-1990 because of (1) a trend away from coal toward oil and natural gas in 1960-1980 and (2) an increase in the amount of electricity produced from nuclear power plants in 1970-1990. A simple projection to the year 2000 shows Illinois energy use holding steady or increasing slightly, but a decrease is possible depending on economic growth and increased energy efficiency. Fossil/solar energy. This ratio is a broad, approximate indicator of overall environmental impact. In Illinois, fossil energy consumption amounts to about 6% of the incoming solar energy at the ground. This ratio is 600 times higher than in the world as a whole. Indirect evidence indicates that in highly urbanized areas, the fossil/solar energy ratio is approximately 1. ¢ Consumption and lifestyle Motor vehicles. Vehicles use 24% of Illinois’ energy and produce 29% of its energy-related CO,. While human population growth in Illinois was 0.0036% per year during 1980-1990, the automobile population grew at 0.094% per year, and the number of all motor vehicles grew at 0.49% per year. At the same time the number of buses decreased at 3.5% per year. There are now 0.55 automobiles per capita and 0.69 motor vehicles per capita. A simple projection to the year 2000 shows Illinois auto registration increasing at an average rate of 0.094% per year. Recycling. We have only meager data on the trend in recycling at recycling centers. The total tonnage recycled at recycling centers, from a voluntary- response survey done by the Illinois Environmental Protection Agency, is 8% of Illinois’ solid waste production, by weight. 226 SOIL Soil erosion diminished from 1982 to 1987, as shown in Figure 1, which covers cultivated and uncultivated cropland in Illinois’ 102 counties, as categorized by the Soil Conservation Service (1992). Table 1 and Figures 2 and 3 show erosion rates by county for 1982 and 1987. Figures 4 and 5 show the change and the percent change in erosion rates, respectively. The soil loss is converted to depth decrease for comparison with the actual depth of Illinois soils, assuming that soil has a specific gravity of 1.35. While soil depth is somewhat variable in definition, it is typically measured at around 10 inches, whereas the erosion rates in Figure 1 average no more than 0.03 inches per year. In Table 2, the static lifetime of the soil resource is calculated two ways: 1. Depth/erosion rate 2. Depth/(erosion rate - T), where T is the rate of formation of new soil from bedrock. T is normally assumed to be 5 tons per acre per year (Soil Conservation Service 1992), which is SOIL EROSION STATISTICS 0.3 0.25 = re) EROSION (INCHES / YEAR) _—J © Bn -_ wn 0.05 1982 1987 Figure 1. Statistical summary of erosion rates on cultivated and uncultivated cropland in Illinois’ 102 counties, 1982 and 1987. County figures were weighted by cropland acreage. The barred range indicates values ] standard deviation around the mean. Original data, in tons per acre per year, were converted to thickness using a specific gravity of 1.35. Source: Soil Conservation Service 1992. Table 1. Soil erosion data by county, 1982 and 1987. Erosion figures in tons per acre per year were converted to inches per year using a soil specific gravity of 1.35. CU and UC indicate cultivated and uncultivated cropland, respectively. Source: Soil Conservation Service 1992. 1982 1982 1982 1982 1982 1982 1982 COUNTY ACRES CU+UC CU + UC FOREST FOREST PASTURE PASTURE COUNTY (THOUSAND = EROSION (THOUSAND EROSION (THOUSAND EROSION EROSION ACRES) (IN/ ACRES) (IN/ ACRES) (IN/ TOTAL YEAR) YEAR) YEAR) (INCHES/ YEAR) G 0.045 0.030 0.055 908 0,022 194458.61_ 0.039 §54217.99 0,049 178539.65 0.282 295992.12 9,059 CASS. 243333.89 0.037 CHAMPAIGN 632145.7: 0,023 CHRISTIAN 452858.5 0.029 CLAR 318B50.78 0,021 _297120.51 0.018 8628. 0.023 0.033 0.028 0.029 0.023 0.043 0.042 0.022 0.033 0.031 0.042 0.020 0.022 0.025 0.060 0.033 0.037 0.052 72948.32: ee # He 0:000 | Dh 0.012 275993.56 0.026 514490,98 FEO O50 ee | 2 0.011 0.037 112270.69 2b.3 0.123 37.2 0.005 0.034 _ 250351,04 = 136,8 0.046 23,6 0,007 0,033 112270.69 = 21.3 0.123 i ae 0.005 0.034 25036104 1368 8 8=©0,046 236 0,007 0,033 523024.15 424.7 0.076 46.2 0.001 0.070 “FOBB78 663.2 0.022 Oe 0,001 0,021 i 382249.86 182.8 0.056 80.8 0.016 0.038 815429.42 += -198.7 0,035 85.9 0,005 0,023 c : A 369633.89 178 0.069 54.6 0.015 0.042 UEPSEY——“ —“is'eeee7.05 «= 159.2) ieRti“‘i‘é ‘SC TC 0,039 0,050 JODAVIESS 392150.23 218.1 0.086 69.5 0.011 0.062 JOHNSON =—s—“‘aws:s‘“‘éaOOS~=— 281 0.090 85 0,042 0,034 KANE 332582.39 243.7 0.039 3.5 0.003 0.037 ‘KANKAKEE --$31754.42 319.1 0,027 32.3 0,001 0.022 KENDALL 204431.34 154.3 0.027 0.9 0.000 0.023 KNX 485 909,34 293.2 0,040 26.3 . 0,045 0,039 RESOURCE ANALYSIS ____ nN ———— RESOURCE ANALYSIS Table 1 (continued) Fa Macc heed enn na 298141.16 -7a79p4.9 236144.28 LIVINGSTON ‘MACON 370937.76 MACOUPIN 549074.44 MADISON 4 MARION (MARSHALL POPE PULASKI WABASH. WASHINGTON WHITE : 316140.95 WHITESIDE 442457. WILL 538380.06_ ‘WILLIAMSON 281203.8 § WINNEBAGO 329726.59 ‘WOODFORD 5767.8 SUM: 35,657,703 24,728 3,430 3,158 WEIGHTED MEAN: 0.044 0.019 0.017 0.039 STD. DEVIATION: 0.024 0.044 0.020 0.023 228 Table 1 (continued) 1987 1987 1987 1987 COUNTY ACRES CU+UC CU+UC FOREST FOREST (THOUSAND EROSION (THOUSAND EROSION ACRES) (IN/ ACRES) (IN/ YEAR) YEAR) §51303.4 169674.52 242342.9 -179086.2 194458.61 §84217.99 178539.65 _ — p96992.12 __ 243333.89 CHAMPAIGN —ss«&6 32145.79_ CHRISTIAN 452858.5 CLARK i (ws—~*«é BBO. CLAY “e 297120.51 CUNTON = =—«¥3 186 28.41 COLES 323116.63 6072309 _281724.11 MBERL/ - 219488.7 DEKALB 402704.39 459256.89 I ; 308094.19 FRANKUN =——s—s«'73307.82 ‘FULTON 559506.98 GALLATIN. ——s«207042,79 ~~ 346250.12 _ _ 272949.32 275993.56 §14490,98 356.8 0,035 112270.69 20.6 0.144 25035104 = 136.8 0.031 523024.15 424.6 0.052 708878 6657 0.011 _382249.86 205.8 0.050 - 316429.42 = 200 0.029 369633.89 175.8 0.069 920833.08 = 27.1 0.080 332582.39 238.5 0.032 431784.42 © 320.2 0,016. 204431.34 155 0.027 455909.34 301.8 0.035 298141.16 74.5 0.043 - 7270840 560.7 0.026 RESOURCE ANALYSIS _____ 1987 1987 PASTURE PASTURE (THOUSAND — EROSION ACRES) (IN/ YEAR) L M 126.1 0.008 0 0,000 5.9 0.072 37.4 0,005 46.4 0.027 42.4 9,001 2.2 0.017 ae 28.8 9,009: 2.9 0.004 14 0,000 5.9 0.014 274 0,005 17.6 0.001 fy) 0,000 0.6 0.018 22.5 0,001 25.9 0.002 6.5 0,018 2.9 0.028 1.6 0.054 1.2 0.027 10.2 0.000 23 0.012 21.1 0,004 28.6 0.010 Al. 0,012 i) 0.000 10.1 0.007 46.7 0.010 16.7 0.059 15.2 0.027 21,6 0.000 35.3 0.007 51,5 0.033 27.7 0.005 63.9 0.006 9.9 0.000 3.9 0.001 10.2 0.039 9.6 0,005 92.1 0.014 31.5 0,028 55 0.011 80.5 0,042 6.1 0,003 31.4 0,001 29.7 0.000 88.4 0,016 21.8 0.001 78.7 0,001 1987 COUNTY EROSION TOTAL (INCHES/ %CH/YR IN LAND USE CU +UC AVER OVER 5 YEARS ——— RESOURCE ANALYSIS Table 1 (continued) H | K L M N Oo LAWRENCE 236144.28 208 0.033 0.000 8.7 0.003 0.030 0.30 VE s—s—=—SSSCs 482200.31 8.000 =~ 9,023 2.37 LIVINGSTON 662753.32 8.1 0.001 0.017 0.03 AOGAN 991872.9 1a 0.004 0.012 0.04 MCDONOUGH 373708.68 Tit 0.006 0.026 0.00 MCHENAY. 387904.88 Hye a 0.003 0.033 1.81 MCLEAN 751386.77 0 0.000 0.026 0.51 MACON 370937.768 i) 0.000 0.028 0.02 -MACOUPIN 549074.44 67.7 0.031 0.034 1.24 MADISON © 468480.01 30.2 0.041 0.046 -0.23 MARION 364631.58 22.2 0.007 0.025 4.39 MARSHALL =—s—“i«‘<éS BBB B11 0.002 0.034 0.73 MASON 355729.24 6.7 0.001 0.021 -0.06 ‘MASSAG 4B 179B.07 39.8 0.015 0.033 1,59 MENARD ; 199601.01 23 0.043 0.041 0.26 MERCER / 359574.34.: $9.7. 0.097. 0.070 0.17 MONROE 251430.62 2.3 0.065 0.076 0.11 MONTGOMERY —si“‘“‘ié 44‘ 24.4 0.018 0.020 2.54 MORGAN ___ 362701.04 13.5 0.037 0.077 1.69 MOULTRIE 217812,79 58 0.002 0.013 0,02 484562.7 8.6 0.001 0.036 0.53 ‘PEORIA 399181,89" 0.015 0.035 -0.28. PERRY 283094.81 0.005 0.037 0.48 PIATT. “RIBISS.A7 0,001... 0.022 0.02 PIKE 535799.98 0.005 0.041 0.28 POPE - 936020.60 0.023 0,030. =-2.01 PULASKI ? 127330.62 0.003 0.070 0.44 ‘PUTNAM - 109133.46 9,001 9,022 0.00 RANDOLPH 373761.41 0.009 0.044 -0.37 RICHLAND =—i(‘iés RG BT 0,020 0,038 0.42 ROCKISLAND _284887.47 0.003 0.024 -1.33 ST.CLAIR. -426684.0 | 9,033. ——ss«0,045 0.68 SALINE 245037.97 0.016 0.026 1.41 SANGAMON © _) 855423.3 0,013. 0.037. 0.83 SCHUYLER 279498.61 0.014 0.034 1.59 SCOTT 159637.32 0.012 0,039 0.03 SHELBY 486372.58 0.003 0.025 -0.12 STARK -182825.50 9,008 0,047. --0.08 358412.29 0.003 0.019 -0.02 0,025 “0,028 —_--0.01 0.022 —_—0.033 0.57 VERMILION B70284.03 0.022 0,016 —— 0.03 WABASH ; 143242.57 0.008 0.026 0.12 WARREN (344530.17 46 0.012. 0.020 1.53 WASHINGTON 356935.6 4 0.018 0.026 0.00 WAYNE == 452959.55 332.7. 21.2 0,003. 0.016 -0.48 WHITE 316140.95 197.8 70.4 0.006 0.021 2.87 WHITESIDE. ° -$42417,72.. 387 3.2... 0.129 0.031 0.09 WILL §38380.06 334 33.7 0.005 0.018 -0.28 WILLIAMSON . -281203.8 89.1 65.7 «0.037. 0,045 0.34 WINNEBAGO 329726.59 239.1 44 0.003 0.031 -0.07 WOODFORD. 336767.88 284.3 3.9 0.004 0.020 0.04 SUM: 35,657,703 25,121 2,689 WEIGHTED MEAN: 0.034 0.015 0.015 0.030 STD. DEVIATION: 0.017 0.024 0.018 0.015 230 0.9 to .1 -0.1 to .5 -0.6 to .9 -1.0 to 1.9 -2.0 to 2.9 LE -3.0 [__] No CHANGE Figure 2. Erosion by county, 1982 (values given in tons Figure 4. Change in erosion, 1982—1987 (values given per acre per year). in tons per acre per year). -1 to -10 -11 to -20 -21 to -30 -31 to -40 -41 to -60 NO CHANGE Figure 3. Erosion by county, 1987 (values given in tons Figure 5. Percent change in erosion, 1982-1987. per acre per year). RESOURCE ANALYSIS ____ 231 RESOURCE ANALYSIS Table 2. Soil depths and static lifetimes for 42 counties using A-horizon thickness. A-horizon depths are averages from the maximum and minimum A-horizon depths. Soil is assumed to have a specific gravity of 1.35. An asterisk in a static lifetime column indicates that soil is accumulating faster than it erodes. Static Static Soil depth lifetime _ lifetime Erosion rate (inches) in years in years County 1987 A-horizon A-horizon A-horizon name (inches/yr) cty surveys with T without T Adams 0.027 5.87 - 221 Alexander 0.025 4.53 “2 179 Bond 0.054 4.06 192 75 Broone 0.020 6.20 x 307 Brown 0.031 3.35 ‘e 109 Calhoun 0.137 S221 31 23 Carrol 0.043 8.00 814 187 Champaign 0.014 7.50 = 551 Clark 0.017 7.83 %; 456 Dekalb 0.037 6.70 1616 181 Douglas 0.022 7.23 2 327 DuPage 0.026 4.54 x 178 Gallatin 0.032 Sky = 182 Greene 0.036 7.29 2116 200 Grundy 0.012 7.44 = 625 Hamilton 0.023 3.87 # 169 Hardin 0.047 3.97 279 84 Henry 0.049 6.69 413 136 Iroquois 0.011 7.25 & 657 Jackson 0.038 5.00 1035 132 Jersey 0.045 7.45 609 165 Kane 0.031 6.49 = 210 Kankakee 0.013 ifEe) BF 572 ‘La Salle 0.022 7.12 x 319 Lee 0.023 6.50 = i284 Madison 0.046 4.36 325 94 Massac 0.033 4.99 * 152 Mercer 0.070 6.04 164 86 Morgan 0.077 6.32 142 82 Ogle 0.036 7.78 2631 217 Perry 0.037 2.97 821 81 Pope 0.030 Shay) 2 119 Pulaski 0.070 5.19 141 74 Saline 0.026 5.48 is 214 Sangamon 0.037 7.86 2051 214 Scott 0.039 5.42 877 139 Stephenson 0.019 Test “i 409 St. Clair 0.048 6.15 535 138 Union 0.033 3.94 * 120 Wabash 0.026 6.42 * 243 Winnebago 0.031 6.34 = 205 Source: Soil Conservation Service 1992. 232 equivalent to 0.033 inches per year. We assume T is the same for all locations. In Table 2, soil depth is that to the “A-horizon,” which corresponds well with the concept of organic soil that is capable of supporting agricultural production without extensive fertilization. Strictly speaking, this is richer than, and therefore not equivalent to, the soil being formed by breakdown of bedrock. Thus, calculat- ing static lifetime with T reflects an optimistic view of soil lifetime, and calculating without T reflects a pessimistic view. In general, static lifetimes are hundreds of years. On the time scale of human generations, soil erosion is therefore not a pressing issue from the standpoint of depletion. Soil erosion’s effect on stream quality, river siltation, blockage of navigation channels, etc., can be a pressing issue, as covered elsewhere in this volume. Further, as shown in Figure 1, the erosion rate decreased from 1982 to 1987. In contrast, in some counties a more important influence on the soil “stock” is changing land use patterns. Columns A, C, and E for 1982 and Columns H, J and L for 1987 of Table 1 show that area changes are approximately 10 times as large (on a fractional basis) as depth changes from erosion. For example, from 1982 to 1987 the statewide acreage of cultivated and uncultivated cropland actually increased approximately 1.5% (while areas of pasture decreased). Cropland area changes must, of course, be evaluated relative to changes in land for other environmentally desirable uses such as forests and wetlands. Table 3 shows the average annual depth and area changes for several counties during 1982-1987, using the rate of soil loss corrected or uncorrected for T. These are chosen as examples because the fractional area changes are relatively large. Table 3. Annual change in soil depth and in cropland area for four selected Illinois counties, 1982-1987, based on A-horizon soil depth. Change in Change in soil depth soil depth Change in per year per year cropland area County with T without T per year Adams -0.194% -0.756% -2.1% Brown -0.516% -1.501% -2.1% Lee 0.031% -0.477% 2.4% Jackson -0.404% -1.064% 2.5% FORESTS Forests are a potentially renewable resource that benefits the Illinois economy and environment. Beyond income from timber harvests, Illinois forests create income from tourism at county and state forests and parks and national forests. Forests help clean the air and water, they help stabilize soil and water, and they provide habitat for Illinois’ diverse wildlife. Before settlement, forests occupied 13.8 million (39%) of Illinois’ 35.6 million acres of land (Figure 6). By 1962 there were only 3.8 million acres of forested land (11% of Illinois). From 1962 to 1985 this increased to 4.26 million acres (12% of Illinois). Commercial forested land is classified as forested area that produces or is capable of producing timber for industrial harvest. In 1962, Illinois had 3.7 million acres of commercial forested land (97% of total forested land) (Figure 7). By 1985, the amount of commercial forested land had increased to 4 million acres (93% of total forested land). In 1962 annual growth in commercial forested areas exceeded than the amount harvested. In 1985, however, this was reversed: more timber was harvested than was added by new growth (Figure 8). The change in forest management techniques is shown by the change in forest biomass reserves. In 1962, Illinois had a net increase in commercial forest biomass of 1.45% per year (Figure 9). In 1985, Illinois had a net loss of commercial forest biomass reserves of 2.44% per year. ETHANOL FROM GRAIN The amount of ethanol produced in Illinois from grain has increased steadily since the late 1970s (Figure 10). Today’s in-state production of 1 billion gallons uses 400 million bushels of corn, which is 31% of the state’s corn production. Ethanol from Illinois is used as a gasoline additive in many states. If it all were used in-state, it would be equivalent to one-sixth of Illinois’ liquid road fuel consumption on a volume basis. Ethanol, being made from a crop, is classified as renewable energy, but there is continued controversy about how justified this title is. The question is one of “net energy,” recognizing that corn production and the RESOURCE ANALYSIS FOREST LAND MILLION ACRES SIZE OF ILLINOIS 1962 1985 SEPCLEMENT Figure 6. Forested land in Illinois. Even in pre- settlement times, only 39% of Illinois was forested. Today 12% is forested. Sources: Essex and Gansner 1965, Hann 1987, Iverson et al. 1985. COMMERCIAL FORESTED LAND MILLION ACRES 1962 1985 Figure 7. Commerical forested land, 1962 and 1985. Sources: Essex and Gansner 1965, Hann 1987, Iverson et al. 1985. FOREST BIOMASS VOLUME eee oe nw uw an HUNDRED MILLION CUBIC FEET BILLION CUBIC FEET G Morr. & HARV. IN THAT YEAR (RIGHT AXIS) E) GROWTH IN THAT YEAR (RIGHT AXIS) 1) TOTAL BIOMASS VOLUME (LEFT AXIS) Figure 8. Biomass volume, yearly growth, and yearly mortality plus harvest for 1962 and 1985. In 1962 growth exceeded mortality plus harvest. In 1985 the opposite was true. Sources: Essex and Gansner 1965, Hann 1987, Iverson et al. 1985. FOREST BIOMASS FOREST BIOMASS »_ - oc = w& oe 1962 1985 ANNUAL PERCENT CHANGE IN Figure 9. Net change in forest biomass, 1962 and 1985. Sources: Essex and Gansner 1965, Hann 1987, Iverson et al. 1985. ETHANOL PRODUCTION and FUEL CONSUMPTION Fuel Consumption 1975 1980 Ethanol Production cCcrnweunn~ BILLION GALLONS PER YEAR 1985 1990 YEAR Figure 10. Illinois ethanol production, 1975-1992. Source: Illinois Corn Growers Association. conversion of corn to ethanol both require large fossil fuel energy inputs. The answer depends on what data are used, what conceptual boundaries are chosen, and several other issues. One research group found ethanol close to producing zero net energy (Chambers et al. 1979). Another found that positive net energy results (Goering 1992). COAL Coal use and the quality of the environment are intricately linked. For example, coal use in Illinois creates 31% of the energy-related CO, and approxi- mately nine-tenths of the SO,(USEPA 1991). Illinois has about 10% of the nation’s coal reserves and today accounts for 5% of coal production in the United States. The history of coal production in Illinois follows closely the history of coal production in the United States. Production increased dramatically up through World War I and then fell off during the economic depression of the 1930s (Figure 11). During World War II the demand for coal surged, and by 1944 Illinois produced 70 million tons per year. Illinois, as well as the nation, felt the slump in the coal market in the 1950s. Production increased in the 1960s and 1970s as the demand for electricity increased. Production of coal has remained fairly constant since 1970 except for a drop in the early 1980s. Consumption of coal in Illinois reached a peak in 1969 of 45 million tons. Since 1969 the consumption of coal has varied from year to year but has generally shown a downward trend. From 1969 to 1990, consumption declined 28%, to 32 million tons per year. Reserves for the state are defined as coal that has high development value, which depends on factors such as 234 RESOURCE ANALYSIS. -?-$--$-- the location, depth, extent, and seam thickness. Coal reserves are difficult to determine; the starting figure for this report is 50 billion tons, which was established in 1976 (Illinois Department of Energy 1982). How- ever, this is likely an overestimate. Accounting for mining and cleaning losses, difficulties with thin seams, and other factors, a more realistic value is between 4 and 20 billion tons (Damberger, 1993, personal communication). Hence we use 20 billion tons, acknowledging its uncertainty. This is equivalent to 1800 tons per Illinois citizen. If spread out evenly over the entire state, it would form a layer 2 inches thick. If it were burned, the CO, produced would represent 2.8% of the present atmospheric CO,,. Illinois coal reserves greatly exceed annual consump- tion. The static lifetime has increased from 555 years in 1960 to 615 years in 1990 (Figure 12). Given the uncertainty of reserves figures, the fluctuations in this COAL @ 25. > ae g Zz 7 205 (e) (Left Axis) = OF 8a Pa) ng iu! wo az ie Ae 10g “ Coal C i é i=] 0a ‘onsumption = (left Axis) 5 0 1830 1850 1870 1890 1910 1930 1950 1970 1990 YEAR Figure 11. Production, consumption, and reserves of coal in Illinois. Note that reserves are in billions of tons, while production and consumption are in millions of tons per year. Sources: Cady 1954, Hopkins and Simon 1974, Illinois Department of Energy 1982, Tweworgy and Bargh 1982, Damberger 1993. COAL STATIC LIFETIME 700 = 600 5 500 = 400 = y 300 E200 & 100 0 1960 1965 1970 1975 1980 1985 1990 YEAR Figure 12. Static lifetime of Illinois coal reserves. Static lifetime is reserves divided by current annual consumption. eee a ee ts RESOURCE ANALYSIS Table 4. Static lifetime of coal, oil, and natural gas for industrialized countries, the world, and Illinois. Europe, North America, and Japan World Illinois Coal 240 years 230 years ~600 years Oil 12 years 30 years ~10 months Natural gas 15 years 60 years <1 month Sources: 1993 Information Please Almanac, World Resources Institute 1993, and this report. trend are not significant. The overall picture is that Illinois has enough coal for hundreds of years at current consumption levels. In Table 4, we compare static lifetime for Illinois, the developed world, and the entire world. All are measured in hundreds of years. OIL Petroleum provides many benefits to the people of Illinois, mainly through transportation and mechaniza- tion of agriculture. It has had a large impact on the environment as well. Oil consumption is responsible for 45% of Illinois’ energy-related CO, releases. Crude oil production in Illinois has been recorded since 1905. In 1908, production was about 34 million barrels per year (Figure 13). After 1908, production dropped until 1938, when the state found new sources. Oil production peaked in 1940 at 148 million barrels. After 1940 production dropped until 1950, when secondary recovery methods were utilized. After a small increase, the production of crude oil dropped steadily with only a small increase in the mid 1980s. Oil reserves are defined as crude oil that is economi- cally recoverable. Crude oil reserves shot up in the 1950s when secondary recovery methods were intro- duced (Figure 13). After a peak in 1960 reserves continued to drop to a level of 143 million barrels in 1988. State crude oil consumption increased from 1957 to a peak of 265 million barrels in 1978 (Figure 13). Consumption dropped until 1985 and then began to increase again. Static lifetime of crude oil reserves dropped steadily from 1960 until the mid-1970s and has remained approximately constant at 0.8 years (Figure 14). Since 1970, Illinois has consumed more oil each year than it has in the ground. This is accomplished by heavy importation of oil. Illinois’ static oil lifetime is 0.8 years, compared 12 and 30 years for the industrialized countries as a whole and for the entire world, respectively (Table 4). NATURAL GAS Natural gas, like crude oil, has an important role in Illinois’ economy and environment. Though natural gas is the least carbon-intensive of the fossil fuels, it creates 23% of the state’s energy-related CO,. The state of Illinois has never been an important producer of natural gas. The production of natural gas is largely dependent on crude oil production, since it is a by-product. Produc- tion of natural gas dropped with crude oil production from 1960 to the early 1970s (Figure 15). As crude oil production stabilized in the 1970s, the amount of natural gas produced increased to a high of 1600 CRUDE OIL Reserves Consumption Production MILLION BARRELS or MILLION BARRELS / YEAR 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 YEAR Figure 13. Production, consumption (in million barrels / year), and reserves (in million barrels) of crude oil in Illinois. Annual consumption slightly exceeds reserves. Sources: Heister and Neely 1987, Bhagwat 1992. CRUDE OIL STATIC LIFETIME STATIC LIFETIME w 1960 1970 1980 1990 YEAR Figure 14. Static lifetime of Illinois oil reserves. Static lifetime is now roughly constant at about | year. RESOURCE ANALYSIS NATURAL GAS Consumption : (Right Axis) g 3 Production (Left Axis) MILLION CUBIC FEET 1 YEAR wu = BILLION CUBIC FEET / YEAR 1960 1970 1980 1990 YEAR Figure 15. Consumption and production of natural gas in Illinois. Reserves are negligible. Note that produc- tion is in million cubic feet per year and consumption is in billion cubic feet per year. Sources: Heister and Neely 1987, Samson 1992, U.S. Department of Energy 1992. million cubic feet in 1973. Production fell in the early 1980s due to the falling production of some of Illinois’ major oil fields. The variation in the late 1980s is accounted for by the number of oil wells that were in operation. Consumption of natural gas in Illinois surged during the late 1960s and early 1970s with a peak of 1229 billion cubic feet in 1972 (Figure 15). At the beginning of the 1980s the consumption of natural gas began to fall, and it reached a low in 1987 of 873 billion cubic feet. The decline of natural gas consumption during the 1980s is partially explained by warm winters. Illinois’ natural gas production is about 0.1% of its consumption, and reserves are negligible (Heister and Neely 1987). Therefore, Illinois’ static lifetime for natural gas reserves is less than one month. (It is possible that there is deep gas as yet undiscovered, but that would likely be much more expensive to produce than today, and it is not included.) Table 4 shows that, compared with Illinois’ value of less than one month, the industrialized world and the whole world have gas static lifetimes of 15 and 60 years, respectively. 236 ENERGY/ENERGY-RELATED CO, RELEASES Illinois’ energy consumption peaked in the late 1970s, just before the second round of world oil price shocks (Figure 16). The reduction from that peak is almost all from reduced oil consumption (Figure 17). Illinois’ energy consumption today is approximately 80% from fossil fuels, which produce CO, (Figure 16). Energy use and resulting carbon dioxide release are not proportional because different fuels vary in their carbon per energy unit (Table 5). Because coal is 1.75 times as carbon intensive as natural gas, it contributes a larger fraction of Illinois’ carbon dioxide production than of energy production. Illinois’ CO, production (237 million tons per year) is about 1% of the world’s total (Lashof and Washburn 1990). For comparison, Illinois’ human population is 0.2% of the world’s. ENERGY CONSUMPTION Total State Energy YEAR QUADRILLION BTU PER 1960 1970 1980 1990 YEAR Figure 16. Total, and fossil-fuel energy consumption in Illinois, 1960-1990. The difference is hydro and nuclear electricity. Source: U.S. Department of Energy 1992. FOSSIL FUEL CONSUMPTION Nuclear Natural Gas TRILLION BTU PER YEAR YEAR Figure 17. Fossil energy consumption in Illinois, 1960-1990. Nuclear energy consumption is included for comparison. Source: U.S. Department of Energy 1992. Production of CO, in Illinois reached a peak in the late 1970s but then quickly dropped in the early 1980s with a decline in the consumption of energy, particularly petroleum (Figure 18). Energy consumption and CO, production stayed nearly constant through 1990. Note that CO, figures in this section are only related to fossil fuel use. Thus, overall state production of CO, is higher than portrayed in these figures. The ratio of released CO, to consumed energy de- creased in 1960-1990 (Figure 19). Major causes were (1) a shift from coal toward oil and natural gas, both of which are less carbon-intensive, in 1960-1980 and (2) an increase in the production of electricity from nuclear power plants, a process that produces little or no CO, in 1970-1990. The latter trend is evident in Figure 17. Against this overall trend, there was a small rise in the mid-1980s because the increase in the world oil price caused a disproportionate decrease in oil consumption. CARBON DIOXIDE PRODUCTION FROM ENERGY CONSUMPTION Total CO2 Production MILLION TONS OF CARBON DIOXIDE / YEAR Figure 18. Energy-related carbon dioxide releases, 1960-1990. Carbon dioxide weighs 3.67 times as much as carbon. Source: U.S. Department of Energy 1992. RATIO OF TOTAL CARBON DIOXIDE TO TOTAL ENERGY TON CO2/ MILLION BTU 1960 1970 1980 199 YEAR Figure 19. Ratio of energy-related CO, production to energy consumption in Illinois, 1960-1990. Source: U.S. Department of Energy 1992. RESOURCE ANALYSIS Figure 20 shows several simple projections (not predictions) for Illinois energy use. It is assumed that: Energy = (population) ¢ (per capita gross state product) * (energy per unit of gross state product). The following assumptions are made about these three factors as shown in Figure 21: 1. Population. We assume a very low growth rate, as given in the 1993 Information Please Environmen- tal Almanac (0.0032% per year). . Per capita gross state product (GSP). Growth rate is obtained from extrapolating the GSP from 1980 to 1990; growth rate is 1.89% per year. . Energy/GSP. This is the energy intensity of the Illinois economy, which has been decreasing. We use three scenarios for continued decreasing energy intensity: -1% per year, —-2% per year, and —3% per year. The first figure is relatively conservative, while —3% is at the outer edge of energy efficiency enthusiasts’ projections (Bureau of Economic and Business Research 1992, U.S. Department of Energy, 1992). N Wo As Figure 20 shows, the projections range from growth to a decrease in Illinois energy consumption. A Table 5. Carbon content of fossil fuels. Carbon content in tons per million BTU Carbon content in Fuel (unit) tons per unit Coal (ton) 0.6050 0.0275 Oil (barrel) 0.1299 0.0224 Natural gas 0.0163 0.0157 (thousand cu ft) PROJECTED ILLINOIS ENERGY USE QUADRILLION BTU PER YEAR 1960 1965 1970 1975 1980 1985 1990 1995 2000 YEAR Figure 20. Several state energy use projections through the year 2000. Percentages refer to assumed annual change in energy/GSP. RESOURCE ANALYSIS GSP PER CAPITA AND ENERGY PER GSP GSP/ CAPITA SS ENERGY / GSP THOUSANDS 1980 1985 1990 1995 2000 Figure 21. Assumptions for GSP/capita and energy/ GSP used in scenarios. PROJECTED CARBON DIOXIDE PRODUCTION FROM ENERGY CONSUMPTION CO2 Production MILLION TONS PER YEAR 1960 1965 1970 1975 1980 1985 1990 1995 = 2000 YEAR Figure 22. Projected carbon dioxide production in Illinois through the year 2000. decrease will require energy per GSP to decrease faster than 2% per year if economic growth is equal to or greater than the projected 1% per year. Given projected energy use, Figure 22 shows projec- tions for Illinois CO, production through the year 2000. It is assumed that: Total CO,/yr = (CO,/ energy) ¢ (total energy use/yr) The projections in Figure 22 range from a 0.08% increase per year to a 0.92% and 1.79% decrease per year in CO, production. It is important to note that if energy use increases over the next 10 years, the production of CO, will increase. This is due to the fact that nuclear power plants in the state are operating near capacity. Since no new nuclear plants are under construction or planned in Illinois, co, per BTU will not continue to decrease as in 1980—1990, when nuclear plants came into operation. 238 RATIO OF FOSSIL TO SOLAR ENERGY In addition to being a direct energy source for plant growth, the sun drives all biospheric processes and thus indirectly supports human activities through the environment’s (1) production of fresh water, (2) production of a hospitable climate, and (3) absorption of our wastes, and so on. A major goal of applied ecology and “ecological economics” is to evaluate this solar dependence and how it is altered by anthropogenic activities. Attempts at detailed quantification of the sun’s role (such as H.T. Odum’s EMERGY analysis [Odum and Arding 1991]) are not accepted (Mansson and McGlade 1993). However, there is justification for using the ratio of (fossil + hydro + nuclear energy) to insolation as an approximate indicator of environmental disruption and impact (Woodwell and Hall 1973, Smil 1991). Annual average solar energy intensity in Illinois is essentially constant, varying only a few percent across the state. A graph of the annual amount of fossil energy consumed versus the amount of solar energy hitting the ground in Illinois is thus proportional to a graph of annual fossil energy consumption, which in Illinois actually decreased in the 1980s. Three points should be made: 1. Illinois’ fossil to solar ratio was 0.06 in the late 1970s; that is, the fossil energy consumed was equal to 6% of direct solar input (Figure 23). The ratio dropped slightly in the 1980s but is now increasing again. 2. The entire world’s fossil to solar ratio is about 0.0001 (1 in 10,000). It is 0.0084 in China and 0.11 in Germany. In Illinois, the fossil to solar ratio is ENERGY USE vs SOLAR INPUT 0.080 LSE Tilinois 0.060 (Left Axis) = = £ Lore SE 2 bs S ~] S = 0.040 2> 38 ae -! Se A 5 is World S.0OE-OS Zz = $6" (Right Axis) sé 0.000 0.008 +00 YEAR Figure 23. Ratio of fossil to solar energy for Illinois and the world, 1960-1990. Sources: Reinke 1993, U.S. Department of Energy 1992, World Resources Institute 1992. therefore about 600 times that of the world as a whole, seven times that in China, and about 55% of that in Germany. 3. We lack data for determining the fossil energy/solar ratio regionally, but it is likely that the ratio is much higher than 0.06 in urban and suburban areas in Illinois. A very rough indicator of how much higher is offered by the data on transportation fuel con- sumption by county in volume 6 of this report (the volume on sources of environmental stress). Fuel use intensity (gallons per acre per year) in 1991 was: Minimum — 8.7 (Schuyler County) Maximum — 3091 (Cook County) Average — 153 (entire state) Cook County’s fuel use intensity was 20.2 times the average. If total energy use is proportional to transpor- tation energy use, then Cook County’s fossil to solar ratio is 20.2 X 0.06 = 1.2. Roughly speaking, therefore, for Illinois’ most urbanized areas, the fossil to solar ratio is of order 1. VEHICLES The automobile, and vehicles in general, bring both benefits and environmental costs to Illinois. We include them as an indicator of environmental impact. Vehicles use 24% of Illinois’ energy and produce 29% of Illinois’ CO, (U.S. Department of Energy 1992). A part of critical trends analysis is therefore appropriately devoted to trends in vehicle use and their fuel-use efficiency. Fuel-use efficiency for all vehicles hit a low of 10.83 miles per gallon in 1976 and then climbed to a high of 14.19 miles per gallon in 1982 in partial response to increasing federal new car fuel efficiency standards (Figure 24). From 1984 to 1990 fleet fuel efficiency dropped to 13.13 miles per gallon, in partial response to the reduced federal new car fuel efficiency stan- dards. Buses use substantially less fuel per passenger mile than cars. The number of buses in Illinois increased steadily from 1940 until 1980, but it has been dropping slowly since (Figure 25). Except for dips at the time of the Great Depression, World War I, and after the Iran- Iraq war of 1979-1980, the number of passenger cars has increased steadily since 1900. The trend is there- fore toward more cars (the more energy intensive road passenger mode, average growth rate = 0.09% per year RESOURCE ANALYSIS for 1980-1990) and fewer buses (the less energy intensive mode, average growth rate = —3.5% per year for 1980-1990). Illinois’ human population has been very nearly constant at 11.4 million since 1980 (average growth rate = 0.036% per year for 1980-90) (Figure 26). The TRANSPORTATION FUEL EFFICIENCY - i) AVERAGE MILES PER GALLON YEAR Figure 24. Fuel efficiency for all vehicles in Illinois, 1960-1990. Source: U.S. Department of Transporta- tion 1980-199]. PASSENGER VEHICLES 8 Rs Automobiles (THOUSANDS) AUTOMOBILES (MILLIONS) BUS & MCYCLE 3 ee ee 0 are 0 1900 «61910 «1920 1930 1940 1950 1960 «1970 1980 1990) YEAR Figure 25. Cars, motorcycles and buses in Illinois, 1900-1990. In 1980-1990, cars increased 0.1% per year while buses decreased 3.5% per year. Source: U.S. Department of Transportation 1980-1991. VEHICLE TRENDS MILLIONS 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 Figure 26. Trends in population, vehicles, cars, and licensed drivers, 1900-1960. Source: U.S. Department of Transportation 1980-1991. RESOURCE ANALYSIS number of cars, which rose about twice as fast as population in 1950-1980, has grown relatively little in 1980-1990, but the total number of road vehicles of all types has continued to grow. As the population “grays,” the number of licensed drivers can be ex- pected to increase even though population has stabi- lized (average growth rate for licensed drivers = 0.42% per year for 1980-1990). Growth of cars/vehicles per capita and cars/vehicles per licensed driver, while slowing relative to the period 1950-1980, is still significant (Figure 27). There are currently (1990) 0.55 cars and 0.69 vehicles per capita. These figures grew at 0.094% per year and 0.49% per year, respectively, in 1980-1990. Transportation fuel use grew steadily from 1950 to 1973, experienced a slight drop after the oil embargo of 1973, and then grew until experiencing a large dip (of 17%) in the 1980s, corresponding to the fuel price increases from the Iran-Iraq war (Figure 28). In the late PER CAPITA VEHICLES Vehicles Per Licensed Drive Cars Per Licensed Drive Vehicles Per Person Cars Per Person 0 c 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 YEAR Figure 27. Per capita vehicles and cars in Illinois, 1950-1990. While their growth is slowing, both cars per capita and vehicles per capita are growing. Source: U.S. Department of Transportation 1980-1991. TRANSPORTATION FUEL USE Fuel Consumed Per Perso: (Right Axis) HUNDRED GAL / PERSON / YEAR Fuel Consumed (Left Axis) 1E+09 GALLONS PER YEAR 0 1950 1960 1970 1980 i998 YEAR Figure 28. Per capita and total transportation fuel use in Illinois, 1950-1990. Source: U.S. Department of Transportation 1980-199]. 240 1980s the world price of oil dropped and transportation energy use climbed back to exceed its previous high. As state population grew only 0.0036% per year in 1980-1990, per capita transportation fuel use grew at 2.1% per year in that period. This reflects the steady growth of vehicles miles traveled in Illinois as de- scribed in volume 6 of this report (the volume on sources of environmental stress). Figure 29 shows a projection of automobile registra- tions in Illinois to the year 2000. This projection (not prediction) combines assumptions about: 1. Population. Very low growth rate, as given in the 1993 Information Please Environmental Almanac (0.0036% / year). 2. Per capita auto registrations. Assumes arithmetic growth at the same rate as for 1980-1990 (0.094% / year). RECYCLING Total solid waste produced for the state in 1992 was 14 million tons (1.2 tons per capita, or 6.5 pounds per capita per day [World Resource Institute 1993]). As landfills fill and disposal fees increase, the need to find a place to put garbage becomes a serious issue to Illinois. A critical trend to monitor is how much waste is recycled. Currently, the state of Illinois does not have complete data on how much is recycled per year at each recy- cling station. Figure 30 was generated using data collected from a survey (with voluntary response) of community recycling stations in Illinois conducted by the Illinois Environmental Protection Agency for the AUTOMOBILE PROJECTION MILLION 1970 1975 1980 1985 1990 1995 2000 Figure 29. Projected human and automobile popula- tions through the year 2000. RESOURCE ANALYSIS Table 6. Data from Illinois Environmental Protection Agency survey of Illinois recycling stations. Year # of surveys sent % of surveys returned 1989 329 29.9 1990 480 19.2 1991 480 31.1 1992 476 41.0 AVERAGE RECYCLED WASTE FOR RESPONDING RECYCLING STATIONS 12 THOUSAND TONS RECYCLED/ YEAR 8 6 4 2 0 1 989 1990 1991 1992 YEAR Figure 30. Average tons per year recycled for respond- ing recycling centers. Data are incomplete; see text. Source: Illinois Environmental Protection Agency 1989-199]. past 5 years (Illinois Environmental Protection Agency 1991). The figures are given in Table 6. The average amount of recycled waste per year for responding stations is shown in Figure 30. This is likely a highly biased statistic, but it is the best available. No clear trend is evident. If we assume that Illinois solid waste production is about 5 Ib per day per person, we can say that the totals in Table 6 are of the order of 8% of Illinois’ solid waste production. LITERATURE CITED Bureau of Economic and Business Research. 1992. 1991 Illinois statistical abstract. Department of Economics, Urbana. Bhagwat, S. 1992. Data diskette on fossil energy. Illinois State Geological Survey, Champaign. Cady, G. 1954. Minable coal reserves of Illinois. Bulletin 78. Illinois State Geological Survey, Champaign. Chambers, R.S., R. Herendeen, J. Joyce, P. Penner. 1979. Gasohol: Does it or doesn’t it.... produce positive net energy? Science 206:789-795. Summed tons per year for responding stations Average tons per year for responding stations 852,211 8,094 715,538 7,856 1,665,065 10,840 1,182,224 6,057 Damberger, H. 1993. Coal: How much is really there? Geotimes, March 1993, p. 16-18. Heister, C., and R. D. Neely, compilers. 1987. The natural resources of Illinois. Special Publication 6. Illinois Natural History Survey, Champaign. Essex, B.L., and D. Gansner. 1965. Illinois’ timber resource. Bulletin LS:3. U.S. Forest Service, Lake States Forest Experiment Station, St. Paul, Minnesota. Goering, C. 1992. Tapping a renewable energy source. Illinois Research 34(1/2):10-14. Hann, J.T. 1987. Illinois forest statistics, 1985. Bulletin MC-103. U.S. Forest Service, North Central Forest Experiment Station, St. Paul, Minnesota. Hopkins, M.E., and T.A. Simon. 1974. Coal resources of Illinois. Illinois State Geological Survey, Champaign. Illinois Department of Energy. 1982. Illinois energy plan: Inventory of coal reserves in Illinois. Vol. 3. Springfield. Illinois Environmental Protection Agency. 1989-1991. Annual reports. Available disposal capacity for solid waste in Illinois. Solid Waste Management Section, Springfield. Iverson, L.R., R.L. Oliver, D.P. Tucker, P.G. Risser, C.D. Burnett, and R.G. Rayburn. 1985. Forest resources of Illinois: An atlas and analysis of spatial and temporal trends. Special Publication 11, Illinois Natural History Survey, Champaign. Lashof, D.A., and E.L. Washburn. 1990. The state- house effect: State policies to cool the greenhouse. Natural Resource Defense Council, Washington, Dic Mansson, B., and J. McGlade. 1993. Ecology, thermo- dynamics, and H.T. Odum’s conjectures. Oecologia 93:582-596. Odum, H., and J. Arding. 1991. EMERGY analysis of shrimp mariculture in Ecuador. Report, Center for Wetlands, University of Florida, Gainesville. Prepared for Coastal Resources Center, University of Rhode Island, Narragansett. RESOURCE ANALYSIS Reinke, B. 1993. Solar input data for the state. Illinois State Water Survey, Champaign. Samson, I. 1992. Illinois mineral industry in 1990. Illinois State Geological Survey, Champaign. Smil, V. 1991. General energetics: Energy in the biosphere and civilization. Wiley, New York. Smith, W., and J. Stall. 1975. Coal and water resources for coal conversion in Illinois. Report 4. Illinois State Geological Survey, Champaign. Soil Conservation Service. 1982. Soil survey of Champaign County, Illinois. U.S. Department of Agriculture. Soil Conservation Service. 1989. Soil survey of Calhoun County, Illinois. U.S. Department of Agriculture. Soil Conservation Service. 1991. Soil survey of Mercer County, Illinois. U.S. Department of Agriculture. Soil Conservation Service. 1992. NRSA database. Champaign. Treworgy, C., and M. Bargh. 1982. Deep-minable coal resources of Illinois. Circular 527. Illinois State Geological Survey, Champaign. U.S. Department of Energy. 1992. State energy data report: Consumption estimates 1960 -1990. Energy Information Administration, Washington, D.C. U.S. Department of Transportation. 1980-1991. Annual publications. Highway statistics. Federal Highway Administration, Washington D.C. USEPA. 1991. National air pollution estimates, 1940— 1989. Report EPA-45014-91-004. U.S. Environ- mental Protection Agency, Washington, D.C. Woodwell, G., and C. Hall. 1973. The ecological effects of energy: a basis for policy in regional planning. Jn M. Goldberg, ed. Energy, environ- ment, and planning—the Long Island Sound region. Proceedings of a conference, Brookhaven National Laboratory, August 1971. World Resource Institute. 1992. World resources 1992-93: A guide to the global environment. World Resource Institute, Washington, D.C. World Resource Institute. 1993. Information please environmental almanac. World Resource Institute, New York. 242 50272-101 REPORT DOCUMENTATION |}. REPORT No. 3. Recipient's Accession No. Preemne-cr-syoss) | 4. Title and Subtitle 5. Report Date The Changing Illinois Environment: Critical Trends Technical Report of the Critical Trends Assessment Project ‘6 Volume 3: Ecological Resources 7. Author(s) Illinois Natural History Surve 9. Performing Organization Name and Address Illinois Department of Energy and Natural Resources Illinois Natural History Survey Division 8. Performing Organization Rept. No. y, 10. Project/Task/Work Unit No. 11. Contract(C) or Grant(G) No. (Cc) (G) 12. Sponsoring Organization Name and Address Illinois Department of Energy and Natural Resources 325 West Adams Street Sprinafield, IL €2704-1892 13. Type of Report & Period Covered 16. Abstract (Limit: 200 words) Illinois ecosystems are greatly affected by human activity. These effects are generally increasing, in spite of many improvements and a reduction in pollution sources. Often the largest impact is land use. Six ecosystem types are covered, and some general resource issues are analyzed. Prairies: Tallgrass prairie, which originally covered 60% of Illinois, is 99.99% gone. Forests: Once diminished by development, forests are coming back. Although many species use Illinois forests, biodiversity is threatened by forest fragmentation and introduced species. Agricultural Lands: Recent changes in farm practices have apparently lessened effects of agriculture on other ecosystems. Wetlands: About one-eighth of Illinois' original wetlands remain; wetlands are repositories of many threatened and endangered species. Lakes and Impoundments: Introduced species and fishing pressure have greatly affected Lake Michigan Fish, and impoundments are seriously affected by sedimentation and eutrophication. Flowing \laters: Past declines in water quality led to extirpation or near-extirpation of many species. Conditions have improved, but sedimentation and chemicals continue to cause problems. Resource Analysis: Coal is the only energy source produced in Illinois for which reserves far exceed current consumption rates. The ratio of fossil fuel use to solar radiation in Illinois is 600 times the world average. 17. Document Analysis a. Descriptors b. Identifiers/Open-Ended Terms c. COSATI Field/Group 1: Waepity Meare 1 vastriction on distribution. 19. Security Class (This Report) a Available at Illinois Depository Libraries or | Unclassified oe eS a from National Technical. Information Service, ai Security Cines (This Page) me Sabkase pringtield A 616 Unclassified (See ANSI-Z39.18) Bie inailiedcne’ an Naveren OPTIONAL FORM 272 (4-77) (Formerly NTIS—35) Department of Commerce Mansons FOE pa eee aes : Kenkegibg Py Pana * Sf sheritaeaaiione instead jena on tT patgaal REVEL Sens ‘APIO. aoshona Sivemeabeeh easy: wt: eh toe Sra], 123 wns Siraetens IK _ yok pa), Bae war Sais) enh aiehdereenallenetieaiibend a Sarre tee wee gcd Surrey. Comnpaan, mr he ee LM: a Va General ede sel tho «sy Fe- Yy af Melaodiyis ee Saenhy BE hi cm. Wiley, ew Por kr. : i.e. Sot owt Sill, 1975. Cutt and weer ope ferutsh: bas yetaa3 to themiy aad] CERIN VARI ES 4 Httanis, Ropes 4, liens noferyed vere Sesh Sig oh Ts Sta Gentaghl Sin yey, Champaign, Sul Coan sila pga Seren. (ORS Salts aia) Very 20 malariae es EI Seiad ea >) aaa cae nt a See ¥7% + ‘i wtih dw oad soit f Sri tsht binb! yore 2 Sra 9 ot t gaa732. P i } get nciaevaugon Her wen 199, Sosl suryey & aia tli . US Dagdienent af | ; Agtonlane ‘Seat apts a bre 7. 3 Lat haerahion 5° ivok, 191, Mam Runvty 4 ater aN Ceueiy, Hines. us Derrinien of Au oulire a i y sake peeve? Seay. 132. it WA. atest on A Aaa om oe Nyewetpy, (26d 26d At. iMag: OW2. Scan minal Si cud AeA 4 tre Wud vd botoetts fadice 6 aateae i WT Het 434 6 bas etnemsvoront ynam Y6 Sitge Rt -Oxiemwiont Yt fersnae! Sack Cra Re-oeMMRa Ne te semactYtogs xt2 .geu bnel gt toaqet s2anret say | barra vou Plan hpae 13 ie a "8erm({sT :zatrtsv? hasylens. eye eaugel Sov gxB esaané tzid veh itethids = dudintatete nO ietesiol shop tee, OS x? ob ster TT R62 > taisw Wh, earn FebeeDha z.. bonatsswiy et yJizisvibatd .etzona? efontiT! seu 2317998 a eon 496d. 0 sda At Bepriadosaeogh: 2 aeiwrtustips .20hseqa beoub tystnacpeytt 23" ‘[sebne tye ee bre Swdluthies to efastle beadeeal dseaanee gyen e2s0hjjem 4 nl O 29t viachsagee brides binant dew Sint Be elmelisw féntyteo 'ehont (fl Yo lao. be “| brs leg cont eg iteusads! Leases barepahons bis bevsyesist Ynen jvfeuolys2 8 cn ahs pits ie emote 9x5.) batset’e xiteey ovad sruezerg ; be Notisothaeigs SNe mottétisetber ¥d bs ‘5 vy St muTO not tsqr! Seatiien Ne ol Senrkyxs oF bal ae _ ie att % putt 2u0s 2! wa teqentiy ‘hee NOP ssInantbee Sud" yt fl soy Fipea ttl at om ubirve arigy prene \ Tho: eat 2 het tarp aR, Tae Agiee fou? (reset ae orter aiT eete7 Norse ahayt Ba Mi #iatd, H Bt STERN F O0F u jer ft : ‘a Crosentings af» .oniht's ote, Bani iaven -oyereve bitow odo eacat a nde Dhua: 2s sf L shea tH okey S os Bk a — es ee eee ape ees. es me Wintd Resource laviote, 197 i nied * wih» i ° 097-9314 wuade bas thes te ‘el qe) ere! World tesounce taeamete WW withers a World Reare code strive, {99% (piece (ata a! enviviriaenia ainhwar, Wie Cieees Artech Yatha r ‘ aie ine y romat f y ‘ ll | * « ' - $f j a S. aeaRwy St GOON mT ute tenn rm nina bowie se are perder WEE ae! Besa nl en el siteantoab | perreye Terria i nota 899. ee a SH1ONU |) atno 2eraprdhd wieste Of «4 Le) sons 3 | Loge watt rena mir a ssatvtme ge) Ani Rh sel a d,beiitass tants 4 (t~2) BAR ae 4a ewig ee se veterans pat ra SBEAEITW ghuwewena’§) i me, ae tape Oe? bene ; ar a aan ee mica er x iets ees ae ‘G) q / ' av koe ee: zy . 7 wel ‘ ot y he , " Le ony ey Bld es 7 : ri | ‘ > > Mig ‘ > + A 7 8 | 4 ' one ‘ ; Peg a , , q \ , yy é * ly ’ ; ‘ . { é has birt “™ iy rT ‘ ‘ ri > ST y a d 7 A * e : ‘ thd #) 4 we AA Printed by the authority of the State of Illinois. Printed on recycled and recyclable paper. 3,750/June 1994