A 13.88: PISW-GTR- 381 ^plE^r^ United States i^iS Department of fi' Agriculture Forest Service Pacific Northwest Research Station General Technical Report PNW-GTR-381 October 1996 Disturbance and Forest Health in Oregon and Washington ,>.^»;Js,i^V ii-'^» liiJ^^Ji'^iiyH :■ fc^^ii'.tifei »y»i;:»»:t'itic; J ,^_ .x'^n,i^m-'' .a^^'.^*Mi .•*-'<»Q From the collection of the d m k o Prejinger '^ V ^Jjibrary San Francisco, California 2008 Technical Coordinators Sally Campbell is a pathologist, Pacific Northwest Region, PO Box 3623, Portland, OR 97208, and Leon Liegel is a research forester. Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR 97331 . QUEEN'^. 80ROL.'r.H PUBLIC I.I3P : DEC 2 7 1996 Depodtoiy i>ocument Disturbance and Forest Health in Oregon and Washington Technical Coordinators: Sally Campbell, USDA Forest Service, PNW Region Leon Liegel, USDA Forest Service, PNW Research Station Editor: Martha H. Brookes Natural RsMinrcea Joint publication of USDA Forest Service, Pacific Northwest Research Station and Pacific Northwest Region; Oregon State Department of Forestry; and Washington State Department of Natural Resources USDA Forest Service Pacific Northwest Research Station Portland, Oregon General Technical Report PNW-GTR-381 September 1996 ABSTRACT Campbell, Sally; Liegel, Leon, tech. coords. 1996. Disturbance and forest health in Oregon and Washington. Gen. Tech. Rep. PNW-GTR-381. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Pacific Northwest Region; Oregon Department of Forestry; Washington Department of Natural Resources. 105 p. The scope and intensity of disturbance by such agents as Are, insects, diseases, air pollution, and weather in Pacific North- west forests suggests that forest health has declined in recent years in many areas. The most significant disturbances and causes of tree mortality or decline in Oregon and Washington are presented and illustrated. We discuss the interrelations of disturbance with forest management activities and the effect on native trees and suggest some solutions for reducing the severity of disturbance. One chapter reports on a forest health monitoring pilot project. Keywords: Air pollution, diseases, disturbance, fire, forest health monitoring, insects, vegetation change, weather damage. SUMMARY Forest conditions in Oregon and Washington have been steadily changing for more than 100 years. Many disturbance patterns in forest stands no longer occur with the same frequency or intensity as in the past, and current patterns are often outside the natural range of variation. Much of the change in distur- bance regimes is due to fire suppression, harvesting practices in the last century, and increased urbanization, industry, and commerce. East of the Cascades • Outbreaks of defoliating insects, such as western spruce budworm and Douglas-fir tussock moth, are now larger, more intense, and more frequent than in the past. • Bark beetle mortality, associated with tree stress and over- stocked stands, is more prevalent. • Drought periods in the late 1980s and early 1990s, coupled with overstocking, contributed to increased susceptibility to insects, diseases, and fire. • Many root diseases and dwarf mistletoes are more widespread and destructive because of past harvest practices and the resulting changes in forest structure and tree species. • Fire is less frequent now but much more devastating on low- elevation, dry sites because of fuel buildup. West of the Cascades • Incidence and damage by native forest pathogens, particu- larly root diseases, have increased because of past forest management practices. • Periods of drought have contributed to susceptibility of trees to attacks by insects and pathogens. Southwest Oregon • The risk of fire and insect outbreaks has increased because of fire suppression, overstocked stands, and periods of drought. • Two exotic diseases, white pme blister rust and Port-Orford- cedar root disease, have significantly affected their host species and how they are managed. Urban Forests • Introductions of exotic pests have Increased greatly over the past century with increased commerce, travel, and new people moving to the Northwest. • Air pollution has increased in the Willamette Valley and Puget Sound areas with increased population and industry. Ozone and other pollutants can damage forests near — and even far from — pollutant sources. • Stresses on urban trees from air pollution, mechanical injury, and poor maintenance have increased in many cities and towns. • Fire, wind, insects, and diseases are hazards to the trees, people, and homes in the urban-forest interface. Forest Health Monitoring • National field protocols for the Forest Health Monitoring Program were tested west of the Cascade crest on 13 plots in Oregon and 12 plots in Washington in 1994 to establish baseline forest conditions in Douglas-flr habitats. • Operational forest health monitoring across all habitats in Oregon and Washington is scheduled to begin in 1997. • Other surveys and inventories are ongoing and continue to provide information on disturbance agents and forest conditions. Solutions for Forests • Thin stands to reduce competition, stress, and bark beetle East of the Cascades and in, susceptibility. Southwest Oregon , Harvest certain species such as lodgepole pine to create a mosaic of age classes across the landscape to prevent wide- spread outbreaks of bark beetles. • Design site-specific regeneration (natural or planted) to promote desired species composition and structure. • Keep in mind the effects that certain activities (such as thinning, harvest, or replanting with certain species) will have on root diseases and dwarf mistletoes. • Reduce forest-floor fuel to prevent destructive, stand replac- ing fires. Once fuels are reduced, prescribed fire will be safer and more effective. • Introduce prescribed fire that mimics natural, light, ground fires to maintain a light fuel load and remove fire-susceptible species, such as Douglas-fir and true fir, in low-elevation pine stands. • Use fire to regenerate species such as larch or quaking aspen that depend on fire or other disturbance to create appropriate seedbeds or stimulate root sprouting. Solutions for Forests West • In forested areas, shift stands from single to multiple species of the Cascades to reduce insect outbreaks and proliferation of diseases. Tradeoffs between maximizing timber production (traditionally with even-aged, single species plantations) and minimizing insect and disease damage must be examined. • Replant harvested or restored areas with seedlings grown from local seed sources or use natural regeneration. Severity of diseases such as Swiss needle cast is much less when trees are adapted to the site. • Maintain a mosaic or mix of species and age classes, prevent- ing the whole landscape from being dominated by uniform, highly susceptible stands. Solutions for Urban Forests • Reduce air pollution through a variety of strategies and new technology so that production of ozone and other pollutants that damage forests can be reduced or, at the very least, not increased. • Maintain programs to monitor and eradicate exotic pests and to prevent new introductions. • Plant and care for trees and other vegetation in urban areas. • Manage for hazards such as fire, decay, and root disease in urban-forest interfaces. The Future Citizens, forest owners, and resource managers must all be- come active to solve forest health problems in Oregon and Washington. Without cooperation and interaction among groups with diverse and opposing viewpoints, future needs and desires for products and services from regional forests will not be met. East of the Cascades, forest fuel reduction, thinning over- stocked stands, and changing species are needed to reduce the risks of uncontrollable, stand-replacing wildfires and widespread insect outbreaks. West of the Cascades, the continued introduction of exotic insects, diseases, and plants threaten the existence of native forests and, without continual vigilance, chances of establish- ment and spread are much greater. Air pollution, unless controlled and reduced in the Puget Sound area and the Willamette Valley, will affect increasing numbers of forest species, influencing their ability to grow and reproduce. On both sides of the Cascades, the incidence and severity of many native insects and diseases is closely linked to forest management. Awareness of the effects of different manage- ment activities on insects and diseases is essential to achieve desired forest conditions. Forest management, forest health monitoring, research, and public education are the tools needed to create and main- tain the forests that are so important to the people of Oregon and Washington. 1995 FOREST DISTURBANCE IN OREGON Root diseases & dwarf mistletoes continue to cause subtle but significant mortality and growth losses. Swiss needle cast on the coast IS a concern. Pollution from Portland and other urban areas has long-range effects on lichens and forest vegetation. Fire suppression contributes to overstocking, species changes, and increased risk of disturbance (fire, insects, diseases). Over- stocked stands experiencing bark beetle outbreaks. Western spruce budworm and tussock moth outbreaks collapse throughout state. New introductions of gypsy moth in 1995. Established exotics — balsam woolly adelgid, white pine blister rust, and Port-Orford-cedar root disease — continue to kill trees. Pandora moth outbreak collapses. Drought effects seen from the past decade of below-normal precipitation. Winter windstorms and flooding cause localized mortality. Drought in the late 1 980s and early 1990s contributes to moisture stress in over- stocked stands. Overstocked stands are experiencing bark beetle outbreaks and increased insect and fire susceptibility — aggravated by drought. Root disease and mistletoe losses increase where fire suppression and past harvest practices have increased hosts. Fir engraver and drought cause mortality in overstocked white fir stands. '*s>5F-!».3^^iW-'4^ rf|.^»^V 1995 FOREST DISTURBANCE IN WASHINGTON Hemlock looper outbreak collapses. Fire suppression contributes to overstocking, species changes, and Increased risk of disturbance. Overstocked stands experience bark beetle outbreaks. Loss of large, old trees. Decrease in Douglas-fir beetle ^ damage. ^ Western spruce budworm outbreak collapses In Okanogan. Pollution from Seattle and Puget Sound area has long-range effects on lichens and forest vegetation. New introductions of gypsy moth In 1 995. White pine blister rust affects whitebark pine at high elevations. Drought effects seen from past decade of below-normal precipitation. Root diseases & dwarf mistletoes continue to cause subtle but significant mortality and growth losses. Losses offset In many cases by Increased diversity and wildlife habitat. Root disease and mistletoe losses increase where fire suppression and past harvest practices have increased hosts. \ ft AUTHORS Chapter I Sally Campbell is a plant pathologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, P.O. Box 3623, Portland, OR 97208. Karen Ripley is an entomologist, Washington Department of Natural Resources, P.O. Box 47000, Olympia, WA 98504-7037. Ken Snell is a forester, U.S. Department of Agriculture, Forest Ser- vice, Pacific Northwest Region, P.O. Box 3623, Portland, OR 97208. Chapter 2 Andy Eglitis is an entomologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, Deschutes National Forest, 1645 Highway 20 East, Bend, OR 97701. Ellen Goheen is a plant pathologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, J. Herbert Stone Nursery, 2602 Old Stage Road, Central Point, OR 97529. Alan Kanaskie is a plant pathologist, Oregon State Department of Forestry, 2600 State Street, Salem, OR 97310. Dave Overhulser is an entomologist, Oregon State Department of Forestry, 2600 State Street, Salem, OR 97310. Chapter 3 Robert Backman is an entomologist, Washington Department of Natural Resources, P.O. Box 47000, Olympia, WA 98504-7037. Jerome Beatty is a plant pathologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, Columbia Gorge Ranger District, 31520 SE Woodard Road, Troutdale, OR 97060. Karen Ripley is an entomologist, Washington Department of Natural Resources. P.O. Box 47000, Olympia, WA 98504-7037. Kenhelm Russell is a plant pathologist, Washington Department of Natural Resources, P.O. Box 47000, Olympia, WA 98504-7037. Chapter 4 Alan Kanaskie is a plant pathologist, Oregon State Department of Forestry, 2600 State Street, Salem, OR 97310. Gene Milbrath is a plant pathologist, Oregon State Department of Agriculture, 635 Capitol Street NE, Salem, OR 97310-01 10. Paul Ries is an urban forester, Oregon State Department of Forestry, 2600 State Street, Salem, OR 97310. Chapter 5 Leon Liegel is a research forester, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 3200 Jefferson Way, Corvallis, OR 97331. Chapter 6 Sally Campbell is a plant pathologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Region, P.O. Box 3623, Portland, OR 97208. LeRoy Kline is an entomologist, Oregon State Department of Forestry, 2600 State Street, Salem, OR 97310. ACKNOWLEDGMENTS The following people are gratefully acknowledged for their invaluable contributions to this report. Layout and Design John Ivle and Delbert Thompson. Artwork, GIS Products, Photography, and Graphics Richard Busing, Tom Iraci, Shelley Hayden, Julie Johnson, Russel Mitchell, Mike O'Day, Gail Saunders, Craig Schmitt, Beverly Swanson. Aerial Survey, Climate, Fire, Insect, and Disease Information and Data Kathleen Johnson, Craig Schmitt, Don Scott, Keith Sprengel, Dick Stender, I>evi Strauss, George Taylor, Mike Ziolko. Typing and Revising Marian Ely and Virginia Hokkanen. Review of the Draft Report Bob Alverts, Bill Burkman, John Dale, Greg Filip, Susan Frankel, Andrew Gillespie, Fred Hall, Jim Hadfield, Robert Mangold, Barbara Ross, Darrell Ross, Susan Sater, Kathy Sheehan, Gordon Schmitt, Dewey Tate. CONTENTS CHAPTER I AN OVERVIEW of disturbance and forest HEALTH IN OREGON AND WASHINGTON 2 Introduction 2 Forest Health Defined 2 What Is at Stake 2 Assessing Forest Health 2 This Report 5 Sources of Information 5 Scientific References and Names 5 Changes In Forest Vegetation 6 Forest Succession 6 American Indian and Pioneer Influences 6 Logging and Tree Farming 7 Fire Suppression 8 Vegetation, Past and Present 8 Tree Mortality 1 1 Ecological Role of Mortality 1 1 Patterns of Mortality 1 1 Normal Mortality 12 Mortality Trends 12 Weather and Its Influence On Forests 13 Short-Term Weather Events 14 Long-Term Weather Changes 15 The Future 16 Exotic Pests 16 Problems With Exotics 16 Introduction of Exotic Pests 18 Reducing Introductions 19 Control and Eradication 19 Effects of Air Quality 19 Ozone 19 Lichens As Bioindicators 2 1 Acidity of Cloud Water 2 1 Monitoring Methods 21 Aerial Survey 2 1 Forest Inventory 22 Forest Heath Monitoring Plot Network 22 New Monitoring Technology 23 Risk Rating 23 CHAPTER 2 CHAPTER 3 DISTURBANCE AND FOREST HEALTH IN OREGON 24 Oregon Coast Range (M242A) and Western Cascades (M242B) 25 Ecology 25 All Species 25 Douglas-Fir 26 Various Species 29 Willamette Valley (242A) 30 Ecology 30 All Species 30 Oregon White Oak 32 Ponderosa Pine 32 Grand Fir 32 Hybrid Poplar 32 Eastern Cascades (M242C), Modoc Plateau (M26 1 G), and Blue Mountains (M332G) 33 Ecology 33 All Species 33 Mixed Conifers 35 Western Larch 37 Pines 37 Various Species 38 Southern Cascades (M26 1 D) and Klamath Mountains (M26IA) 39 Ecology 39 All Species 39 Port-Orford-Cedar 41 Five-Needle Pines 42 Mixed Conifers 43 DISTURBANCE AND FOREST HEALTH IN WASHINGTON 44 Washington Coast Range (M242A), Western Cascades (M242B),and Puget Trough (242A) 45 Ecology 45 All Species 46 Douglas-Fir 47 Hemlock 49 True Fir 50 Hardwoods 51 Eastern Cascades (M242C) and Okanogan Highlands (M333A) 53 CHAPTER 4 CHAPTER 5 CHAPTER 6 Ecology 53 Mixed Conifers 53 Pines 56 Aspen 58 DISTURBANCE AND URBAN FOREST HEALTH 60 Introduction 60 Disturbance Agents In Urban Settings 61 FOREST HEALTH MONITORING PILOT PROJECT IN OREGON AND WASHINGTON 66 General Site and Species Characteristics 67 Stand Characteristics 68 Understory Vegetation 68 Overstoiy Vegetation 68 Basal Area 69 Crown Ratings 69 Sapling Crown Vigor 70 Crown Density 70 Crown Dleback 71 Foliage Transparency 71 Damage 72 Full-Hectare Tally 73 Vegetation Structure 74 Lichen Communities 75 Songbird Habitat Indicator 76 Conclusions 77 THE FUTURE OF OREGON AND WASHINGTON FOREST HEALTH 78 East of the Cascades 79 West of the Cascades 81 Southwest Oregon 84 The Future 85 SELECTED REFERENCES 87 APPENDICES Appendix A — Common and Scientific Names 88 Appendix B — Counties In Oregon and Washington 19 Appendix C — 1995 Cooperative Aerial Survey Results 90 Appendix D — The National Forest Health Monitoring Program 101 CHAPTER I. AN OVERVIEW OF DISTURBANCE AND FOREST HEALTH IN OREGON AND WASHINGTON INTRODUCTION People, livestock, insects, diseases, snow, wind, fire, volcanic eruptions, earthquakes, and floods are constantly disrupting forests, slowing growth, and injuring or killing trees and other living components of the ecosystem. Disturbance is natural and necessary to for- est ecosystems; without it, forests could not regrow, recycle, and pass through successive stages from seedlings to old growth. But, when disturbance causes more continuous, severe, or widespread effects than people consider ac- ceptable or normal, the forest is described as "unhealthy." Forest Health Defined Forest health is a human concept, and people have dif- ferent views about what con- stitutes a healthy forest. As demands on forests change over time, so too will people's views of forest health. Cur- rently, two ideas are included in most definitions of forest health. • A healthy forest maintains its function, diversity, and resiliency; and • A healthy forest provides for human needs and desires, and looks the way people want it to look. What Is at Stake? More than 36% of the land area in Oregon and Washington is forested. Forest land in the two states includes more than 18 million acres of federal land (19 National Forests, 7 Indian Reservations, 4 National Parks, and almost 2.5 million acres managed by the Bureau of Land Management), more than 2.8 million acres of state land, and about 16 million acres of pri- vate industrial and nonindustrial forest land. The residents of Oregon and Washington de- pend on these forests for wood products, jobs, fisheries, recreation, scenery, school funding, clean water, and many other products and amenities. Much of what people value about the Pacific Northwest is tied to the forests. A healthy forest can renew itself vigorously across the landscape, recover from a wide range of disturbances, and retain its ecological resilience while meeting current and future needs of people for values, uses, products, and services. Adapted from: Forest Health Policy, USDA Forest Service. 1996. Assessing Forest Health Forest health is assessed by monitoring the condition of various parts of the forest. Certain traits, such as tree growth, crown condition, mor- tality, and lichen communi- ties, are good indicators of for- est health. The condition of these indicators is used to characterize the forest as healthy, unhealthy, or some- thing in between. Over time, monitoring shows changes in forest condition. Forest eco- systems age just as people do. Overview — 2 so some yearly change is natural. Unexpected and large changes, though, would be cause for concern and lead to further investigations. Detecting trends in forest condition and pre- dicting long-term consequences of significant changes are the two cornerstones of monitor- ing activities. By knowing how and when for- est conditions will change and what the ulti- mate consequence of these changes might be, scientists, managers, and citizens can work to- gether to plan alternative solutions and ac- tions. federal smd state agencies and private orga- nizations in Oregon and Washington monitor forest health by using a variety of surveys and inventories. ■ Doagtas-6r H Hcmlock-Silkaspnioe M Poodcroa pioc H Wesleniwlutcpiac I I Lodgepok pine ■ Latch H Hl-sprace D Redwood j I Pinyon-junipcr H Western hardwoods n Nocifbrest ■ Water Distribution of forest types in Oregon andWasliington. Source: Southern Forest Research Experimental Station, USDA Forest Service. Changes in Forested Land and Population in Oregon and Washington 1952 1995 ▲▲AAA ▲▲▲▲▲ A TTTTT TTTTT T . 5 million f_ I million " people Source: USDA Foreit Service, Was Kington Department of Natural Rejoi US Census Bureau Over the past 45 years, the popul- ation of Oregon andWasliington lias more than doubled (a 1 17% increase); forest land in the two states has shrunk only 16%. Overview — 3 Key (sections addressed in this report are in bold): Humid Temperate Domain Marine Division (240) Pacific Lowland Mixed Forest Province (242) Willamette Valley and Puget Trough Section(242A) Marine Regime Mountains (M240) Cascade Mixed Forest — Coniferous Forest — Alpine Meadow Province (M242) Oregon and Washington Coast Range Section (M242A) Western Cascades Section (M242B) Eastern Cascades Section (M242C) Mediterranean Regime Mountains (M260) Sierran Steppe — Mixed Forest — Coniferous Forest — Alpine Meadow Province (M26I) Klamath Mountains Section (M26I A) Southern Cascades Section (M26 1 D) Modoc Plateau Section (M26IG) Dry Domain Temperate Steppe Division (330) Great Plains — Palouse Dry Steppe Province (331) Palouse Prairie Section (33 1 A) Temperate Steppe Regime Mountains (M330) Middle Rocky Mountains Steppe — Open Woodland — Coniferous Forest — Alpine Meadow Province (M332) Blue Mountains Section (M332G) Northern Rocky Mountain Forest Steppe Coniferous Forest — Alpine Meadow Province (M333) Okanogan Highlands Section (M333A) Temperate Desert Division (340) Intermountain Semi-Desert Province (342) Northwestern Basin and Range Section (342B) Owyhee Uplands Section (342C) High Lava Plains Section (342H) Columbia Basin Section (3431) Ecological units in Oregon and Washington. Information in chapters 2 and 3 is arranged by ecological sections. Source.- Bailey et al. 1 994. Overview — 4 OREGON Non-Forest Forest 5«% Federal 4% State 2S ■ 100 to 140 @ 25 to 30 ■ 140 to 180 ■ 30 to 40 ^ Mof* tlian 180 tonroa: Ormgon Cfciiila ttfWe Precipitation patterns in Oregon and Washington. Extreme weather, such as wind storms (top), can kill trees outright. Some types of weather, such as hail (bottom), damage only parts of the tree but make it more susceptible to diseases and insects. Overview — 14 Conditions for winter wind damage often are restricted to a particular elevation, resulting in a band of damage called "red belt." Winter Wind Injury: The process of transporting water from roots to foliage is passive. Evaporation from the foliage, called transpiration, creates a deficiency of water at the top of the tree. Additional water molecules are drawn up along the trees' conductive tissues to replace molecules that leave the foliage. The resulting water column is like a drinking straw. Additional liquid is drawn upward to replace any liquid removed from the top. Injury can result to trees on warm, bright winter days. Pores on the foliage open to receive carbon dioxide from the air. Water begins to evaporate from the leaves and addi- tional water is drawn into the roots to replace it. Water moves slowly through cold soils, however. The foliage loses water faster than roots can acquire it, causing the foliage and upper branches to desiccate and die. Precipitation Willamette Valley S-year running average - 100-year average u^ O irt O Year The precipitation record for the Willamette Valley illustrates the cyclic pattern of moist and dry periods in the Pacific Northwest source. Oregon cumate Service, Oregon Stote University. southwest Oregon, the Blue Mountains, the Willamette Valley, and the Puget Sound cirea — experienced this drought. Outbreaks of some insects, related to increased moisture stress on trees particularly in overstocked stands, of- ten follow dry years. Over the last century in the Pacific Northwest, the most recent drought appears to be part of a cycle of wet and dry periods each lasting 10 to 30 years. This cli- mate pattern is within a currently accepted normal range of variability. Long-Term Weather Changes Long-term climate changes have and will continue to produce changes in forests in Or- egon and Washington. The environmental vari- able that limits forests most and defines for- est community gradients is available moisture during the dry summers. Long-term changes Overview — 15 in weather will also create changes in the in- tensity and frequency of natural disturbances, such as wildfire and wind storms, which in- fluence forest composition and structure. If the climate becomes significantly warmer and drier, forest communities may shift up slopes to higher, cooler, moister elevations; move to more northern latitudes; or move from southern to northern aspects. Because each plant species responds individually to the unique interactions of temperature, moisture, and site characteristics, some of the new com- munities are likely to be completely different assemblages from any community dominant today. Insects and diseases are likely to ex- pand or contract their ranges along with their hosts, but they may also change their behav- ior or habitat in unexpected ways. Because tree species are long lived relative to people, some of the forest changes caused by climatic fluctuations might not be obvious for decades or even centuries. Changes would be greatest in places where many species are already at their physiological limits (southwest Oregon, for example). An increase in insect and disease activity on relict populations, stressed by harsh site conditions, would be ex- pected. The Future A challenge facing climatologists, ecologists, and land managers is to improve understand- ing of how dominant weather patterns are likely to change — in both the short- and long- terms — and how these changes will affect for- ests. Although the climate has shifted in the past, determining if current trends in climate indicate a true climate shift or just a change within the normal range of variation is diffi- cult. If a climate change is predicted, forest managers will need answers to many ques- tions. How large will the change be? How soon is it expected to affect vegetation? How will plants, insects, and diseases respond? How will the industries and services that depend on forest communities be affected? Can forests be made more resilient to such changes? EXOTIC PESTS Trees have coevolved with their native pests for thousands of years. Forest health can be greatly affected when exotic pests are intro- duced and upset the balance. Exotic plants and animals — those intro- duced from places outside of their native range — can be harmful to native species. Many introduced organisms are beneficial, such as crop plants, ornamentals, game animals, and livestock; these organisms were deliberately in- troduced and are essential to United States commerce and society. In the Pacific North- west, the exotics that cause the most damage to forest trees are accidentally introduced in- sects and fungi. Introduced weeds are also de- structive, competing with native forest vegeta- tion for space, nutrients, and water. Problems With Exotics Without natural checks, the population of an introduced pest can grow rapidly and wreak havoc on the host organism. After a fungus disease — white pine blister rust — ^was intro- duced 86 years ago, western white pine has been significantly reduced in many Oregon and Washington forests where it once was common. The balsam woolly adelgid, an insect that was introduced to the Pacific Northwest in the 1930s, has damaged grand fir at low elevations in the Willamette Valley to such an extent that most are unable to reproduce. Exotic pests seriously affect Northwest for- ests. Damaged trees diminish the value of property and recreation experiences. Revenue is lost from recreation, forest products, and real estate. Quarantines to prevent pest spread disrupt and affect the costs of transporting local forest products. Control efforts (such as pesticide treatments or resistance breeding programs) are expensive, and additional money must be spent to replace killed or damaged trees. In Oregon and Washington, the cost of trapping, analysis, and eradication of gypsy moth from 1985 to 1995 exceeded $50 million. Most important, undesirable exotics change forest ecosystems. Potential effects range from slight decreases in native populations to per- Overview — 16 Spread of White Pine Blister Rust nil - Vi ....... ic. In the West (Pt. «rtil ^ 1 ^^^HH^^^^T^ 1 ^8^^^^^^ J \o 7 3 ^K^^^^ T^ / 1 B^^^^r -^''^^ ^M / ^^^^r __.^::^^^_\ *y **''^"7v^7^^^K ♦ >, .-^^'^pA: (ij /\ 1 ^— -;--, LA !♦♦/ 3^ ^hl ' ^ V \ \* 1^ MID / \ U ^Bl Kii ' ii:o ^ \^ \\ ^^1 Kll - 11S0 \ 1 r — ~] "31 . H40 Vyk 1 1 H41 - HS5 j.^,^ ^_3' \^ ♦ ■ ll'ttllon SItti \ r UiOA lereit Soilce, HiiHiera ttjl«V. 1 II. " "' "" \3 1 Voung men, employed by the Civilian Conservation Corps in the 1 930s, were set to work pulling Ribes bushes, the alternate host to the rust, in an attempt to eradicate the disease. Photo courtesy of the National Archives. Blister rust is aptly named, causing blister-like swellings and eruptions of yellow spores on branches and stems of five-needle pines. Once the entire circumference of the branch or trunk is infected, the portion above dies. White Pine Blister Rust: White pine blister rust was first found in the West in the summer of 1921. The disease was identified on eastern white pine seedlings, imported in 191 Ofrom France and then planted at Point Grey near Vancouver, British Columbia. By 1 922, rust infections had been discovered at many points along the Washington coast from the Columbia River north well into British Columbia. From that small begin- ning, this rust spread and infected all species of white pine found in the Pacific North- west, including western white pine, sugar pine, and whitebark pine. One early attempt at control was to eradicate the alternate host, currant or gooseberry plants fl^bes spp.). Many men were hired by the Civilian Conservation Corps (CCC) and Works Progress Administration (WPA) during the Great Depression years to pull and burn ribes bushes in Northwest forests. As recently as the early 1 950s, many students worked their way through college pulling ribes. The cost of this program was almost $100 million nationwide, with $62 million spent in the West. By 1 956, the rust had spread to most of the white pine forests in the United States, and control efforts turned from ribes eradication and quarantine to managing the disease, recognizing that it had now become a permanent part of many western for- ests. Management concentrated on developing pines resistant to the disease and trying to return white and sugar pines to their previous roles in forested ecosystems. Overview — 17 Introduced plants, such as the English ivy pictured here, can invade thousands of acres of forest before they are recognized as threats to native vegetation and w/7d//fe. manent alteration of biological communities. Although much attention is directed at intro- duced insects and diseases, the current and potential effect of introduced plant species on forests is huge. Not only do exotic plemts com- pete with native vegetation but they can also change the physical and biological environ- ment. Changes have been noted in moisture and nutrient status, microbial populations, and soil characteristics where exotic plants have become established. Organisms depen- dent on native plants and adapted to a par- ticular environment are also affected. Introduction of Exotic Pests Exotic pests usually travel to new areas as hitchhikers. Weed seeds, fungus spores, insect eggs, cocoons, or larvae arrive on plants, fur- Radiata pine wood chips in a Chilean ship hold. Regulations require inspection and sampling. Chemical or heat treatments are used to destroy pests associated with chips. niture, lawn mowers, logs, ships, cars, trail- ers, trains, and planes. Less frequently, they are blown or washed in by storms or other anomalous weather. Port-Orford-cedar root disease is thought to have arrived in the Pa- cific Northwest on infected ornamental plants in the 1920s; it then spread to both native Port- Orford-cedar in southwest Oregon and orna- mental Port-Orford-cedar throughout western Washington and Oregon. Increased travel, population expansion, and new trade with South America, Japan, China, and the former Soviet Union will contribute to increased introductions of plants and animals and increased chances that they will become established once they arrive. The benefits of economic growth for states such as Oregon and Washington resulting from trade with other countries has to be weighed against the risk of introducing new pests and the potential damage to forests. New regulations for imports of logs and lumber (and other unmanufactured wood items) have recently been implemented by the states and the Animal and Plant Health Inspection Service (APHIS), a branch of the U.S. Department of Agriculture, to reduce the risk of introducing forest pests into the United States. Overview — 1 8 Reducing Introductions Experts have suggested the fol- lowing measures to slow introduc- tions and prevent establishment of exotic pests. • Evaluate the potential for intro- ducing harmful pests with im- ports. • Increase inspection and quaran- tine efforts, especially as trans- porting and shipping technology changes. • Beware of accidentally introduc- ing new plant species into forest ecosystems. • Maintain detection programs so populations can be eradicated while they are still small and lo- calized. • Promote self-sufficiency in wood products so raw or unprocessed products do not need to be imported Air pollution is created in and around Portland, Oregon. The effects on vegetation are both short and long range because pollutants are carried from the city to nearby forests by wind and fog. Control and Eradication A pest becomes established once it is able to reproduce and maintain a population that survives from year to year. For exotic pests already established in Pacific Northwest for- ests, management strategies already in place are minimizing their effects: natural enemies such as predators and parasites are being re- leased to control populations of some exotic pests; resistance breeding programs are in place for white pine blister rust and Port- Orford-cedar root disease; and appropriate sil- viculture and pest management practices are applied in many areas to minimize exposure and spread. Unlike white pine blister rust or Port-Orford-cedar root disease, the European and Asian gypsy moths are not yet "estab- lished" in the Pacific Northwest. The moth populations are still too low to breed effectively and establish permanent populations. Eradi- cation efforts, such as pesticide treatments, are the most practical and effective at this preestablishment stage. In 1996, ten urban areas in the Northwest were treated for gypsy moth to prevent their establishment. EFFECTS OF AIR QUALITY Air pollution alters the chemical environment in which plants grow and affects the health of the forest. The population in Oregon and Washington is projected to increase into the future, and with more people come more cars and other services that cause air pollution. Washington Environment 2010, a recent study by the State of Washington and the Environmental Protec- tion Agency, projects that over the next 15 years, concentrations of the pollutants of great- est concern to natural resource managers — sulfur compounds, nitrogen compounds, and ozone — will not improve. In fact, ozone is ex- pected to increase by 30% in the Puget Sound area unless additional actions are taken. Air-quality work in Oregon and Washington forests has focused on the effects of ozone on vegetation, using lichens as air-quality bioindicators, evaluating the sensitivity of al- pine lakes to acid deposition, and determin- ing the acidity of cloud water. Ozone Ozone is formed on warm sunny days from hydrocarbons and nitrogen dioxide emitted by cars and trucks. Unlike stratospheric ozone. Overview — 19 Data dearly show t/iot ozone can adversely affect plant growth. Medium exposure is typical of ozone concentrations west of file Cascades. Source: Mavity et al. 1 995. Small Blackberry (Rubus parviflorus) 1.2 which protects life on Earth from the Sun's ul- traviolet rays, ozone in the troposphere — cre- ated from nitrogen oxides and volatile organic compounds by sunlight — is known to be un- healthy for people as well as plant life. Ozone is generally a problem to forest veg- etation only in the summer when plumes of pollutants flow downwind from major urban centers. Possible effects to vegetation include visible leaf injury, reduced photosynthetic ca- pacity, increased respiration, premature leaf death, reduced growth, and mortality. Ozone damages the most sensitive plants at concentrations lower than those that are harm- ful to people. The federal human-health stan- dard is 120 parts per billion (ppb). Lichens, a group of ozone-sensitive organisms, can be adversely affected at concentrations between 15 and 70 ppb. Effects on lichens are subtle but can ultimately be fatal. Entire lichen spe- cies can disappear from the landscape before Low Med High Ozone Exposure Level Passive ozone samples are taken on Mount Baker- Snoqualmie National Forest anyone notices. Recent studies of native her- baceous seedlings and ozone profiles com- monly found in the Pacific Northwest showed that typical ozone concentrations could cause damage and increase mortality of certain com- mon species. The Forest Service air program in Oregon and Washington and the Washington Depart- ment of Ecology currently measure ozone elec- tronically at Darrington, for the Glacier Peak Wilderness; Packwood Lake, for the Goat Rocks Wilderness; and Wishram in the Columbia River Gorge. Ozone is also being measured in wilderness areas by passive sampling, which uses inexpensive coated filters that chemically react at a known rate when exposed to differ- ent ozone concentrations. The next step is to establish plots of ozone-sensitive species in the highest ozone-exposure areas downwind of the Puget Sound and Portland urban areas as an- other monitoring method. Table I -I — Effects of declining air quality on lichen communities in the Pacific Northwest Air quality Effect on lichens pood Decline beginning becllne clearly visible The most sensitive lichens are present and healthy. Diversity and biomass of lichens is high. The most sensitive lichens are overgrown by other lichens or algae.Young individuals are absent. The most sensitive lichens are missing on conifers; other lichens are still abundant.The remaining lichens show high diversity and biomass. The most sensitive lichens are missing on hardwoods and conifers. Some of the remaining lichens show pollution effects. Diversity and biomass are intermediate to high. The most sensitive lichens are missing. All of the remaining lichens show pollution effects; diversity and biomass are intermediate. All lichens show strong pollution effects (high frequency of dwarfed, shrubby, compact growth forms; discoloration; fungal parasitism; and overproduction of dispersal propagules). Diversity and biomass are low to nonexistent. Overview — 20 Lichens are indicators of ozone and other pollutants. Lichen species disappear as pollution increases. Lichens and mosses are "poikilohydric" organisms, mean- ing they cannot maintain constant internal moisture the way most plants do. Daily drying and wetting cycles concentrate pollutants dissolved in rain, fog, or dust in tissues, independent of their sensitivity to air pollution. Lichens are thus excellent accumulators of sulfur, nitrogen, and metals, as well as more elusive but long-lived pollut- ants such as radioactivity and pesticides. Deposition patterns and "hot spots" of specific air pollutants can be mapped by analyzing their concentrations in samples of lichens and mosses. Lichens As Bioindicators Lichens (plants made up of a symbiotic as- sociation of alga and fungus) are sensitive to common pollutants in the Pacific Northwest: sulfur dioxide; oxidants such as ozone, acid rain, and fluorine; and some metals. Lichen species vary in their sensitivity to different pol- lutants. The presence or absence of different lichen species and the symptoms of pollution injury can help locate places with relatively high amounts of air pollution. Lichens are being inventoried and monitored extensively west of the Cascades. Initial analy- sis of monitoring results showed a curious ab- sence of leafy, nitrogen-fixing (air-pollution sensitive) lichens and an unexpected abun- dance of nitrogen-loving (pollution tolerant) li- chens in the Willamette Valley and the Colum- bia River gorge. Acidity of Cloud Water Water in clouds and fog can become acidic through interaction with atmospheric pollut- ants. Plants can absorb this acidic moisture through aboveground parts or through their roots after the moisture condenses and drips to the ground. Acidic cloud water can inhibit growth of sensitive species. Cloud water was monitored during the summer of 1991 at Stam- pede Pass and Granite Peak in the Alpine Lakes Wilderness, and during the summer of 1994 at Green Mountain in the Glacier Peak Wilder- ness. The minimum acidity of cloud water (pH 3.6) collected in 1991 for both sites was far more acidic than is necessary to Inhibit growth of some species. Unfortunately, the only In- formation currently available about effects on local species Is for conifer seedlings exposed to acidic fog under controlled conditions. More Information Is needed about the effects of acidic cloud water, as well as Injury thresh- olds to local species, before cause for concern is verified. MONITORING METHODS Changes in forest health can be detected by monitoring the condition of the forest. Several monitoring tools and methods are available for measuring the forest. Some have been used for years; others are new and have had only limited use. Many forest monitoring programs, such as forest Inventories, focus pri- marily on vegetation condition and change. Other parts of the environment — like weather, air quality, riparian habitat, fisheries, and wild- life— are measured in separate surveys or, more recently. In multiresource surveys. Aerial Survey The Forest Service and the States of Oregon and Washington began a cooperative aerial survey for insect damage in 1947; only National Forests and some state lands were surveyed. From the 1960s and continuing to the present, all forested lands In the two states, regardless of ownership, are surveyed by air. The states also fly special aerial surveys to track specific Overview — 2 1 The aerial survey maps areas of mortality and defoliatior) in Oregon and Washington forests each summer It is a cooper- ative effort by the Forest Service and the two state Forestry Departments. problems, such as bear damage in coastal Or- egon forests. Survey results are used by Forest Service and state resource managers to track the ap- proximate location and acreage of dying or damaged trees, to follow cycles of insect out- breaks, and to predict future damage. Land owners and man- agers use survey results to locate areas of insect or disease dam- age on their lands and to aid them in management decisions. Forest Inventory The Forest Service began to inventory the timber resource on federal, state, and private lands in the 1930s. In 1993, the Na- tional Forest Inventory in Oregon and Washington was changed to a multiresource survey, in which understory vegetation, forest floor woody material, wildlife habitat, and damage agents are also recorded. Forest inventories are ground- based (rather than aerial); they now consist of a series of system- atically located plots that are remeasured periodically, at 8- to 10-year intervals. Data from the plots are pooled to provide an es- timate of forest condition across any grouping, geographic or bio- logical. Forest Heath Monitoring Plot Networl< A network of forest health monitoring plots has been estab- lished on forested land of all ownerships across the United States. It consists of a series of ground plots on which variables, selected because scientists thought they would be good in- dicators of forest health, are measured. Although some vari- ables are the same as inventory measurements, others are quite different, such as tallying the number and diversity of lichens as indicators of air quality. Forest Health Monitoring is a national program, a partnership between several federal and state agencies. The program was started in the North- east in response to concerns about acid rain and Inventory crews visit permanent plots periodically to measure and record a variety of attributes such as tree size, understory vegetaiJon, woody material, and damage. Overview — 22 now includes 19 states. Oregon and Washington established and measured 25 plots in 1994 as a pilot project (see chapter 5 for results of the pilot project). The two states are scheduled to fully implement the program in 1997. The purpose of the Forest Health Monitoring program is to deter- mine the condition of forests over large areas, such as the West or the entire United States, and to de- tect changes in forest health at a broad scale. technology is the global positioning system (GPS). Using signals from several satellites, a portable GPS unit can calculate the precise lo- cation of a field plot. Currently, GPS units are taken to each forest inventory plot to record plot location. The location can then be entered on a GIS, and the inventory data for that plot can be related to other data for that particular location. New Monitoring Technology The launching of satellites and the explosive growth in computer technology have created many possible applications of new technolo- gies to forest monitoring. Commercially avail- able satellite imagery of forested land can be sorted and classified to identify species com- position, tree size, and canopy density for any given area of forest. Changes in vegetation can be detected by periodic comparisons of satel- lite images. In Oregon and Washington, satel- lite imagery of the National Forests is being purchased, classified, and used by the Forests. Geographic information systems (GIS) cire used extensively to store and retrieve aerial survey and other monitoring data. These sys- tems geographically reference each piece of in- formation and allow maps to be made that in- clude many layers of data. Another new Risl< Rating Monitoring susceptibility, or risk to distur- bance agents, is another way of monitoring for- est health. Using stand examination data from site visits, inventory data, aerial photography, and knowledge of forest conditions conducive to insects, disease, and fire, forested areas can be assigned a rating of current risk to a par- ticular disturbance agent. Over time, risk can change through "natural" maturing of the for- est, removal of some trees by a disturbance, or management activities such as thinning, prescribed fire, or harvest. Subsequent risk ratings using updated information can show these changes in risk. Several computer pro- grams for risk rating stands and watersheds are being used by National Forests to assist them in watershed analysis. Overview — 23 1995 FOREST DISTURBANCE IN OREGON Root diseases & dwarf mistletoes continue to cause subtle but significant mortality and growth losses. Swiss needle cast on the coast IS a concern. Pollution from Portland and other urban areas has long-range effects on lichens and forest vegetation. Fire suppression contributes to overstocking, species changes, and increased risk of disturbance (fire, insects, diseases). Over- stocked stands experiencing bark beetle outbreaks. Western spruce budworm and tussock moth outbreaks collapse throughout state. New introductions of gypsy moth in 1995. Established exotics — balsam woolly adelgid, white pine blister rust, and Port-Orford-cedar root disease — continue to kill trees. Pandora moth outbreak collapses. Drought effects seen from the past decade of below-normal precipitation. Winter windstorms and flooding cause localized mortality. Drought in the late 1 980s and early 1990s contributes to moisture stress In over- stocked stands. Overstocked stands are experiencing bark beetle outbreaks and increased insect and fire susceptibility — aggravated by drought. Root disease and mistletoe losses increase where fire suppression and past harvest practices have increased hosts. Fir engraver and drought cause mortality in overstocked white fir stands. Oregon — 24 CHAPTER 2. DISTURBANCE AND FOREST HEALTH IN OREGON OREGON COAST RANGE (M242A) AND WESTERN CASCADES (M242B) Ecology Steep, highly dissected mountain slopes dominate the topography of the Oregon Coast and western Cascade Ranges. Because of the marine influence, the coastal region has the warmest winters, coolest sum- mers, and greatest rainfall in Oregon. More than 100 inches of rain fall on the western slopes of these ranges; the drier eastern slopes of the Coast Range aver- age only 30 inches per year. Al- though July through September is very dry, fog contributes sig- nificant moisture along the coast and lower western slopes. Douglas-fir dominates forests of the Coast Range, extending from near sea level to about 4,000 feet. A pioneer species that reproduces after fire or other disturbances, its long life span allows it to persist during ex- tended stable periods and re- seed an area after a disturbance. Forests of the lower mountain slopes and the coastal fog belt are dominated by Sitka spruce, western hemlock, and west- ern redcedar. Other conifers in the Coast Range include grand fir, noble fir. Pacific yew, and lodgepole pine. Red alder is the most abundant and important deciduous species in coastal forests. Ivow and mid elevations of the western Cas- cades are dominated by Douglas-fir and west- ern hemlock, with western redcedar, bigleaf maple, and red edder common in drainage bot- toms. As elevation increases. Pacific silver fir, noble fir, subalpine fir, mountain hemlock, lodgepole pine, sugar pine, and Engelmann spruce increase in importance. Western white pine is a minor component, and whitebark pine is common along the crest. All Species Fires are infrequent but severe — ^In the western Cascades and the Coast Range, the interval between fires is generally long. When fires do occur, they are large and severe, kill- In the Oregon Coast Range, the most notable fire in recent history was the Tillamook bum, which destroyed 255,000 acres of forest land in the I 930s. Phow courtesy of the Oregon Historical Society (neg. 55029). Oregon — 25 ing most trees, such as in the Tillamook burn in the 1930s. These large fires are usually as- sociated with drought years and warm dry winds. Douglas-fir establishes well after in- tense fires, and many present-day Douglas-fir forests owe their beginnings to fire. The earli- est Douglas-fir plantations were established after a fire in the Coast Range around 1915. Wind and root disease cause wind- throw — ^Periodic severe windstorms, typically between October and March, can cause exten- sive windthrow. Root disease and stem decay are the most common biological factors pre- disposing trees to windthrow. If blown down trees are Douglas-fir, the Douglas-fir beetle is likely to attack and kill standing trees for 2 years after a windstorm. During an outbreak, the beetle typically kills about one live tree for every three or four that were windthrown. Mor- tality can be prevented if windthrown trees are salvaged or beetle repellents used. This inter- action of wind, root disease, and bark beetles creates canopy gaps, mixes soils during tree uprooting, and increases structural and bio- logical diversity in stands. The November 1995 windstorm in Oregon blew down trees on thousands of acres in the Coast and Cascade ranges. Mortality caused by Douglas-fir beetle is expected in areas where trees are not salvaged or protected. Douglas-Fir Douglas-Jir is plagued by root diseases — Laminated root rot, a native disease that af- fects many conifer species, is the most wide- spread and destructive disease of Douglas-fir in the Coast Range and western Cascades. Various surveys estimate that, on average, patches of lam^inated root rot occupy 3 to 5% of the Douglas-fir forest, but the disease is dis- tributed unevenly. Many stands in the north- ern Coast Range have more than 1 5% of their area occupied by root disease patches. Stem decay — too much or too little? As stands mature, decay organisms cause tree death or breakage, creating gaps in the canopy and providing rotten wood and hollow logs that are used by wildlife. Although there are benefits to wildlife, decay and stain can severely reduce timber value. In managed western Oregon stands, the harvest of old trees has decreased the average tree age and amount of decay, especially on private lands. A concern in areas with extensive young stands may now be the lack of decay and defect and its prob- able effect on wildlife and ecosystem processes. The amount of decay in trees depends on tree species (some species are more susceptible than others), and generally increases with the frequency of wounding, and the size and age of the wound. The amount of decay in a stand can be reduced by keeping rotations short and avoiding tree injury during management activities such as thinning. Decay can be increased by intentionally damaging trees, retaining defective trees, and inoculating trees with wood decay fungi The tradeoff between wood production and rotten wood for wildlife needs must be balanced through thoughtful long-range planning. Decay provides habitat for wildlife. ■:,n. >'- • '^ (1^ \ f-:i:^^r^.^{ :=>• - 7 \ " * • ' * - * «v ^ \¥^ Laminated root rot creates differerit-sized openings, as shown in this map of a 50-year-old Douglas-fir stand in the Forest Grove District, Oregon Department of Forestry. Source: Oregon Department of Forestry survey. Laminated root rot causes tree mortality and growth loss; it also predisposes trees to windthrow. Because the disease spreads from root to root and affects groups of trees, it com- monly creates canopy openings of various shapes and sizes. These openings allow light to penetrate to the understory, stimulating growth of herbs, shrubs, and tree species re- sistant to the disease. Trees killed by the dis- ease provide short-term snags and logs, which benefit many wildlife spe- cies. The increased diversity and ben- efits to wildlife partially offset the huge volumes of timber lost to this disease annually. Laminated root rot intensifies on a site when Douglas-fir or another highly susceptible species are planted in an infested area and the fungus, which survives for decades in buried roots, grows from infected roots onto the roots of the newly established tree. Some of the most severe damage is in the Coast Range, where diseased stands were burned or clearcut and planted with Douglas-fir. Current management emphasizes planting or retaining resistant or immune species and carefully designing silvicultural systems to prevent blowdown after thinning. Armillaria and black stain root dis- eases are far less abundant and dam- aging than laminated root rot but oc- casionally cause significant damage in young Douglas-fir plantations, par- ticularly those stressed by poor plant- ing or soil compaction. Both diseases are often found on the edges of lami- nated root rot patches. Swiss needle cast damages coastal Douglas-fir — Swiss needle cast is a native foliage disease of Dou- glas-fir throughout the Coast Range and western Cascades. It impairs the tree's ability to regulate water loss and causes premature loss of needles. Se- verely damaged trees grow poorly and may die. In most areas, the disease is of little conse- quence, causing premature shedding of 3- and 4-year-old needles. Since the early 1980s, however, thousands of acres of Douglas-fir plantations along the north coast have shown increasingly severe damage from this disease. In late winter and early spring, diseased plan- tations are noticeably yellow to brownish yel- Oregon — 27 Swiss needle cast has become increasingly severe during the last decade along the north Oregon coast. Diseased stands appear yellow and grow poorly (left) connpared to healdiy stands (right). Trees with Swiss needle cast may lose all but the current year's needles (left), in contrast to healthy branch (right). With so little foliage remaining for photosynthesis, tree growth declines and some trees die. low, in contrast to adjacent natural stands that are green and vigorous. Most plantations with severe symptoms are 10 to 25 years old and within 1 5 miles of the coast in the fog zone. Much of this area was previously dominated by hemlock, spruce, or western redcedar. Why this native disease has become so severe in this area remains unclear. The severity of symp- toms differs considerably among individuals in the Douglas-fir population, indicating that tolerance exists within the species. The current management recommendation for areas with moderate or severe damage is to favor species other than Dou- glas-fir whenever pos- sible. If Douglas-fir is planted, seed should be from parent trees that performed well in the coastal fog zone. Black bears injure and kill young Doug- las-fir — ^Black bears peel and eat the inner bark of young conifers, especially Douglas-fir, in spring when the inner bark is succulent and sugar con- tent high. When the en- tire circumference of the bole is peeled, the tree dies. Partial peeling can reduce tree growth and vigor, and provide an entry point for organisms that decay the valuable butt log. An Oregon De- partment of Forestry study of Coast Range bear damage found that for every tree with its entire circumference peeled, at least two other trees were partially peeled. Bear damage is common in Douglas-fir stands in the 16- to 25-year age class, often soon after the stands have been thinned. In these stands, bears prefer the most vigorous and largest diameter trees. Although bears damage trees throughout the Coast Range and Oregon — 28 Black bears peel and eat the sweet, succulent inner bark of young Douglas-fir in the spring. Bear-killed trees occur on about 40,000 acres annually in western Oregon. Bear Damage 1-25 26-50 51-75 76-99 100 Circumference peeled (percent) A survey of bear-damaged Douglas-fir in western Oregon found about one-third of the damaged trees were completely girdled and destined to die. Those girdled 76 to 99% are also likely to die. Source: Oregon Department of Forestry survey. western Cascades, damage intensity differs considerably from one area to another. Sur- veys since 1988 do not show a clear trend of increasing or decreasing damage. Damage in some areas is severe enough to warrant bear management programs. Various Species Western hemlock, Sitka spruce, and western white pine are affected by several insects and diseases — ^In northwest Oregon, western hemlock is host to annosus root dis- ease, hemlock dwarf mistletoe, and hemlock sawfly and looper. Sitka spruce weevil is an important pest of Sitka spruce regeneration in Hemlock dwarf mistletoe causes witches brooms, deforms branches, and decreases tree growth. Some wildlife species, such as the marbled murrelet, nest in branches deformed by dwarf mistletoe. Photo courtesy of Kim Nelson. coastal Oregon and has deterred foresters from regenerating spruce over much of its natural range. The range and abundance of western white pine, found mostly in the western Cas- cades, has been reduced by the introduced dis- ease white pine blister rust. But planting seed- lings bred for resistance to the disease, pruning young trees, and rating sites for hazard is en- suring the continued presence of western white pine in Northwest forests. Oregon — 29 WILLAMETTE VALLEY (242A) Ecology The forests of the Willamette Valley are stands, groves, or savannas of Douglas-fir and Oregon white oak, with scattered ponderosa pine. Western hemlock, grand fir, and west- ern redcedar grow on the wetter sites, as do bigleaf maple, black cottonwood, red alder, and Oregon ash. Most of the land lies between 50 and 1,000 feet in elevation, with a few hilltops on the eastern edge reaching 1,500 feet. The summers are hot and dry; annual precipita- tion ranges from 25 to 60 inches, most of it between October and June. Although the Willamette Valley is character- ized by a summer drought, weather records show that the severity of drought fluctuates in 10- to 20-year cycles. The mid 1980s to the early 1990s was generally drier than normal, and the next 10 to 20 years are predicted to be wetter than normal. All Species Lack of fire has caused species shifts in the Valley — Historically, fire was periodic in the Willamette Valley, either started naturally or set by people to maintain open areas. Fre- quent, light, ground fires maintained oak and pine stands because the large thick-barked trees tolerated fire better than did young oaks, grand fir, or Douglas-fir. In the last century, fire has been excluded, and many oak stands are now losing the competitive race with Doug- las-fir and other species. Without the return of fire, and with increased urbanization and agriculture, oak and pine stands will likely di- minish slowly in the Willamette Valley. Air pollution increases with increasing people— The population of the Willamette Val- ley has greatly increased over the past few de- cades, mostly in the Portland area. Future projections are for continued growth. Popula- tion growth will be accompanied by increased pollution from automobiles and light and heavy industry. Air pollution not only affects visibil- ity and human health, but also damages for- ests. Ozone is a pollutant that affects forests. Monitoring of both vegetation and air has shown that ozone concentrations in some ar- eas are high enough to cause plant damage. In the Willamette Valley, the number of lichen species, which are more sensitive to ozone than other plants, has decreased in some areas. The number and diversity of lichens, as well as the concentration of pollutants in lichen tissue, are being monitored to identify forested areas with ozone damage. Drought interacts with insects and dis- eases to damage conifers— The sudden ap- Drought Index Willamette Basin 2 Wet 1 0 Dt7-I -2 /^ Aa A K \A_/ ^-W^ u \^ y u •«.h*.r*«-r*»r^oooooocooooooooococoCT^ff^o^o^o^ o Year T In the Willamette Valley, wet and dry periods have Puctuated in 1 0- to 20-year cycles during the last century; 1 985 to 1994 was a period of drought Source: Surface Water Supply Index, Natural Resources Conservation Service. Oregon — 30 pearance in spring or eariy summer of dead lateral branches, dead tops, or entire dead trees (particularly Douglas-fir) can be alarm- ing. The primary cause of damage is water stress in the tree resulting from drought in the previous year or accumulated over several years. The water stress reduces the tree's abil- ity to defend itself against insects and patho- gens. Damaged trees are most common in urban areas on the fringe of forested areas, in overstocked stands, on compacted or disturbed soils, and on droughty or shallow soil types. Such damage was particularly noticeable dur- ing the late 1980s and early 1990s, a period of drought in the Willamette Valley. Similar observations were documented in the 1950s and the 1970s. ■fS 1 M -. ^ v4. **. i ♦ '^; k' % ^-^ n 1 i M A' Winter weather kills needles or tree tops — Winter drying of needles is common on Douglas-fir in the northern end of the Willamette Valley and in the Columbia Gorge, where dry, easterly winds and sunny weather cause water loss from needles to exceed water uptake by roots. Needles often dry out and fall from the tree in late winter and early spring. Although the damage is highly visible, the buds usually are not damaged and new growth re- sumes in spring. Low temperatures alone can kill needles, buds, twigs, or inner bark. Large trees, par- ticularly Douglas-fir and ponderosa pine, are often topkilled when low temperatures follow an unseasonably warm period. In the Novem- ber 1955 "deep freeze," and again to a lesser extent in the winter of 1985, widespread topkill was re- ported throughout the Willamette Valley. Mortality and other symptoms of low temperature injury often do not show up until one or two growing seasons after injury. Douglas-fir on droughty soils show typical symptoms of canker diseases after a very dry year. Symptoms of Moisture Stress. Trees respond to mois- ture stress in several ways. Under moderate stress, stem and root growth are reduced. As stress increases, trees become increasingly susceptible to certain insects and diseases, particularly canker diseases and twig beetles. Under severe drought, water content in the tree may drop so low that the entire tree or portions of it may die. Roots and the lower main trunk are the last to die, and often remain living even though aboveground parts are dead. Sudden low temperatures after a warm period in winter can kill the tops of large, exposed trees, especially Douglas-fir. Oregon — 3 1 Oregon white oak in completely stripped looper. Oregon White Oak Oregon white oak is threatened by develop- ment and fire exclu- sion— Oregon white oaks are one of the hallmarks of the Willamette Valley. They are ecologically im- portant as food for many wildlife species, espe- cially acorn woodpeckers and wild turkeys. In ad- dition to threats from ag- riculture, urbanization, and exclusion of fire, white oak is host to a plethora of insects and diseases; fortunately, few threaten its survival. The most visible and periodically damaging insect is the western oak looper, which defoli- ates trees over large areas. The present out- break has persisted for at least the last 5 years. Populations of this insect near the Dallas area have been so high during the past 4 years that the loopers have defoliated the tops of other hardwoods and Douglas-fir growing in asso- ciation with the oak. Armillaria root disease attacks Oregon white oak and is often associated with tree uproot- ing in urban areas. White oak is adapted to droughty summers, and summer irrigation in urban areas and parks seems to contribute to the development of armillaria root disease. Ponderosa Pine Native pine is disappearing from the Willamette Valley — ^Ponderosa pine was once abundant in the southern part of the Willamette Valley, but urbanization, logging, and fire exclusion have diminished its popu- lation to small scattered patches of trees, es- pecially in the northern part of the Valley. Natural regeneration has decreased, primarily because fire no longer creates seedbeds and removes competing understory vegetation. Genetically different from eastern Oregon ponderosa pine, Willamette Valley ponderosa late sun}mer can be of foliage by t/ie oak pine has few major pests when grown in the Valley. The ponderosa pine cone beetle attacks young cones and compromises natural regeneration. In larger trees, pine bark beetles can attack and kill moisture-stressed pines, particularly in drought years and in overstocked stands. Fo- liage diseases periodi- cally plague eastern Or- egon ponderosa pine planted west of the Cas- cade Range, especially in areas with persistent fog. Grand Fir Exotic insect damages grand Jir — The balsam woolly adelgid is a minute aphid-like insect that sucks sap from true fir trees and excretes a waxy "wool" that gives it its name. Introduced to the west coast early this century, this often overlooked pest has tremendous ef- fect on the growth and seed production of grand fir and likely is responsible for decreases in grand fir populations at low elevations in the Willamette Valley. Hybrid Poplar Poplar is host to a recently introduced foliage disease — Since 1980, commercial hy- brid poplar plantations have rapidly expanded in the northern Willamette Valley and along the Columbia River in Oregon and Washington. In 1 99 1 , two new species of melampsora leaf rust were reported from plantations near Scappoose, Oregon, and Woodland, Washing- ton. These particular rusts are considered the most economically important poplar leaf rusts in the world. As of 1995, one of these rusts has become established in the Pacific North- west, and the other (Eurasian poplar leaf rust) has not. Hybrid poplar clones resistant to these and other diseases are being developed continually. Oregon — 32 EASTERN CASCADES (M242C), MODOC PLATEAU (M26IG),AND BLUE MOUNTAINS (M332G) Ecology The Eastern Cascades and Modoc Pla- teau— ^This region comprises the eastern slopes of the Cascade Range and the dry vol- canic area at the southern end of the eastern Cascades. The eastern Cascades include sev- eral high volcanic peaks: Mount Hood, Mount Jefferson, and the Three Sisters, all with elevations over 10,000 feet. The mixed conifer forests of this area are very complex and variable in terms of species composition and structure. Typically, mixed conifer stands on moist sites are characterized by a sparse overstory of large ponderosa pines and Douglas-firs, and a dense understory com- posed primarily of true firs with fewer lodge- pole pine, occasional western larch, and west- ern white pine. Historically, these stands were predominantly pine, maintained by frequent, low-intensity ground fires. On dry sites, the structure and species com- position are simpler, normally consisting of only two species (white fir and ponderosa pine) in a distinctly two-storied arrangement with large pines in the overstory. The most com- mon pine species in this area are ponderosa and lodgepole. Each species covers a large area where it is the domingmt climax species. Less common are the five-needled pines, including western white and sugar pines. The Blue Mountains — Two major moun- tain ranges dominate the Blue Mountains re- gion, the Blue Mountains in the center and southwest and the Wallowa Mountains in the northeast. Wide, low valleys separate the mountain ranges and channel two major riv- ers, the John Day and the Grande Ronde. The eastern boundary of this region follows the Snake River through Hells Canyon, separat- ing Oregon and Idaho. Elevations range from 1,000 to 10.000 feet. Conifer forests are the dominant vegetation at middle elevations in the Blue Mountains. The forests range from spruce and fir at higher elevations to mixed conifers (grand fir, Douglas- fir, lodgepole pine, western larch, and ponder- osa pine) at mid elevations to ponderosa pine at lower elevations. Important hardwood spe- cies, such as black cottonwood, quaking as- pen, and willow, as well as many rare, endemic plant species, are concentrated in wetlands and riparian areas. Fire frequency once de- termined the composition of low and mid elevation forests in the Blue Mountains. De- cades of fire suppression and selective logging of serai conifers (such as ponderosa pine and larch) have created forests that are more sus- ceptible to disturbances from insects, diseases, and stand-replacing fires. All Species Drought, wind, and severe winters injure trees — Precipitation patterns are a key driv- ing force for determining the character of the forested vegetation on the east side of the Cas- cade Range and the Blue Mountains. Mois- ture, falling as rain or snow in the spring and fall, is abundant at upper elevations but de- creases rapidly with decreasing elevation. Summers are usually very dry throughout the area, especially at the lower elevations. Various weather-related events common to this area are important to forest health. Peri- odic droughts reduce the capacity of trees to protect themselves against insects such as bark beetles and defoliators; large-scale out- breaks often occur during dry periods. Dry years from the mid to late 1980s to the mid 1990s contributed to widespread tree mortal- Oregon — 33 Drought Index Grande Ronde, Powder, Burnt River Basin 2 Wet I 0 Dry-I -2 -3 N. Aa \ J \ \f \ K kt\ V \J\r ' V V r»«.r»vr^r^r^oooooooooooooocooocoo^o^o^CT»o^ o\ Year The last 10 to 12 years have been drier than average in eastern Oregon. In this drought index for the Blue Mountains, below zero represents drier than average years, and above zero is wetter than average. Source: SurfaceWater supply index. Natural Resources Conservation Service. ity on dry sites, particularly where stands were overstocked. Windstorms can cause stem breakage and windthrow, which increases stem decay in wounded trees and leads to bark beetle buildup in windthrown trees. In the Blue Mountains, severe winter storms often cause extensive snow breakage or windthrow in localized areas. Floods and ice jams fre- quently damage trees growing in riparian zones or on flood plains. Fire siq}pression charges forests — ^Natural fire has played an important role in mixed co- nifer and ponderosa pine forests. In the low- elevation mixed pine and fir forests, frequent low-intensity fires maintained stands at low tree densities. At higher elevations, fires were less frequent but of higher intensity, often lead- ing to removal of the entire stand. With the suppression of the low-intensity ground fires, stands have become extremely dense and now contain a large proportion of species such as true firs that are particularly susceptible to insects, diseases, and stand-replacing fires. Dwarf mistletoe is more severe where fire is suppressed — Many conifer species east of the Cascades are infected by dwarf mistletoes, which are plant parasites. Before the 1900s, fires were frequent and reduced or eliminated dwarf mistletoe in many stands in the eastern Cascades and the Blue Mountains. For most tree species, fire suppression in the past cen- tury has resulted in more severe mistletoe in- fections, particularly when stands are unmanaged. In the eastern Cascades and on the Modoc Plateau, Douglas-fir dwarf mistletoe is the most pervasive and damaging. Western larch also has high rates of mistletoe infection, despite the distances between host trees on stands. True firs, too, are affected by a dwarf mistle- toe, but the effects on tree health are far less intense than in Douglas-fir and western larch. The combination of mistletoe infection and an opportunistic canker fungus often kills branch tips and produces a conspicuous flagging in infected true firs. In the Blue Mountains, crown deterioration from dwarf mistletoe is the most important cause of western larch mortality in undis- More than 40% of the Douglas-fir in eastern Oregon are infected with dwarf mistletoe, which causes growth loss, topkill, and mortality. Note the prominent brooms on the tree in the fore- ground and the killed tops on the trees in the background. Oregon — 34 turbed areas, where 38 to 51% of the larch in a stand might be infected. Where larch stands are managed, the removal of badly infected trees can reduce the amount of infection and increase vigor of the whole stand. Dwarf mistletoe is also common in Douglas-fir, pon- derosa pine, and lodgepole pine. In pine, the most severe mistletoe infections tend to be in stands with a high proportion of pine and in- frequent-fire histories. Mixed Conifers Western spruce budworm population col- lapses in mixed conifer stands — The most significant and persistent defoliating insect in eastern Oregon has been the western spruce budworm. Between 1980 and 1992, more than 400,000 acres of host type in central Oregon and more than four million acres in the Blue Mountains were affected by the budworm. This outbreak coincided with a drought that af- fected most of eastern Oregon. Douglas-firs, grand firs, and white firs were repeatedly de- foliated at various intensities on the Ochoco, Deschutes, Wallowa- Whitman, Umatilla, and Malheur National Forests. Some of the defo- liation effects included topkill, tree mortality, reduced growth, elimination of cone crops, and reduced resistance to other agents of mortal- ity such as root diseases and bark beetles. In the most extreme cases (where the susceptible host type was most abundant), around 80% of the trees died. Spruce budworm popula- tions collapsed region wide in 1992, and very little current defoliation is evident in this part of Oregon. Bark beetles benefiting from crowding and drought — Several bark beetles have been important in eastern Oregon mixed conifer for- ests in the past decade: fir engraver, Douglas- fir beetle, and western pine beetle. These in- sects are opportunistic and usually benefit from stress on the host tree resulting from crowding, disease, defoliation, or drought. Old- growth set- aside stands, where management activities are restricted, suffered high tree mortality. An unprecedented amount of fuels from insect-killed trees has accumulated dur- ing the last decade. The abundance of over- stocked, low vigor, mixed conifer stands in eastern Oregon makes a repeat of the massive tree mortality in the 1980s an eventual cer- tainty. One of the most conspicuous vegetation changes in southeastern Oregon was the massive white fir mortality in Lake and Kla- Western spruce budworm defoliation was apparent on almost all lands where the host species grew between 1 980 and 1 992. Source: Cooperative Aerial Survey, Oregon Deportment of Forestry and USDA Forest Service. Western Spruce Budworm 9 rt t re O [O 2 3 a> o "=> = E 2 ^ElL Year The number of acres affected by western spruce budworm in eastern Oregon peaked in 1 986. Source: Cooperative Aerial Survey, Oregon Department of Forestry and USDA Forest Service. Oregon — 35 Mortality from the fir engraver soared in 1 995; overstocking and drought are the underlying causes. Source: Cooperative Aerial Survey, Oregor) Departrr^ent of Forestry and USDA Forest Service. math counties. The cause is a fir engraver outbreak after several years of below-aver- age precipitation. Much of the mortality was in overstocked stands at elevations below 6,000 feet. Before fire-suppression pro- grams, most of these sites were dominated by ponder- osa pine stands. A similar pattern of white fir mortality is affecting areas of northern California. Because few of the dead trees have been sal- vaged, the potential for cata- strophic fire in Oregon re- mains high. The Douglas-fir beetle killed thousands of trees in recent years, especially in areas where the host trees sustained heavy budworm defoliation. After the spruce budworm outbreak, these bark beetles have attacked and killed many of the trees weakened by several years of defoliation and drought. Characteristically, Douglas- Armillaria root disease is the key disturbance agent in many mixed conifer stands. Trees weakened by soil compaction, drought, and overcrowding are very susceptible to armillaria. fir beetles select the largest trees in the stand and thus have profound effects on stand structure. These effects have been most notable in recent years on the Sisters Ranger District (Deschutes National Forest), the Warm Springs Indian Reservation in the eastern Cascades, and the Malheur, Umatilla, and Wallowa-Whitman National Forests in the Blue Mountains. Shifts in tree species cause increased root disease — Root diseases cause subtle, but persistent growth loss and mortality in mixed conifer stands. When disease pock- ets are small and scattered, they often in- crease the structural diversity and benefit wildlife and understory plants. Large root- disease pockets in areas designated for tim- ber management cause significant economic loss and increase fuel loading. Root disease has increased in mixed co- nifer stands as host species have increased. Fire exclusion has resulted in less pine and larch, species more resistant to root dis- eases, and greater numbers of the more sus- ceptible Douglas-fir and true fir. Partial cut- ting of mature trees in root disease areas, a common management practice, can intensify root disease problems. Root disease fungi colonize the roots and stumps of cut trees and then spread to live trees. Partial cutting also results in natural regeneration of sus- ceptible species in the dis- eased area. Disease centers will remain a problem in managed mixed conifer stands until the use of fire or other silvicultural treat- ments promote the regenera- tion of resistant serai species such as pine and larch. In- creases in the proportion of true fir and Douglas-fir in mixed conifer stands have led to increases in armillaria and annosus root diseases and laminated root rot. Oregon — 36 Ponderosa Pine Mortality ^ 60 at 3 E " 3 C ■5.0 > = E Volume ■ Trees ll L 200,000 o (0 Q. H 100.000 s Year Ponderosa pine losses from western and mountain pine beetle in eastern Oregon have been substantial, particularly in the early I 990s. Source: Cooperative Aerial Survey, Oregon Department of Forestry and USDA Forest Service. Old ponderosa pine is killed by pine beetles. West- ern and mountain pine beetles have been important mortality agents of ponderosa pine in pine and mixed conifer stands, in connection with drought and high stand densities resulting from the suppression of natural fires. On the Fremont National Forest, more than 14,000 large pines were killed in 1992, and another 18,000 in 1994. Throughout eastern Oregon, losses have been significant because old, yellow-barked pines are under- represented across the forested landscape and the "old- growth" character of mixed conifer stands is drastically altered by the loss of larger overstory trees. Western Larch The greatest threat to western larch is the lack of forest disturbance — ^Fire sup- pression and partial cutting maintain forest floor conditions that prevent larch from suc- cessfully regenerating. In the absence of dis- turbance, larch stands are gradually taken over by species more shade-tolerant than larch, such as grand fir and Douglas-fir. Only the re-introduction of fire or periodic mechanical disturbance can create the proper seedbed for larch. Furthermore, larch seed crops are usu- ally poor because of dwarf mistletoe infections, frost damage to conelets, and feeding by west- ern spruce budworm. Seed production is thus inadequate for either natural regeneration or nursery-grown seedlings. Pines Distribution of pine is affected by fire — ^Pon- derosa pine once covered large areas of the Blue Mountains and the east- ern Cascades that are now mixed conifer for- ests. Disturbance from fire played a crucial role in maintaining the domi- nance of ponderosa pine and stand health by re- ducing tree densities. Fire suppression in pine stands results in higher densities, reduced tree vigor, and greater sus- ceptibility to bark beetles, particularly in places where pine forests inter - grade with desert, like the southern flank of the Blue Mountains. Lodge- pole pine is an important serai species that colo- nizes disturbed sites in the grand fir zone in the Blue Mountains and frost prone areas in central Oregon. Although it is an aggressive colonizer, it can be replaced by shade-tolerant species such as grand fir in the absence of fire. In ar- eas dominated by lodgepole pine but with in- frequent fire, dwarf mistletoe has a significant effect on stand vigor. Mountain pine beetle is still evident in lodgepole pine — ^In eastern Oregon, the m,ost conspicuous incidence of bark beetle activity in pines has been mountain pine beetle in lodgepole pine. Although outbreaks of this species are infrequent — every 60 years — they always kill the largest trees in the stand and produce enormous quantities of fuel. In cen- Oregon — 37 Aspen groves that have been burned (left) can successfully regenerate by sprouting from roots of burned, killed trees. Aspen declines and other species encroach v^ere fire is suppressed (right). Artwork by Beverfy Swanson. Cottonwood and aspen groves are disappearing. Two shade-intolerant hardwoods, quaking aspen and black cottonwood, have declined as a result of cattle and sheep grazing, an increase in big game, exclusion of natural fires, and encroachrrvent of conifers. Regeneration of aspen requires fire to stimulate sprouting from roots and to eliminate competition from conifers. Cottonwood depends on flooding to control competing vegeta- tion and prepare suitable seed beds for regeneration; it also sprouts from roots after fire. These hardwoods are extremely important in riparian communities. They provide stream- side stability, shading, water temperature regulation, and wUdlife habitat. Although not abundant, quaking aspen is an important component of the eastern Oregon landscape. Over the past century, the extent of aspen stands has declined in central Oregon alone by about 50%. tral Oregon, an areawide infestation in the 1980s, covering more than 500,000 acres, killed virtually all trees more than 8 inches in diameter in pure stands of lodgepole. This out- break ended in 1989, although some areas, on about 50,000 acres along the Cascade Lakes Highway near Bend, are still experiencing sig- nificant mortality in lodgepole pine. In the Blue Mountains, the last major out- break of mountain pine beetle was in the 1970s, affecting almost one million acres. Al- though mountain pine beetle mortality has decreased since the 1970s outbreak, lodgepole stands will again stagnate and set the stage for another beetle outbreak unless active man- agement is initiated to control tree densities. Various Species Some insects and diseases are of local or diminishing importance. Root diseases (annosus, black stain, and armiUaria) are locally important on ponderosa pine in eastern Oregon. Engelmann spruce, important in riparian stands, is often infected by tomentosus root and butt rot, which makes it susceptible to windthrow and spruce beetle attacks after wind- storms. The Douglas-fir tussock moth outbreak that peaked in 1993, affecting 46,000 acres in the Blue Mountains, subsided in 1995. Simi- larly, the pandora moth outbreak on lodgepole and ponderosa pine in central Oregon peaked in 1994 and has collapsed in 1996. Oregon — 38 SOUTHERN CASCADES (M26ID) AND KLAMATH MOUNTAINS (M26IA) Ecology Southwestern Oregon is one of the most di- verse regions in the United States. Geology and soils are extremely varied. Elements of the California, north coast, and eastern Oregon flo- ras combine with many species indigenous only to the Klamath Mountain region. During periods of climate change, plants from as far south as Mexico and as far north as the Arctic established in the area and mixed with en- demic species. Plants and animals continue to migrate north and south along the Cascade/ Sierra and Coast ranges and east and west across links in the ranges. Species such as mountain mahogany, sagebrush, and quaking aspen reflect the area's importance as an east- west axis, and Pacific silver fir and Alaska yellow-cedar reflect north-south movement. Sierran pine and shrub species are also com- mon. The area has been the site of local de- velopment of ancient conifers including yew, cypress, and redwood. Forest vegetation in interior valleys of the Rogue and Umpqua rivers and lower elevations of the Cascade Range and the Siskiyou Moun- tains includes drought-tolerant conifers and hardwoods such as ponderosa and sugar pines, California black and Oregon white oaks, and Pacific madrone. Mid elevations include Douglas-fir, white fir, tanoak, and chinkapin. Higher elevations are dominated by true firs and mountain hemlock. The Siskiyou Moun- tains also contain large areas of soils that sup- port Jeffrey pine, Port-Orford-cedar, and unique associated flora. Southwestern Oregon has a mediterranean climate, with generally mild, wet winters and warm, dry summers. Most precipitation is from November to March. Summer thunder- storms are common. Annual precipitation ranges from slightly less than 20 inches in in- terior valleys to 120 inches at higher elevations. The late 1980s and early 1990s was a period of below-average rainfall. The area has the greatest temperature extremes in western Or- egon. In summer, it is often the warmest part of the state. Drought Index Rogue/Umpqua Basin Year Southwestern Oregon has experienced a drought over the past decade. This drought index graph shows years that are drier than average (below zero) and years that are wetter than average (above zero). Source: Surface Water Supply Index, Natural Resources Conservation Service. All Species Past and present fires irifluence vegeta- tion— Historically, fire has played a critical role in shaping vegetation. At low to mid elevations, frequent, low-intensity ground fires were once common. Fire frequencies ranged from 15 to 50 years in the Klamath Mountains. In inte- rior valleys, the fire-return interval was prob- Oregon — 39 ably 8 to 10 years, resulting in a pine-domi- nated forest with few snags and little woody material on the forest floor. In recent decades, the fire regime has shifted toward infrequent high-intensity, stand-replacing fires. Fire ex- clusion has resulted in substantial increases in stand densities and higher proportions of less fire-tolerant species. At high elevations, infrequent, low- to moderate-intensity ground fires were common historically. Now, high-in- tensity, stand-replacing fires are more com- mon. Root diseases have subtle but significant effects on growth and survival — Several native fungi cause root diseases in southwest- ern Oregon. Ofparticular importance are lami- nated root rot, armillaria, and black stain root diseases. Most root diseases are diseases of the site. Inoculum of laminated and armillaria root diseases may remain viable in the wood of infected roots for 20 to 50 years. They cause growth loss and mortality in individual trees. Across the landscape, root diseases produce changes in forest species composition and structural diversity. They create canopy open- ings, alter vegetative succession, provide snags for cavity nesters and their associates, and contribute woody material to the forest floor Root diseases (such as laminated root rot pictured above) are often overlooked because of the subtle nature of their effects; however, their long-term effect on growth and survival is much larger than that of virtually any other forest mortality agent and streams. Root diseases are managed by favoring resistant and immune species adapted to sites and by encouraging harvest practices that avoid reducing the vigor of individual trees. Dwarf mistletoes are more abundant now — ^Dwarf mistletoes are distributed widely in southwest Oregon, especially on the east side of the Siskiyous and in the Cascades. Lodgepole pine dwa^ mistletoe. %m-' Dwarf Mistletoes. Dwarf mistletoes are parasitic plants that infect conifer species. Small, sticky seeds are forcibly discharged from female dwarf mistletoe plants and land on conifer needles. They are washed down to the branches where they germinate, invade the tree tissue, and draw water and nutrients from the host plant. Infection is favored by multilayered canopies of single species. Most dwarf mistletoes are highly host specific, infecting only one or a few tree species. Their ejfects on their hosts include growth loss, topkill, distor- tion, mortality, and predisposition to infection and attack by other agents such as bark beetles or decay fungi Dwarf mistletoe brooms are often occu- pied by nesting birds and small mam- mals. Managing dwarf mistletoe to provide wildlife habitat without sacnfic- ing the vigor of the stand poses chal- lenges for land owners and managers. Mistletoes will continue to be aggres- sively managed where heavily infected trees pose threats to human safety or where timber values are of primary importance. Oregon — 40 They are common on Douglas-fir, white fir, lodgepole pine, Jeffrey pine, western hemlock, and mountain hemlock and less frequent on pon- derosa pine and other species. Trees infected with dwarf mistletoes have been removed during timber harvest and stand cleaning in some portions of the region. Many ar- eas, however, probably have more dwarf mistle- toe-infected trees now than they had before fire exclusion. Where ground fires were once frequent, higher proportions of in- fected trees were killed because ground fuels and large brooms carried fire into the crowns. In many areas with selective harvests, healthy trees were removed, leaving behind infected trees, or heavily infected trees were removed and infec- tion intensified in lightly infected trees when those Root Disease Pon-Orford = E 1 Volume "Trees 1 1 II 1 ...1 70,000 60,000 ; 50.000 I 40.000 : t 30.000 I 20.000 ; I. 10.000 0 Year Losses offve-needle pines has been greatest in southwestern Oregon between 1 988 and 1991. a period of severe drought Source: Cooperative Aerial Survey, Oregon Department of Forestry and USD A Forest Service. Mixed Conifers Bark beetle mortal- ity is highest on dry, overstocked sites — ^Ponderosa pine, Douglas- fir, and white fir mortality from bark beetles was particularly high in 1995, especially on dry, overstocked sites. Currently, drought and insects are replacing fire as primary regulators of site stocking. Such uncontrolled distur- bances have serious drawbacks. For example, large ponderosa pines tend to be the first trees killed by bark beetles; such large trees are of- ten important to meet management objectives. Extensive insect-caused tree mortality, par- ticularly in multilayered stands, can create massive fuel buildups, which ultimately can contribute to large-scale, severe wildfires. Landscape-scale assessment is becoming in- creasingly common for addressing drought-re- lated mortality issues. Density-management projects are planned or underway in many over- stocked stands. Treatments include thinning, prescribed burning, or a combination of the two. Treatment priorities are assigned by risk-rating systems that take into consideration stocking, elevation, proximity of insect activity, the urban- forest interface, and fire regimes. Bark beetle mortality in south- western Oregon has been high since the late 1 980s. The preva- lence of dense stands over ex- tensive areas and a succession of extremely dry years have pre- disposed trees to insect attack. Source: Cooperative Aerial Survey, Oregon Department of Forestry and USDA Forest Service. Locations of bark beetle mortality in all tree species on the Rogue River National Forest and Bureau of Land Management's Medford District in I 995. Source: Cooperative Aerial Survey, Oregon Department of Forestry and USDA Forest Service. Oregon — 43 1995 FOREST DISTURBANCE IN WASHINGTON Hemlock looper outbreak collapses. Fire suppression contributes to overstocking, species changes, and increased risk of disturbance. Overstocked stands experience bark beetle outbreaks. Loss of large, old trees. Decrease in Douglas-fir beetle ^ damage. 4 Western spruce budworm outbreak collapses in Okanogan. Q Pollution from Seattle and Puget Sound area has long-range effects on lichens and forest vegetation. New introductions of gypsy moth in 1995. White pine blister rust affects w^hitebark pine at high elevations. Drought effects seen from past decade of below-normal precipitation. Root diseases & dwarf mistletoes continue to cause subtle but significant mortality and growth losses. Losses offset in many cases by increased diversity and wildlife habitat. Root disease and mistletoe losses increase where fire suppression and past harvest practices have increased hosts. ,!■•'; J:v«t>:^iXi^r?.y^,;'^~::r^t>^iir-*?.!*;^'.^.-' Washington — 44 CHAPTER 3. DISTURBANCE AND FOREST HEALTH IN WASHINGTON WASHINGTON COAST RANGE (M242A),WESTERN CASCADES (M242B),AND PUGETTROUGH (242A) Ecology Washington Coast Range— The Washing- ton Coast Range extends from the Olympic Mountains in the north southwards into Or- egon. The Olympics, in the center of the Olym- pic Peninsula, are unusually high, with eleva- tions up to 8,000 feet; many of the major peaks have active glaciers. Most other peaks are be- low 4,000 feet. Flat, coastal lowlands are ex- tensive in some areas. Dunes and bogs are frequent along the coast, interspersed with headlands of more resistant rock. Douglas-fir, western hemlock. Pacific silver fir, and western redcedar predominate on the higher mountain slopes. Forests of the lower slopes and the coastal fog belt are dominated by Sitka spruce and western hemilock. Pre- cipitation is heaviest from November to April and averages 60 to 240 inches annually, some of the highest rainfall in the state. Severe win- ter storms cause landslides and windthrow. Stand-replacing fires burn at irregular inter- vals of 90 to 250 years. The Puget Trough— The Puget Trough is the northern extension of Oregon's Willamette Valley. In the north, glacial activity has shaped the land and influenced soil composition. Ele- vation ranges from sea level to 2,000 feet. The dominant vegetation in this region is western redcedar, western hemlock, and Douglas-fir. Riparian species include cottonwood, willow, red alder, and bigleaf maple. Precipitation av- erages less than in the Coast Range, from 25 to 60 inches, although intense winter storms caused flooding at frequent intervals before dams were built. Fires were commonly set by American Indi- ans, trappers, hunters, and settlers. Early fires created and maintained prairies that stretched — intermingled with forests — from Tacoma to the Columbia River. Today, many of the original prairies have converted to forests. The Western Cascades — The western Cas- cades region consists of steep mountain slopes, highly dissected by large rivers. Elevation ranges from near sea level at the Columbia River to higher than 14,000 feet at the peaks of the Cascade Range, although most of the region is between 2,000 and 7,000 feet. Low and mid elevations of the western Cascades are dominated by Douglas-fir and western hem- lock, with western redcedar, bigleaf maple, and red alder common in drainage bottoms. As elevation increases, mountain hemlock, sub- alpine fir. Pacific silver fir, noble fir, and En- gelmann spruce increase in abundance. West- ern white pine is a minor stand component, and whitebark pine is common along the crest. Precipitation ranges from 50 to 150 inches, falling as rain and snow during October to June. Summers are relatively dry. Fire peri- odicity is extremely variable, ranging from de- cades to centuries for major stand-replacing fires. Volcanos erupt periodically. Washington — 45 Pollution from the Puget Sound region can be seen at Red Mountain, near Mount Adams, more than 70 miles away. Days with little or no pollution (left) contrast with high pollution days (right). All Species Air pollution in Puget Sound has long- range effects — ^The population of western Washington is expected to increase in the fu- ture and, with it, the air pollution caused by automobiles and industries. Air pollution has What is a "hazard" tree? A hazard tree contains some form of structural defect, a peculiar location, or a combination of both, giving it a high possibility of failing and causing injury to people or property. To be consid- ered a hazard tree requires a valuable target — buildings, cars, or people — close to the tree. A rotten tree deep in the forest away from people is not a hazard because no target has been identified, but a rotten tree near a camp- site, road, or home is a hazard. many adverse effects on Northwest forests. Ozone, a pollutant created from nitrogen ox- ides and volatile organic compounds (both by- products of automobile emissions) and sun- light, damages a variety of plant species, with symptoms ranging from leaf spotting to de- creased growth to mortality. Some plants, such as lichens, are much more sensitive to ozone than others and can be used as ozone indicators. In western Washington, the number of lichen species, as well as the concentration of pollutants in lichen tissue, are being monitored to identify forested areas with ozone damage. Decayed trees are haz- ards in recreation sites — Trees with root disease and stem decays are potential haz- ards in recreation sites, par- ticularly in stands where the trees are old. Homes being built among the trees in the urban-forest interface are at particular risk from decayed trees, which can fail without warning, damage homes, and injure or kill people. Efforts are being made to teach homeowners, landscape plan- ners, highway department em- ployees, park staff members. Washington — 46 and other land managers to recognize and cor- rect tree hazards. Corrective measures may include tree removal, tree replacement, or pruning. Planning so human activity areas are away from hazard trees can reduce risk with- out altering the trees. Douglas-Fir Ejects of laminated root rot differ with site and use — Laminated root rot is wide- spread in southern British Columbia, Wash- ington, Oregon, western Montana, and north- em Idaho. It is believed to have co-evolved with its hosts, making it a natural part of many for- est ecosystems. It neither destroys huge ex- panses of forest nor threatens the existence of host species, but it does cause subtle, persis- tent growth loss and mortality. The effect on its primary host, Douglas-fir, varies with the use or setting of the trees. When disease pock- ets are small and scattered, they increase the structural diversity and benefit wildlife and un- derstory plants. Large root-disease pockets in areas designated for timber management cause significant economic loss. In settings such as parks, around homes, or along well-traveled roads, the disease can threaten life and prop- erty. Douglas-fir beetle increases after distur- bances— ^Douglas-fir beetle is the most impor- Douglas-fir Beetle Killed Trees 8 8 8 o o o o 1 I 1 Imlmm 1 1 85 86 87 88 89 90 9! 92 93 94 95 Year Douglas-fir beetle attacks large groups of Douglas-fir only when large amounts of food (downed trees) becomes available after windstorms, fires, or logging. Douglas-fir beetle activity decreased in 1 995 in western Washington, source: Cooperative Aenal Survey, Washington Department of Natural Resources and USDA Forest Service. tant bark beetle of Douglas-fir. In western Washington, it attacks Douglas-fir 60 years old or older; low populations are always present. When populations are low, the beetle is rela- tively nonaggressive, attacking recently killed (windthrown, snow-broken) or dying (root-rot infected, defoliated, drought-stricken, fire- damaged, wounded) trees. When many fresh logs become available in a short period, from such events as windthrow, fires, or logging, the beetles can reproduce in them and quickly reach outbreak populations. They can then attack and kill healthy trees. Relatively pure stands of Douglas-fir, 120 years old or older, of low vigor from competition, drought, or dis- eases, are most at risk from beetle attack. The 1995 cooperative aerial insect detection survey reported more than 2,000 trees killed by Douglas-fir beetle on about 3,000 acres in western Washington, a three-fold decrease from 1994. Because aerial surveyors detect tree condition based on changes in foliage color, trees that quickly lose their needles may not be recorded. Fog and off-site trees create an ideal environment for needle disease — Swiss needle cast is a native disease of Douglas-fir Washington — 47 "Bubble caps" containing MCH protect high-value trees from Douglas-fir beetle attack. How to minimize Douglas-fir beetle damage. Losses from Douglas-fir beetle may be reduced by promptly removing fresh logs from the forest. Exten- sive winter windthrow must be removed before beetles emerge. Any standing, live trees that were killed during the initial attack on logs should be removed as well. Trees that have been dead a year or more are generally no longer suitable habitat and need not be removed. Salvage operations need to be carefully planned and executed in a timely manner. Tree tops and large limbs need to be piled or scattered away from standing green trees to prevent emerging beetles from attacking healthy trees. The experimental phero- mone MCH, a Douglas-fir beetle anti-aggregant, could be used in the future in selected areas such as camp- grounds to protect trees from attack. throughout the Coast Range and western Cas- cades. In most areas, the disease is of little consequence, causing premature shedding of 3- and 4-year-old needles. Since the early 1980s, however, thousands of acres of Doug- las-fir plantations in western Washington have shown increasingly severe damage from this disease. In late winter and early spring, dis- eased plantations appear noticeably yellow to brownish yellow, in contrast to the adjacent. green and vigorous natural stands. Individual tree symptoms include severe chlorosis (yel- lowing), poor retention of needles, and reduced height and diameter growth. With little foli- age remaining for photosynthesis, tree growth declines, and some trees eventually die. The severity of symptoms differs considerably among individuals in the Douglas-fir popula- tion, indicating that tolerance to infection ex- ists in the species. n ^ ^^ Jfl^ , % ^ 1 "^ fe ■ r f Trees with Swiss needle cast often retain only one or two year's worth of needles compared to iJie four year's retained by healthy Douglas-fr (left). Diseased needles turn yellow and are easily shed (right). Washington — 48 Most plantations with severe symptoms are 10 to 25 years old and within 15 miles of the coast in an area prone to fog; before they were logged, these areas were dominated by hem- lock, spruce, and cedar. Swiss needle cast also infects plantations farther inland on the west side, typically where large plantings of Doug- las-fir occupy valleys surrounded by hills or mountains, where poor air drainage contrib- utes to the buildup of the fungus. These in- land plantations usually recover from heavy infection after 2 to 5 years, so changing them to species other than Douglas-fir is unneces- sary. The disease can be controlled with fun- gicides, but treatment in forest plantations is uncommon and not usually advised. Hemlock Two dwarf mistletoes infect hemlock trees — ^Western hemlock dwarf mistletoe is the most widespread dwarf mistletoe in west- ern Washington. Taxonomically, this para- sitic plant is separated into two subspecies that look almost identical but are specific to the two species of hemlock found in west- ern Washington: western hemlock and mountain hemlock. Each subspecies also infects a variety of true firs, spruces, and pines to a much lesser extent than hemlock. Western hemlock dwarf mistletoe is a seri- ous parasite along the Pacific coast from California north to Glacier Bay, Alaska. As with all dwarf mistletoes, infected trees show increased raiortality, reduced growth, lower fiber quality, and an increased susceptibil- ity to other disturbance agents. Heavily in- fected trees show growth reduction in both volume (40%) and height (84%) compared to uninfected or lightly infected trees. Mountain hemlock dwarf mistletoe is com- mon on mountain hemlock and true firs in northern California and the Oregon Cas- cades but, until recently, was thought to be restricted to small populations in two areas in Washington — north of Mount Baker and in the southern Olympic Mountains. Surveys conducted in 1995 in the Washington Cas- cades discovered at least three new, widely separated populations of this parasite. Hemlock infected by dwarf mistletoe is deformed, grows less, and is often killed. The large tree on the left is heavily infected with many mistletoe "brooms" (excessive branch growth caused by the infection). Western hemlock looper is a pest of old growth — The primary host for hemlock looper is western hemlock, although it will feed on other conifer species and understory shrubs found in association with western hemlock. Heavy, repeated defoliation during an outbreak can result in tree mortality. Western hemlock looper is generally very successful in extensive, old -growth, western hemlock forests. Early records of western hemlock looper outbreaks show vast amounts of timber killed in northwest Or- egon and southwest Washington. Outbreaks generally last about 3 years and are usually brought under control by the natural action of parasites, predators, and disease. Out- Washington— 49 Outbreaks of hemlock looper, an old-growth insect, may increase on federal lands as harvesting de- creases and more stands reach and exceed 100 years of age. Hemlock Looper 1995 1 1994 1993 1992 1 \ ( ) 10 20 30 40 50 60 Defoliation (thousands of acres) An outbreak of hemlock looper was detected in 1 993 and 1 994 in western Washington. The population collapsed in I 99 5. source: cooperative Aenat Survey.Washington Department of Natural Resources ar)d USDA Forest Service. breaks can also occur in vigorous 80- to 100- year-old stands. Today, the majority of stands that will sup- port large hemlock looper populations are in parks and reserves, mostly on federal lands in northwest Washington. Those lands with 80- to 100-year-old, vigorous western hemlock stands or multistory older, predominantly ma- ture timber are susceptible to hemlock looper outbreaks. The most recent defoliation from western hemlock looper was found on the Mount Baker-Snoqualmie National Forest. It was first noticed during the 1992 aerial survey. The outbreak peaked in 1993 with more than 49,000 acres defoliated. Populations collapsed sometime between 1994 and 1995. In 1995, extensive ground evaluations by forest health specialists did not detect any live insects. True Fir True fir stands continue to be changed by an introduced insect — The balsam woolly adelgid, an insect native to Europe, was first noticed in the Pacific Northwest in the 1930s on true firs in the Willamette Valley in Oregon. It gradually spread to true firs in the moun- tains. It slowly kills trees by infesting the twigs and branches, or kills them quickly by infest- ing the bole. It causes gouting (swelling) of branches and sometimes of the trunk. Dam- age and mortality are mostly confined to true fir stands on federal lands, but it could spread to all susceptible true fir stands. The Gifford Pinchot, Mount Baker-Snoqualmie, and Olym- pic National Forests report the highest mor- tality associated with balsam woolly adelgid. Balsam Woolly Adelgid 80,000 60,000 < "2 40 000 I 20,000 HiiiLiL Jl liU Year The number of acres with balsam woolly adelgid damage in western Washington since 1969. Source: Cooperative Aerial Survey, Washington Department of Natural Resources and USDA Forest Service. Washington — 50 Clark's nutcracker. Whitebark Pine Mortal! 7.000 ty 6.000 5.000 4.000 3.000 2.000 1.000 I Federal State Private Whitebark p'me mortality ir) Washington, source: Cooperative Aerial Survey, Was/i/ngton Department of Natural Resources ar\d USDA Forest Service. Wildlife habitat is affected by the decline of whitebark pine. White pine blister rust, fire exclusion, and mountain pine beetle continue to cause decline in whitebark pine. This tree is a prominent upper-subalpine species that is important as a source of food and habitat for many animals, including the grizzly bear, and is a keystone species in high-altitude ecosystems. Studies in 1991 and 1 992 in northwestern Montana showed the number of mature whitebark pines rapidly decreasing. Some whitebark pine stands in Glacier National Park have mortality rates of up to 90%. Recently, interest in the ejfects of blister rust on the survival of whitebark pine in the northwestern portion of its range, which includes Washington, has increased. A preliminary survey in Mount Rainier National Park completed in 1994 showed blister rust present in all whitebark stands inventoried. Twenty-seven percent of the plots within these stands had no infected trees, supporting existing evidence that whitebark pine exhibits a slight natural resistance to the rust. Because the seeds of the tree are spread by a bird, Clark's nutcracker, that caches them in the ground, the most effective management action to preserve this species would be to use fire to make clearings in the thick, true fir stands so the birds have a cleared place to hide the few seeds produced by naturally resistant trees. :ija£a Balsam woolly adelgid has caused dieback and death of hundreds of true fir since its introduc- tion from Europe in the / 930s. Photo courtesy ofRussel Mitchell. Hardwoods A decade of summer drought dam.ages hardwoods — Nearly 10 years of continual summer drought between 1987 and 1995 has been hard on hardwoods in western Washing- ton. The most commonly affected species are red alder and bigleaf maple, although conifers are affected as well. Damage has been wide- spread, found in the Puget Sound area, the Cascade foothills, and the San Juan and Puget Sound Islands. Moisture stress and resulting damage or death occurs between June and September. Sjmiptoms range from scattered, fading or red branches to whole tree mortal- ity. Often whole stands are affected, some los- ing up to 50% of the trees. This type of dam- age is common on soils that dry rapidly in the Washington — 5 1 130 120 I 10 100 90 80 70 60 50 Precipitation NE Washington - — Total annual — 1 00-year average k /\ / A iy\ JTl V\^ \/ \ \1 \i * V y V v Y ^ Year Annual predpitation in the western Giscades was lower ^an average most of the years between 1 985 and I "yj. Source: Washington Department of Natural Resources. summer, such as shallow, hardpan or deep, gravelly soils. Diseases or outbreaks of insects, such as forest tent caterpillar on red al- der in 1987, often are associated with drought-stressed trees and accelerate tree death. By them- selves, many of these insects or diseases rarely cause mortality. Pacific dogwood is affected by fungus — Since the early 1970s, the native dogwood in western Washington has been in- fected by anthracnose, an intro- duced fungus disease of foliage and stems, that is often fatal af- ter a few years of infection. Many west-side dogwoods have suc- cumbed to the disease over the last 20 years. Some stands that had five dogwoods per acre 20 years ago may have none today. In other areas, the disease is not as common. Dogwood under- story in the eastern parts of the Columbia Gorge is generally healthy. Pacific madrone is injured by winter freezes — Winter freezes periodically damage tens of thousands of Pacific madrones through- out the Puget Sound region. Injury ranges from leaf browning to branch dieback and tree mortality. Trees with only leaf browning usu- ally recover. Madrone trees with winter freeze damage have been noted in 1972, 1985, and 1990. In the spring of 1996, madrones suf- fered nearly complete browning of the leaves. Sometimes the leaves at the tops of the trees were relatively undamaged. Often, affected trees were found adjacent to completely unin- jured trees. A weak parasitic fungus is sus- pected of colonizing the leaves after they were stressed by cold weather in January 1 996. Two leaf-mining insects were also found in the in- jured leaves and probably contributed to about one-third of the foliage damage. Emergence of normal-appearing 1996 leaves nearly hid the dead leaves. Whether the fungus can persist and spread to the new leaves is unknown. Leaf miners are one of several insects that attack Pacific maidrone. Washington — 52 EASTERN CASCADES (M242C) AND OKANOGAN HIGHLANDS (M333A) Ecology Eastern Cascades — The eastern Cascades region in Washington consists of the eastern slopes of the Cascade Range, which extends north into Canada and south into Oregon. Elevation ranges from near sea level at the Columbia River to more than 10,000 feet in the high mountain peaks. Precipitation patterns are the key force for determining vegetation in Annosus root disease fungus produces spores that infect stumps; the disease spreads from infected stumps to live trees by root- to-root contact. the eastern Cascades. At high elevations that receive more rain and snow, true fir, moun- tain hemlock, and Douglas-fir forests predomi- nate. At lower elevations, where moisture is sparse, ponderosa and lodgepole pines grow. Lodgepole pine is common on dry sites with poor soils. Local areas of whitebark pine, white pine, Engelmann spruce, and aspen are also found in the eastern Cascades. Fire periodic- ity is extremely variable. In the pine forests at lower elevations, fire occurred at 10- to 15-year intervals before fire suppression. Fire was less frequent at higher elevations. Okanogan Highlands — ^The Okanogan highlands are characterized by moderate slopes and broad, rounded summits. Several north-south rivers flow in this region, includ- ing the Columbia, Okanogan, Colville, and Pend Oreille Rivers. Vegetation patterns in the Okanogan highlands are strongly influenced by the east-west precipitation gradient. Pre- cipitation averages 30 to 60 inches per year, mostly as snow. Although ponderosa pine can be found growing in pure stands, it is more often found growing with other species in mixed stands, including Douglas-fir, grand fir, western larch, and lodgepole pine as major as- sociates. At higher elevations, Douglas-fir and true fir forests predominate. Historical fire re- gimes ranged from frequent, low- intensity fires to infrequent, high-intensity fires. Mixed Conifers Root diseases continue to increase in eastern Washing- ton— ^Laminated root rot is wide- spread throughout eastern Washington forests. The disease is increasingly common in the mixed conifer stands of north- eastern Washington, where Douglas-fir and grand fir are much more abundant in stands once dominated by ponderosa pine and western larch. Pine and larch tend to be more tolerant of the disease. Washington — 53 Annosus root disease has also increased in distribution and severity as a result of man- agement practices. Selective logging creates abundant stumps of ponderosa pine, grand fir, and subalpine fir that can be infected by air- borne spores. This increase in infection sites is compounded by high tree densities that in- crease the probability of tree-to-tree spread through root contact. Annosus root disease is particularly common in mixed stands of true fir and Douglas-fir of the southern Cascades near Yakima and Goldendale. Eastern Washington has areas with large amounts of schweinitzii root and butt rot in late serai and climax stands. The primary host is Douglas-fir, but western larch, spruce, and true fir are also infected. Infected trees rarely The fungus that causes armillaria root disease often produces edible mushrooms at the base of infected trees. Armillaria root disease. Incidence of armillaria root disease is also on the rise in the expanding Douglas-fir /grand fv timber type: mortality has increased because of stress fi-om overstocking. The disease is severe on Douglasfir and grand fir in northeastern Washington. Armillaria is sometimes extremely ag- gressive and attacks trees that do not appear to be under stress, such as ponderosa pine in pure pine stands southeast of Mount Adams. show outward signs of infection. The best way to detect the root rot is to find the large, rusty brown and often velvety, mushroom-like fruit- ing bodies on the ground near infected trees. Infected wood is stained red in Douglas-fir, and the advanced decay breaks down in reddish- brown cubes. As in other root diseases, infec- tion usually starts in root tips rather than through old fire scars or wounds, as was once thought. Trees with extensive butt decay may attract bark beetles and even armillaria root disease. Western spruce budworm damage is de- clining— Western spruce budworm is a com- mon defoliator of Douglas-fir and true fir in the Pacific Northwest, and outbreaks are frequent in mixed-conifer stands. Repeatedly defoliated trees show substantial radial-growth reduc- tion, £ind are often predisposed to attack by bark beetles. Effective fire prevention and sup- pression during this century have eliminated many major fires and nearly all surface fires. As a result, forests that have had no other dis- turbances, such as timber harvesting, have moved steadily toward climax and, conse- quently, an abundant and expanding source of the insect's favorite food — shade-tolerant, late-successional tree species. Western spruce budworm larvae prefer new foliage, but also feed on older foliage when new foliage is in short supply. Washington — 54 1992 1995 ^F~ •• %\ r ^1 \ ^' t^- \ L # * \ ^^^^^^__ \ The number of acres defoliated by western spruce budworm has declined sharply since 1992 (left) compared to 1995 (right), especially in the Okanogan area (northeast corner of the state). Source. Cooperative Aerial Survey, Washingtor) Department of Natural Resources ar)d USDA Forest Service. Budworm populations have declined signifi- cantly since 1992, when over 1.3 million acres showed some defoliation in eastern Washing- ton. The decline is attributed to a natural col- lapse of the insect population and increased precipitation. Areas of budworm defoliation increased slightly in 1995 compared with 1994. Dwarf mistletoe abundance is tied to host distribution, fire, and harvest — ^Dwarf mistletoes are found on all of the conifers in the mixed conifer forests of eastern Washing- ton. The distribution and frequency of dwarf mistletoe species closely follows the distribu- tion and frequency of their hosts. Before 1900, western larch dwarf mistletoe was the most widespread mistletoe in late serai stands. Western larch is less prevalent today but, be- cause of selective harvest which creates con- ditions favorable to spreading mistletoe, the remaining larch have a high incidence of dwarf mistletoe. In stands east of the Cascades, ponderosa and lodgepole pine dwarf mistletoes were his- torically more localized and less damaging than now because of the frequency and sanitizing effects of natural ground fires. Frequent underburning minimized the accumulation of fuels and the likelihood of stand-replacing fires. Many stands had some dwarf mistletoe infec- tion, but the severity was continually reduced by the frequent fires. In lodgepole pine, stand- replacing fires at intervals of 90 to 200 years eliminated mistletoe, along with the trees. In ponderosa pine stands, fire suppression has led to more widespread dwarf mistletoe. In ponderosa pine stands that have con- verted to true fir and Douglas-fir because of fire suppression, pine dwarf mistletoes have decreased and fir mistletoes have increased. Western larch dwarf mistletoe can be extremely damaging; mistletoe brooms on larch are brittle and break off, leaving infected trees with few branches. Washington — 55 At least 43% of the Douglas-fir stands east of the Cascades are estimated to be infected with dwarf mistletoe. Infections are more widely distributed and more severely damaging than ever before. Ecologically important features of the dwarf mistletoe are the wildlife food and habitat their flowers, seeds, and witches brooms provide. Brooms, which are caused by the reaction of the host tree to hormones produced by the parasite, are large masses of branches, twigs, and needles. Brooms are often retained on the tree after healthy branches are shed and pro- vide dense platforms, either close to the tree trunk or scattered about the crown. Brooms are used for nesting, roosting, and hiding cover by small mammals and birds, especially owls, hawks, and grouse. Drought, defoliation, and disease con- tribute to susceptibility to bark beetles — In eastern Washington, the Douglas-fir beetle normally breeds in felled, injured, or diseased trees. Drought, root diseases, and repeated years of defoliation by western spruce bud- worm increase the susceptibility of Douglas- fir to this beetle by reducing the tree's ability to resist attack. Mortality is widely scattered when beetle populations are low, but outbreak populations can kill apparently healthy trees over extensive areas. The fir engraver infests true firs in eastern Washington. It attacks pole-sized and mature trees, causing significant mortality during out- breaks. Outbreaks often occur during and af- ter periods of drought. Trees with root disease are especially susceptible to attack. Trees de- foliated by western spruce budworm also are likely to be attacked. The fir engraver com- monly breeds in slash and windthrown trees. Pines Mountain pine beetle causes mortality of many pines — Mountain pine beetle occurs throughout the range of pine in the Pacific Northwest. Infestations have resulted in ex- tensive mortality over large areas. In 1995, mountain pine beetle in eastern Washington was reported to have killed 406,000 trees of four different species of pine on 201,000 acres. 12 Precipitation NE Washington — Total annual r ; Year 80 ■^ 60 O -O _l 1- E-Q ^ c O O > = E 40 20 Fir Engraver Volume ■ Trees 1 .1 ■ I.I 400 300 200 100 3^ Year Precipitation in northeastern Washington was lower than normal most years between 1 985 and 1 994 (left). Fir engraver activity was also highest during this period (right), source: Washington Depannnent of Natural Resources (precipitation data); Cooperative Aerial Survey.Washington Department of Natural Resources and USDA Forest Service (insea data). Washington — 56 Table 3-1- -Effects of mountain pine beetle on eastern Wash ngton pines Effects Lodgepole pine Ponderosa pine Western white pine Whitebark pine Greatest impact High-density mature trees Immature pole-sized Big, old (>250 yr) trees Big, old trees I How it kills Many trees over extensive area Groups of several 100 Individuals Individuals Trees killed in 1995 (no.) 342,000 ■ Hi 52,000 11,000 1.000 ^^^^H Acres affected in 1995 (no.) 1 22,000 58,000 14,000 7,000 Tonasket « Loomis State Forest Washington Long-term management for the Loomis State Forest. The Ix>omis State Forest, west of Tonasket. is the largest block of state-owned forest land tn Washington. In addition to its designation as a common school trust land, managed to produce income for construction of public schools, the Loomis State Forest provides valuable habitat far the threatened North American lynx, roadless recreation sites adja- cent to the Pasayten Wilderness Area, water resources for downstream communities, and grazing land. Controversy has surrounded potential manage- ment of the forest, especially when such uses conflict . Conconully In the late 1 980s, a mountain pine beetle outbreak began to visibly affect portions of the Loomis State Forest containing old, large-diameter lodgepole pine. By 1 993, more than 20.000 acres had been affected, with an average of 40% of the timber volume killed on those sites. About 28,000 acres containing large-diameter lodgepole pine continue to be at risk of attack. The Loomis State Forest is the largest contiguous block (144,000 acres) of land managed by the Washington State Department of Natural Resources. To address numerous and conflicting concerns about managing this block, an 80-year plan has been prepared and approved. The Department of Natural Resources plans to accelerate harvest in the beetle- susceptible lodgepole pine stands and create a better mosaic of age structure. This strategy will improve lynx habitat and increase stand resistance to future attack by the beetles, while not precluding other forest uses. Washington — 57 Western pine beetle kills big, old, ponderosa pine — Western pine beetle some- times attacks ponderosa pine in the Pacific Northwest. Nor- mally, this beetle breeds in large, old trees; in windfalls; in trees infected by root disease; or in trees weakened by drought, overstocking, or fires. Losses are significant because large, old pines are under-rep- resented across the forested landscape in many areas in eastern Washington. Western pine beetle also attacks and kills trees of all ages that have bark sufficiently thick to pro- tect the insect during develop- ment. Aspen Satin moth and moisture stress are killing many aspen stands — ^Defoliation by satin moth has killed many aspen stands in north-central and northeastern Washington, the late 1920s Affected stands tend to be older than unaf- logical control Large, old, ponderosa pine, im- portant for their ecological and scenic value, are being killed by bark beetles in overstocked stands, especially in dry years. fected ones and apparently unable to withstand insect de- foliation. Moisture stress was likely a factor in the mortality. The defoliated stands were iso- lated from other hardwood stands and do not have many predators or parasites to keep the satin moth populations in check. Satin moth, introduced from Europe, was first found in North America in 1920, both in New England and in southwestern British Colum- bia. In the West, it has spread southward to northern Cali- fornia, and into the interior of Oregon, Washington, and southern British Columbia. After its introduction into Brit- ish Columbia, the satin moth was considered a pest of eco- nomic importance. With the introduction of European parasites of the moth during and early 1930s, successful bio- has generally been achieved. Satin modi larvae feed on aspen leaves (above). Entire groves of aspen can be defoliated by tlie satin mo^ (right). Older, moisture-stressed trees are the most vulnerable. 'f 'o.r ^;J .fc Washington — 58 CHAPTER 4. DISTURBANCE AND URBAN FOREST HEALTH Introduction An urban or community forest is the sum of planted landscape trees and remnants of the native forest intentionally or inadvertently left behind during the building of the city. Urban forestry is the discipline concerned with man- aging these forests. Urban forest health is less than ideal — The health of Oregon's and Washington's com- munity forests is poor in many towns and cit- ies. Erratic maintenance, old age, lack of species diversity, insects and diseases, devel- opment pressures, and weather combine to create a myriad of problems for urban trees. Although Oregon and Washington have been at the forefront in traditional forest manage- ment, their urban forestry practices have lagged significantly behind other regions of the United States. Most community forests have aging or overmature trees. Many of these trees were planted and left without adequate care, and others simply were the wrong trees in the wrong places. In Oregon and Washington cit- ies, tree replacement consistently lags behind tree removal, but recent surveys of Northwest communities show that tree planting is in- creasing. East of the Cascades, environmental changes, tree age, and pests are taking a great toll on community trees. Historically, the re- gion was planted with a few hardwood species, such as black locust, Siberian elm, poplars, and various conifers. Although tenacious, these species have characteristics some people consider undesirable, such as weak wood, messy fruit, and prolific sprouting, which can result in high maintenance costs. Replacing them with a diverse selection of more appro- priate species or cultivars will reduce mainte- nance costs and improve the health of the ur- ban forest. Tree topping stresses urban trees. Many land- scape trees have suffered from "topping, " the practice of indiscriminantly removing the large branches in the crown of a tree. Because trees need leaves to pro- duce energy, removing the canopy causes trees to slowly starve. With this stress, trees become more susceptible to insect and disease damage. Wounds created by topping provide places of entry for decay organisms. The resulting decay often goes unseen and undetected until the tree fails. Dead wood and poor branch structure also contribute total and costly tree failures. Li^Lj--L ii^ Urban — 60 Community forests have not escaped the insect and disease outbreaks plaguing the ru- ral forests. Many conifers like Douglas-fir and ponderosa pine are found in both rural and urban areas, and so too are the insects and diseases that afflict them. Management of the recent pandora moth outbreak in central Or- egon, for example, not only concerns the Deschutes National Forest, but also the city of Bend — though on a different scale. Descrip- tions of the more important insects and dis- eases of urban forests follow. Disturbance Agents In Urban Settings Fire and windthrow are a potential threat to homes in forested areas — Homes, increasingly being built at the urban-forest interface, are at risk of being destroyed or dam- aged by wildfires or falling trees. Trees with internal decay or root disease (such as lami- nated root rot) are particularly susceptible to Avindthrow or breakage during wind or ice storms. Thinning or removal of groups of trees to accommodate house construction may also lead to windthrow during storms; the remain- ing trees are often unstable because of height- to-diameter ratio and altered wind patterns. Home owners need to know that managing the vegetation around their homes is essential to protect their lives and prevent property dam- age. Where vegetation is not properly man- aged, the costs of fire protection and storm clean-up increases for neighbors, the commu- nity, and public agencies. Root rot disease often creates hazards when houses are built in forests (top). Removal of hazardous trees can be costly and unsightly (bottom). Removing or thinning trees during home construction can cause remaining trees to be unstable and prone to windthrow. Urban— 61 Dutch elm disease in western Oregon, 1 986 to 1 995. The 1 986 figures are from Eugene and Portland. The 1987 to 1995 figures are removals from Portland, plus a few trees from private home owners outside of Portland. Source: Oregon Department of Agriculture. Dutch elm disease is increasing in Oregon and Washington — American elm is an important component of the mature urban for- est environment, both east and west of the Cascades in the Pacific Northwest. Dutch elm disease is an introduced disease that has dev- astated trees throughout the United States and is of worldwide importance. This aggressive disease is spread from tree to tree by elm bark beetles, which cany disease spores, and also when the fungus grows from roots of an in- fected tree to roots of adjacent healthy trees. Dutch elm disease was first detected in Or- egon in the Nyssa-Ontario area and in Wash- ington in Walla Walla in the 1970s. Despite control efforts, the disease has since spread to other locations throughout the two states. The key to reducing spread and losses from this disease is prompt removal and disposal of infected trees, but many cities and towns have no such programs. In Oregon, many towns remove infected trees and dispose of the chipped wood at a solid waste site. The city of Portland injects elm trees with fungicides as a protectant against the disease. Gypsy moth — the vigil continues — The first European gypsy moths were discovered in 1974 in Washington in the city of Renton (near Seattle) and in 1979 in Oregon in Lake Oswego (near Portland). Since then, gypsy moth has been monitored annually by the Or- egon and Washington Departments of Agricul- ture. In 1995, more than 50,000 traps were deployed in Oregon and Washington, mostly west of the Cascades, where most population centers and gypsy moth host material are lo- cated. The 1995 gypsy moth monitoring in Oregon and Washington had the following results: Oregon Washington Traps placed (no.) 14,585 36,166 Total catch areas 10 40 Total moths (no.) 24 149 European 24 146 Asian 0 3 Hybrid 0 0 The newest arrival is the Asian gypsy moth; it is potentially more serious than the Euro- pean gypsy moth because females can fly, and they have an appetite for conifers. In the last The European gypsy moth larva, pictured here, feeds mainly on hardwood foliage. Its cousin, iJie Asian gypsy moth, feeds on conifers and so presents a greater threat to the Pacific Northwest Urban— 62 Gypsy moth was trapped in 13 counties in Oregon andWashington in 1995. Table 4-1 — Gypsy moth eradication sites in 1996 The Oregon Department of Agriculture keeps a steady watch on the gypsy moth l}irough an extensive trapping program. State County City Acres Treatnnent Oregon Multnomah Gresham 10 Ground application of Bt' Washington Clark Vancouver-Union no Ground application of Bt King Seattle-Beacon Hill 660 Ground application of Bt Seattle-Beacon Hill 360 Aerial application of Bt Seattle-Madrone Park 590 Aerial application of Bt Pierce Tacoma-Hillsdale 13 Ground application of Bt Tacoma-Proctor 19 Ground application of Bt Bonney Lake-Highlands 14 Ground application of Bt Thurston Black Lake 400 Aerial application of Bt Hunter Point 19 Ground application of Bt ' Bt is a microbial insecticide, composed of the bacterium, Bacillus thuringiensis. few years, several Asian gypsy moths have been trapped in Washington and British Columbia and one in Oregon, near ports where they have arrived on ships. The largest outbreak in the United States was in 1984, followed by the largest control ef- fort in 1985: 227,000 acres near Eugene, Or- egon, were treated with aerial applications of Bacillus thuringiensis (Bt), a microbial insecti- cide. In 1996, 10 sites in Oregon and Wash- ington were treated with Bt to eradicate the moth. Treatment areas are selected on the basis of gypsy moth species (Asian or Euro- pean), size of the population, and number of Urban— 63 egg masses. Past eradication treatments have been successful and, fortunately, neither the European nor the Asian gypsy moth has be- come established in the Pacific Northwest. The gypsy moth, however, is constantly being re- introduced, so annual monitoring is necessary. Dogwood anthracnose disease causes leaf blight, branch dieback, and tree death of ornamental and native dogwoods. Dogwood anthracnose has become estab- lished in the Pacific Northwest — ^Dogwood anthracnose, a very destructive disease of flow- ering dogwood, first appeared in the eastern United States in the early 1970s. It was first reported on native Pacific dogwood in Wash- ington in 1976 and in Oregon in 1983. As of 1994, the disease was present on Pacific dog- wood in most western Oregon and Washing- ton counties. Evidence suggests that this dis- ease was introduced from abroad, but its origin remains unknown. The disease causes leaf blight, branch die- back, and tree death on Pacific dogwood and several ornamental cultivars, and it is of par- ticular concern in ornamental landscapes. The greatest hope for long-term disease manage- ment is to develop disease-resistant dogwoods. Environmental stresses affect urban trees — ^Environmental stresses, such as too much or too little water, affect the health of trees in communities. Urban forests generally lack the complex forest floor that helps trees retain moisture and nutrients. Drought over prolonged periods can reduce the vigor of ma- ture trees and increase their susceptibility to insects and disease. Supplemental irrigation, even for established trees, is beneficial during dry, hot weather, but too much water can also be detrimental. Excessive summer irrigation, for example, leads to root rot and structural instability in Oregon white oaks. Building and maintaining cities affects tree health. Many existing tree health problems can be traced to soil compaction and root damage during construction, utility trenching, or power line clearance. Decay organisms enter me- chanical wounds and can create hazard trees. Pollution caused by automobile and industrial emissions also affects the health and longev- ity of community forests. Proper care and species selection will im- prove the health of urban trees— The care- ful observation and inventory of urban trees will detect many disease and insect problems. Given adequate funding, many can be treated. A diversity of tree species lessens the risk of catastrophic losses from weather extremes or introduced pests. Choosing the right tree for the right place, and regular pruning to remove dead wood and excessive twig growth will help keep trees healthy. As urban forests mature, the loss of older trees is inevitable. If commu- nities maintain mature trees and plant new trees, their forests will be healthier and future generations will enjoy a thriving urban forest. Urban— 64 »-"• J^Uk: ^^^rfj -r^ -i »,^ ot^T-Ajt-a •7* w^ > »-? •# Commitment is needed for long-term urban forest health. Commitment of citizens and local governments to long-term health of their community trees will result in thriving wbanforests. Interest in maintaining and improving the trees in their neigh- borhoods and towns is incredibly strong among residents and community organizations. Urban trees make towns and cities more livable, clean the air, screen noise, please the eye, and provide habitat for birds and other small animals; through these amenities, they make a city more attractive to potential businesses, tourists, and other sources of income. Policy makers should recognize that community trees are a worthwhile investment of time and money. Urban— 65 CHAPTER 5. FOREST HEALTH MONITORING PILOT PROJECT IN OREGON AND WASHINGTON Concerns and Information Needs frA 4ki>> [ FHM Plots"] u#*yto 4i^ Public Universities Land Managers Industry ^ [FHM and Other Data) [pHMReportT Implementing the national Forest Health Monitoring Program. Step I: measure indicators of forest condition from permanent field plots, aerial surveys, and other ground surveys; Step 2: analyze and interpret the results for various user groups; Step 3: determine how existing and future information can be used to answer specific (assessment) questions about forest ecosystems at national and regional scales. The Forest Health Monitoring Program is a multiagency national effort to monitor, assess, and report on the long-term status, changes, and trends in forest ecosystem health in the United States. (See appendix 4 for definitions of the kinds of forest health monitoring activi- ties.) Data from permanent field plots and other sources are used to prepare annual sum- maries and periodic regional and national re- ports on forest health for the general public, universities, resource managers, and Con- gress. Some important national and regional assessment questions that can be answered from uniformly collected field data are: • What proportion of the Nation's forests has reduced growth from past records? • Where are the risks of reduced growth in- creasing or decreasing? • Is the scenic quality of forests decreasing because of more observed damage? Monitoring — 66 --I Forest Health Monitoring IT** \ y Table 5-1 — Forest Health Monitoring indicators to assess forest ecosystem condition Forest Health Monitoring 1 994 field plots in California, Oregon, and Washington. In summer 1994, Forest Health Monitoring protocols were used to sample forest conditions of Douglas-fir habitats in Oregon and Wash- ington, from the Cascade Range crest westward to the Pacific Ocean. This work tested the ease of measuring various indicators of forest health in environmental conditions wetter than those in California. It also familiarized state forestry cooperators with field protocols they would be using in their forest health monitoring work and established baseline conditions for Dou- glas-fir forests related to the different indica- tors measured. Establishing and interpreting baseline conditions (see appendix 4) is critical to reviewing management options for old- growth stands and adaptive management ar- eas. Results from this work, hereafter called the Pilot Study, are explained in the rest of this chapter. Many forest health monitoring indi- cators (table 5-1) have been tested for 6 years in regional pilot studies across the United States. The following sections define those Indicators Indicators cont. Growth Crown condition Leaf area Plant species composition Lichen community structure Bioindicator plants Songbird habitat Nitrogen index Regeneration Mortality Tree damage Soils: Acidification index Organic carbon status Disturbance recovery index indicators measured in the Pilot Study, de- scribe results from field sampling, and inter- pret their significance for Northwest forests. When possible. Pilot Study results are com- pared to 4-year Forest Health Monitoring data from about 200 plots measured in California, 1992 to 1995. GENERAL SITE AND SPECIES CHARACTERISTICS Twenty-five plots, each about 2.47 acres, were sampled in the Pilot Study — 12 in Wash- ington and 13 in Oregon. Elevations ranged from <30 feet to about 7,600 feet. Stand ages ranged from <10 to 300 years. Oregon sites were older, at higher elevations, and on steeper slopes than Washington sites; aspects varied across both states. Conifers were the domi- nant vegetation. As expected, the predominant forest type on the 25 plots was Douglas-fir Forest Type Percentages Douglas-fir Fir-Spruce Hemlock-Spruce Other Softwoods Mixed Conifers Percent of Total Frequency Monitoring — 67 (70%), followed by hemlock-spruce (17%); some plots had small amounts (about 4% each) of fir-spruce, mixed conifer, or other softwoods. Stand Characteristics Each forest stand has unique understory and overstory traits distinguishing it from other stands with similar or different species. To- gether, these traits are called stand character- Azimuth I -2 360° Azimuth 1-3 120° Azimuth I -4 240° \ Hectare Plot 185.1' radius (5i.4m) National FHM plot layout is designed around four points (subplot centers) Forest Health Monitoring field plot layout. istics. Tree and seedling characteristics at Pilot Study sites were measured in four circu- lar microplots and subplots of known size, permitting results to be calculated per unit area. Economic, scenic, and biodiversity val- ues can then be attributed to larger landscape- sized areas, allowing resource managers to decide between different management options. Understory Vegetati o n Presence and abundance of understory cover indicate status of seedling regeneration, percentages of various vegetation ground cover, and which ground cover may be competing with new or established seedlings for soil mois- ture and nutrients. Understory measurements were taken in small microplots, at right angles Understory Vegetation Cover Ferns MHUm Herbs BH^^H Lichens 1 Seedlings 1 0 10 20 30 40 50 Mean Cover (%) to each subplot. Ground-cover percentages for Pilot Study sites are shown in the figure above. Pilot Study plots had about the same per- centage cover for herbs, lichens, and seedlings as did the 1992-95 California plots. Shrub cover was twice, fern cover was nine times, and moss cover was ten times higher in Pilot Study plots. Pilot Study seedlings seem to face greater competition from shrubs and ferns than do plot seedlings in California, probably because of wetter growing conditions. Overstory Vegetation Forest managers commonly summarize characteristics of small and large trees — sap- lings, poles, and sawtimber — growing above the forest floor and having similar height and di- ameter limits (table 5-2). Seedlings and sap- lings were recorded within microplots and pole and sawtimber-sized trees within subplots. Field tallies showed 79 sapling, 448 pole, and 275 sawtimber trees. Table 5-2 — Size classes of forest ecosystem components Class Range limit Understory seedling Seedlings Saplings Poles Sawtimber < I ft tall > I ft tall & < 1 .0 inch diameter > 1.0 to 4.99 inch diameter 5.0 to 10.99 inch diameter (hardwood and softwood) at least I 1.0 inch diameter Monitoring — 68 The average number of subplot saplings found in 1992-95 California plots, four indi- viduals, was almost the same as the average for the Pilot Study plots, three individuals. Pilot Study sites, however, had one-third more pole (18 vs. 12 individuals) and about twice as many sawtimber trees (11 vs. 6 individuals). More plot and unit-area pole and sawtimber trees in Oregon and Washington (table 5-3) probably reflect older stands that have more overs tory trees. Washington plots had char- acteristics of younger stands compared to Or- egon plots: twice the number of saplings and about 1.5 times as many poles. Table 5-3 — Plot structure data for the Northwest Pilot Study Data in managed and unmanaged stands (table 5- 4). Higher values in Oregon reflect those for older stands. In the California 1992-95 data, live basal area averaged about 96 square feet/ acre, including pole and sawtimber trees for all species. Table 5-4 — Basal areas typically found for different species and age classes in Northwest forests Species (age range in yr) Basal area ranges (ftVacre) Douglas-fir (0-750) Western hemlock (100-500+) Western redcedar ( 1 00-500+) Red alder (0-1 00) Bigleaf maple (100-400) 20-180+ 40-180 0-80+ 0-20 0-20 Oregon Washington Number of trees per acre Saplings Poles Sawtimber Totals 78 45 33 159 63 34 156 256 Basal Area Basal area is a measure of the total cross- sectional area of tree boles at breast height in square feet. The higher the value, the more cross-sectional area is oc- cupied by bole wood. How the bole wood is partitioned, however, deter- mines economic value as well as in- fluences habitat diversity. If large total basal area is spread over many very small stems, they are probably not merchantable for posts, poles, or pulp. Many small old stems produce densely shaded stands that do not usually allow growth of thick understory vegetation. The average Live basal area combined for poles and saw- timber was 204 square feet/acre in Oregon, and CROWN RATINGS Many factors affect seedling and tree growth: internal factors are vigor and age of the plant and external ones are light, water, and nutri- ents. Light reaching a tree or seedling is in- fluenced by the individual's position in the canopy; relative position to neighbors; and the shape, size, and condition of the crown. Thus, crown evaluations indicate whole tree condi- Vigor Class I >l/3 total height in foliage; <5% dieback in crown; >80% of foliage is normal Vigor Class 2 does not meet Class I or Class 3; any crown length; may or may not have dieback; 21 to 79% foliage is normal Crown dieback Missing fotiage Vigor Class 3 any crown length; I to 20% normal foliage or sum of dieback + abnormal foliage >80% 154 square feet/acre in Washington. These val- ues are well within ranges typically found Total height 4.5 ft ( 1 .4 meters) Crown length 1 .9 ft (0.6 meters) Live crown ratio 42% 4.5 ft (1.4 meters) 1 .4 ft (0.4 meters) 31% 4.3 ft ( 1 .3 meters) 0.6 ft (0.2 meters) 14% Sapling crown vigor classes. Monitoring — 69 Sapling Crown Vigor for All Species Good Average Poor Crown Vigor Class (saplings 1.0-4.9 in. DBH) Hardwood/Softwood Sapling Vigor Good Poor Average Sapling Vigor (saplings 1 .0-4.9 in. DBH and larger) tion by indirectly assessing its ability to capture light and produce carbohydrates by photosynthesis. Crown condi- tion indicators used in this re- port are sapling crown vigor, crown density, crown dieback, and foliage transparency. Crown density A 2-dimensional viev» of foliage, branches, and reproductive structures {%) tfiat obstruct ligtit penetra- tion througfi tfie crown. Example below has a density of about 50% Crown dieback Foliage transparency The percentage of branch A measure of sunlight (%) tips dying back from the filtering through needles crown edge. Normal death j and leaves in the crown, by shading is not counted. Sapling Crown Vigor Sapling crown vigor was evaluated for 79 saplings. High ratings in the good and average categories (vigor class 1 and vigor class 2) indicate more foli- age area available for photosynthesis. Across all species, the sum of good and average sapling vigor was 94%; only five saplings (6%) had poor vigor (vigor class 3). Almost twice as many hardwood sap- lings had good vigor compared to soft- wood saplings, but the sum of good and average vigor for both was >90%. Over 90% of all saplings in the Pilot Study and California 1992-95 plots had high (good + average) crowm vigor ratings. Crown Density Crown density represents the relative amount of foliage, branches, and repro- ductive structures that obstruct skylight visibility through the crown. Young emd old trees with vigorous growth generally have full crowns and high density val- ues— a condition indicating more foliage area available for photosynthesis. In- cluding all species and trees, 96% of Pi- lot Study trees had high (good + average) crowm density ratings. Hardwoods had a lower percentage of good ratings but a larger percentage of average ratings. These findings were similar for all trees and species by state. The lower percent- age of good ratings in Oregon probably reflects lower vigor of older stands sampled there. Crown density, crown dieback, and foliage transparency raljng example. Monitoring — 70 Crown Density for All Species d Average Crown Density Class Hardwood/Softwood Crown Density Poor Good Average Crown Density Class (trees 5.0 in. DBH and larger) Crown Densities in Oregon and Washington 60 O S 50 §•40 Q- o 30 g 20 ■ Hardwoods ■ Softwoods 41 i |_^ Good Average Poor Crown Density Class (trees 5.0 in. DBH and larger) Crown Dieback for All Species Crown Dieback Crown dieback is the total percentage of branch tips dying back from the crown perimeter, except dieback caused by shading and competition from neighboring trees. Die- back is caused by severe shock to root systems from drought or disease. Some species also will show light dieback as part of their normal growth, but too much die- back reduces foliage area available for photosynthe- sis. No crown dieback was detected on 95% of Northwest Pi- lot Study trees. The no-damage class was split about equally between hardwoods and soft- woods. By state, percentages of trees with none, light, mod- erate, and severe ratings were almost identical to those rat- ings when all Pilot Study trees were combined. In the Pilot Study, western hemlock comprised 1% of the total population's severe die- back and the "Other Hard- woods" class had 6% severe dieback. In the 1992-95 Cali- fornia data, oaks comprised Normal Light Moderate Severe Crown Dieback Class (trees 5.0 in. DBH and larger) about 1% and fir-spruce about 1.5% of plot trees with severe dieback. Severe dieback was noted for all major species groups in the 4 years of California data, but some species were affected more in certain years. For example, Douglas-fir, oak, redwood-sequoia, and true fir all had severe dieback in 1 992 — the end of a 7-year drought. Only oaks in 1993 and 1994 and only oaks and pine in 1995 had severe die- back. Foliage Transparency Foliage transparency measures light filter- ing through needles and leaves in the crown. Transparency values differ by species and de- pend on natural branching habit and foliage orientation. High transparency values indicate unhealthy crown conditions because less foli- age area is available for photosynthesis. Re- duced foliage area can be caused by insects, disease, and other stressors. In Pilot Study plots, 98% of all trees had normal (0-30%) transparency ratings. A slightly higher per- Foliage Transparency for All Species Normal Moderate Severe Foliage Transparency Class (trees 5.0 in. DBH and larger) Hardwood/Softwood Foliage Transparency t Hardwoods I Softwoods Normal Moderate Severe Foliage Transparency Class (trees 5.0 in. DBH and larger) Monitoring- centage of softwoods than hardwoods had nor- mal transparency ratings; this trend was re- versed for moderate (31-50%) and severe (>50%) transparency classes. By state, about 98% of all trees had normal transparency rat- ings. Trees in both Pilot Study and the 1992- 95 California plots had almost identical high percentages (>95%) of trees with good and moderate transparency ratings. DAMAGE Pathogens, insects, air pollution, and other natural or human disturbances can affect tree growth and development. Damage caused by any agent, alone or in combination, can influ- ence forest condition. Recording observable damage signs and symptoms provides valuable information to assess forest condition and to interpret any deviations from baseline condi- tions. Field crews recorded damage symptoms seen in field plots when the observed damage could kill the tree or affect its long-term sur- vival. Damage codes have two parts: the general location of injury and the damage type (table 5-5). Data are recorded for all live microplot saplings and all subplot live trees. Trees are observed from all sides, starting at the roots. Priorities are set for damage signs and symp- toms and recorded by general location in the following order: roots, roots and lower bole, lower bole, lower and upper bole, upper bole, crown stem, branches, buds and shoots, and foliage. The numeric order (table 5-5) denotes decreasing significance as the code number goes up — for example, damage code 02 Upper bole (05) Midpoint of bole (Midpoint between crown base and "stump") Lower bole Roots/"stump"/ (03) lower bole (02) Foliage > (09) Buds/shoots (08) Branches (07) Crownstem (06) Base of live crown Lower and upper bole (04) (01) Damage locations and codes. Monitoring — 72 Table 5-5 — Damage types recorded in the 1 996 Pilot Study Damage code Description Severity threshold percentage (in 10% classes to 99%) 01 Canker 20 02 Conks, fruiting bodies, and other indicators None 03 Open wounds 20 04 Resinosis or gummosis 20 II Broken bole or roots <3 ft from bole None 12 Brooms on roots or bole None 13 Broken or dead roots, >3 ft from bole 20 21 Loss of apical dominance; dead terminal 1 22 Broken or dead branches 20 23 Excessive branching or brooms 20 24 Damaged foliage or shoots 30 25 Discoloration of foliage 30 31 Other None (conks — internal fungal decay) is more signifi- cant than code 03 (open wounds). This rank- ing is developed by insect and disease special- ists who have found that the most serious kinds of damage are those nearest the ground where a tree's main stem is anchored in the soil. When more than a single type of damage is in the same place, the most damaging symp- tom (lowest damage code) is recorded. Dam- age is recorded for up to three locations on one tree. Specific causal agents are not identified in detection-monitoring field assessments but a determining cause is critical in evaluation monitoring (appendix D). About 80% of the Pilot Study trees and 75% of Cali- fornia trees had no damage symptoms. The no-damage percentage for California re- serve (national parks, wilder- ness) and drier woodland ar- eas, however, was about 60%. The most common damage symptoms were conks, dead terminal branches, and open wounds, which together repre- sented about 10% of all trees. Conk damage, indicating inte- rior fungal decay in the tree bole and stem, was the great- est single damaging agent both in the Pilot Study and the 1992-95 Cali- fornia plots. The no-damage percentage of about 80% for all trees across all three states was not anticipated because tree species, cli- mate, environments, disease, and insect fac- tors differ so widely from north to south along the Pacific Coast. The lower 60% no-damage value for reserve and woodland land classes in California means that older stands or more stressed environments have a lower no-dam- age baseline. A major deviation from these no- damage baseline values of 60 and 80% will indicate presence of one or more significant stressors. Damage Types in Oregon and Washington None Conk P ^™ ■ Dead terminal 1 Open wound 1 Damage shoot 1 Resinosis Discolor i Broken branch i Canker 1 1 Broken bole Broken root Excess branch Other 3 20 40 60 80 l( )0 Percent of Population FULL-HECTARE TALLY The full-hectare (2.47 acre) tally is done only in the Pacific Northwest and in California, at the request of federal and state cooperators who provide additional funding for its imple- mentation. Need for the extra tally arose in summer 1991 when a California pilot plot in a sequoia forest had no recently dead or live large trees in any of the four subplots. Because the overstory of many Northwest forest types has similarly large trees, the concern of California, Oregon, and Washington state cooperators was that subplots would not capture a represen- tative number of large live and dead trees. Thus, protocols were changed so that field crews searched the entire 2.47-acre plot area for both large recent dead trees (>11.0 inches) Monitoring — 73 Subplot vs 1 .0-hectare Tallies ■ Subplot Recent tally ■ Hectare nortallty ^^^^^^^^^^H ; plot tally Large 1 Trees 20 40 60 8( Number of Individuals 100 that had died in the last 5 years and large live trees (>40 inches). Pilot Study subplots had almost no recent mortality (1 vs. 55) and few large live trees (5 vs. 93) compared to numbers tallied on full- hectare plots. More large live trees were found on 25 plots in Oregon and Washington in 1994 than were recorded for almost 200 California plots measured in 1992-95. Pilot Study field work was restricted to Douglas-fir habitats in western Oregon and Washington. These for- ests have a high percentage of large-diameter trees not tallied in subplot-only data. The sig- nificance of this work is that larger plots will be needed to characterize true overstory con- ditions in Oregon and Washington forests when operational field work starts in the future. Published results for 1992-95 California for- est health monitoring data show that per area estimates of recently dead trees based on sub- plot-only data were significantly different than estimates made from the full-hectare tallies. VEGETATION STRUCTURE Vegetation structure indicators provide in- formation on species composition, relative cover amount, and spatial distribution of vas- cular plants in the forest. Vegetation measure- ments help describe plant biodiversity and quantify habitat structure, which in turn in- fluences wildlife biodiversity and distribution in forest ecosystems. Vegetation structure indicators provide a natural link to other in- dicators including songbird habitat, crown condition, regeneration, and species diversity. Vegetation observations and collections are taken in 10.8-square-foot permanent quadrats; each subplot has three quadrats. Three kinds of information are taken for each quadrat: spe- cies identification, height class in which each species occurs, and plant canopy cover. Data were collected for four strata: stratum 1 is from the ground to 2 feet; stratum 2 is from 2 to 6 feet; stratum 3 is from 6 to 16 feet; and stra- tum 4 is from 16 feet to the forest canopy. Botanists worked from the lowest stratum upward and used a calibrated range pole and the quadrat frame to define the sample area. Specimens of unknown plants were collected outside the subplots, dried, pressed, labeled, and submitted to the Oregon State University Herbarium, Corvallis, for identification. Some 193 species were identified in 25 Pilot Study plots. Eleven species were found at 9 or more of the 25 sample sites (table 5-6). As expected, ground and understory layers (strata 1 and 2) had the most species and high- est number of observations per species. Stra- tum 4 had the greatest total cover and the fewest species. Botanists collect vegetation structure information in subplot quadrats. Monitoring — 74 Vegetation Structure within 4 Strata E 3 First ~ JB ■ 1 1 1 Second f Third 1^^^^ Fourth ^^^^^^^ ■ No. of Species ■1 No. of Observations ■ Total Cover ■ 1 50 100 ISO 200 250 300 Mean Value LICHEN COMMUNITIES' Lichen communities provide information about several key monitoring questions such as contamination of natural resources, biodiversity, and sustainability of resource production. Hundreds of papers published worldwide in the last century document the close relation of lichen communities to air pol- Table 5-6 — Most common plant species Common name Sites (no.) Acrobolbus Red alder Twin flower Oregongrape Red blueberry Western salal Starflower Pacific blacl50% of 25 field plots^. General conclusions from the lichen collection work were: • The lichen community sampling method was used effectively in the Pacific Northwest with- out altering methods used in other regions of the United States. • Species richness values found in the Pilot Study were somewhat lower than those found in the Southeast, higher than in Colorado, and similar to California. • Methods appear to be fairly repeatable across sites, but some differences between observ- ers emphasized that good training and qual- ity-assurance checks are needed to achieve a good representation of all species present. • Results can be used to evaluate biological effects of deteriorating air quality after a re- gional air-quality model is implemented, as has been done in other regions. SONGBIRD HABITAT INDICATOR' Populations of many songbird species are strongly influenced by local forest structure, which affects microclimate, availability of for- aging and nesting sites, and risk of predation. In addition, because some forest birds are sen- sitive to the size and shape of forest stands, their presence or absence can reflect habitat quality at broader scales. Songbird commu- nities can thus act as indicators of the effects of forest disturbance. During the summer of 1994, songbird sur- veys were conducted in conjunction with veg- etation measurements on 60 study sites in the Cascade Range of western Oregon and Wash- TTie eight most common species and their percentage occurrence across 25 plots were Hypogymnia enteromorpha. 60%; H. inactiva, 52%; H. physodes. 72%; Parmelia sulcata, 72%: Platismatia glauca. 80%; P. heirei. 52%; Ramalinafarinacea. 52%; and Usnea spp., 68%. ^Adapted from; Cooperative Agreement Report: Wildlife habitat indicator-Pacific Northwest Pilot Study Report. Grant E. Canterbury and Thomas E. Martin, Montana Cooperative Wildlife Research, University of Montana, Missoula, MT. 1995. 11 p. ington. Forests on these study sites were domi- nated by Douglas-fir and western hemlock. The goals of this study were to collect data on bird communities along a forest disturbance gradient, develop habitat models to predict bird community composition from vegetation pa- rameters measured by Forest Health Monitor- ing crews, and test bird survey methods that had previously been used successfully in southeastern pine forests. Four 50-meter-radius bird survey plots were established at each site. Plot centers were 492 feet apart, covering an area of about 15 acres, so the probability of detecting the same indi- vidual birds on more than one plot was low. Measurements included number and species of birds seen within each plot, estimated canopy cover, shrub density, understory veg- etation, and sapling and tree data. Sites ranged from recent clearcuts to old-growth for- ests. A recorder conducted 20-minute bird surveys at each plot between 6:00 and 10:00 AM, except during rainy or windy weather which could interfere with detection of birds. Because songbirds are easily surveyed and show a variety of responses to forest habitat structure, the species on a site can be used to indicate the effects of forest disturbance on bird communities. In the Pacific Northwest, two groups of 16 disturbance-sensitive species and 16 disturbance-tolerant species were iden- tified from the ornithological literature (table 5-7). Each group responds primarily to major forest disturbances such as clearcutting or agricultural clearing rather than relatively mi- nor disturbances such as ground fires and selective cutting. Bird species intermediate in habitat preference between disturbed and mature forests were not assigned to either group. A Bird Community Index indicating the de- gree to which forest bird communities are al- tered by disturbance was developed from a modified ratio of species abundance in the two disturbance groups. The Bird Community In- dex was strongly influenced by vegetation char- acteristics on the study plots. About two-thirds of the variability in Bird Community Index val- Monitoring — 76 Table 5-7 — Songbird and habitat relations in Dou- glas-fir ecosystems Disturbance tolerant Disturbance sensitive Dark-eyed junco MacGillivray's warbler Rufous hummingbird American robin Spotted towhee Orange-crowned warbler House wren Black-headed grosbeak Northern flicker Song sparrow White-crowned sparrow Willow flycatcher Olive-sided flycatcher Fox sparrow Lazuli bunting Warbling vireo Hermit warbler Townsend's warbler Winter wren Chestnut-backed chickadee Pacific-slope flycatcher Golden-crowned kinglet Red-breasted nuthatch Steller's jay Hammond's flycatcher Varied thrush Hairy woodpecker Gray jay Pileated woodpecker Red-breasted sapsucker Red crossbill Brown creeper ues was explained by a model including two vegetation variables: deciduous and coniferous canopy cover. This study indicates that the field methods used to survey songbirds and their habitat in the southeastern United States also work in the Pacific Northwest. A preliminary model now exists to use Forest Health Monitoring vegetation data to predict Bird Community Index values for a stand. Thus, local habitat structure can indicate whether bird commu- nities should be dominated by species typical of mature forests or those typical of disturbed, early-successional habitat. These predictions can be checked in the field against actual bird communities to validate the model and deter- mine whether other factors such as climate or regional fragmentation of forests are also af- fecting bird populations. CONCLUSIONS Limited baseline data from forest health detection monitoring now exist for Douglas-fir habitats in 13 Oregon and 12 Washington Pi- lot Study plots sampled west of the Cascade Range in the summer of 1994. Cooperators in both states learned regular and quality-con- trol protocols needed to remeasure these plots and start statewide future operational mea- surements. All indicator measurements were successfully completed with field methods tested in 18 states, including California, since 1990. The total Pilot Study data set is small, and interpretations must be used with caution. Seedling and lichen ground-cover percent- ages ( 1 to 4%) were similar in Pilot Study and about 200 California plots sampled in 1992- 95. Wetter environments and older stands in the Northwest probably produced higher ground percentages of ferns (18%), mosses (35%), and shrubs (41%) plus more pole- and sawtimber-sized trees. Most Pilot Study sap- lings had either good or average vigor, indicat- ing good general health; some differences were found between hardwood and softwoods. More than 95% of all Pilot Study trees had good crown ratings as shown by normal foliage transparency, good to average crown density, and little severe dieback. Differences in Pilot Study and California crown ratings were mini- mal. Similarly, about 80% of sampled individu- als across all three states had no damage symptoms. Conks, broken tops and branches, and decay indicators were the most common damage classes. Forest canopies throughout the Northwest have many large dead and live trees. Such trees were successfully tallied in large full-hect- are (2.47-acre) plots but not in small subplots. Remeasurement and future work in Pacific Coast states will require using larger plots. Vegetation structure data were collected for four strata in all plots. The greatest number of individuals and species were tallied in those strata (1 and 2) nearest the ground. Lichens were found in all plots; the average number of macrolichens per plot was 15. A songbird habitat study produced a model that can use vegetation structure data from Forest Health Monitoring plots to predict whether expected birds will be typical of mature or disturbed for- est types. Monitoring — 77 CHAPTER 6. THE FUTURE OF OREGON AND WASHINGTON FOREST HEALTH People, as part of the natural environment, have always used forests for their needs. These needs have changed over the years, from gen- eration to generation, and will change in the future. And, at any one time, different uses will be championed by different people. What is perceived to be healthy, or not, may differ between users. But no matter what the forests are used for, they can be considered healthy when disturbance agents, such as fire, insects, and pathogens, remain within limits set by the variability of natural ecosystems. Put another way, forest health is the condition where dis- turbances not only do not threaten manage- ment objectives but work to maintain desired, sustainable ecosystems. Management, monitoring, research, and public education are the keys to restoring, maintaining, and improving forest health. • Management, or manipulation of the forest by various practices, is a valuable tool to help reach a desired outcome within a specified period. A variety of mcmagement options to improve forest health in Oregon and Wash- ington are described below. • Monitoring is necessary to establish initial forest conditions (the "baseline") and to de- tect changes in those conditions. During implemention of new or untested strategies, monitoring helps determine whether those strategies produce the desired effect. • Research is an ongoing need in forest man- agement. Shifts in the focus from stand man- agement to watershed and river basin man- agement require new understanding of the relations between forest organisms and how management practices might affect these or- ganisms individually and collectively over en- tire landscapes. • Public education and educational programs are needed to promote understanding of the complexities of forest health and their rela- tions to forest resources, uses, and manage- ment activities. Thinning reduces competJtion, stress, and bark beetle susceptibility. The Future — 78 EAST OF THE CASCADES Healthy or not? — ^Forest conditions in east- ern Oregon and Washington have been steadily changing for more than 100 years. Many dis- turbances in forest stands have altered fre- quencies or intensities compared to historical ones, often outside the natural range of varia- tion. Much of the change in disturbance re- gimes is due to Are suppression and selective harvesting in the last century. Both practices have resulted in significant changes in the dis- tribution and structure of forest vegetation: more true fir and Douglas-fir on low-elevation sites where pines and larch formerly predomi- nated, many overstocked mixed conifer and pine stands, and more multistoried stands. Key differences between historical and present disturbance patterns are described below: • Outbreaks of defoliating insects, such as western spruce budworm and Douglas-fir tussock moth, are now larger, more intense, and more frequent. • Bark beetle mortality, associated with tree stress and overstocked stands, is more preva- lent. • Drought periods in the late 1980s and early 1990s, coupled with overstocking, contrib- uted to increased susceptibility to insects, diseases, and Are. • Many root diseases and dwarf mistletoes are more widespread and destructive because of changes in forest structure and past harvest practices. • Fire is less frequent now but much more dev- astating on lower elevation, dry sites. The fire hazard on these sites is higher because of fuel buildup. Prescribed fire reduces fuels and thins the stand by k/7//ng some of the smaller and more fire- susceptible tree species. The Future— 79 Solutions — Although the current forest con- ditions are accepted as "normal" by many, we believe these east-side forests are unhealthy and in need of renewal and restoration. Re- source managers and land owners have sev- eral options for managing their forests to achieve long-term forest health. Prescriptions for harvest, stand improvement, riparian res- toration, or wildlife enhancement can be tai- lored to improve forest health and, at the same time, to achieve resource management objec- tives. There are a number of ways to return sites to historical, or other desirable, conditions to reduce their susceptibility to fire, insects, pathogens, and drought: • Thin stands to reduce competition, stress, and bark beetle susceptibility. • Harvest certain species such as lodgepole pine to create a mosaic of age classes across the landscape to prevent widespread out- breaks of bark beetles. • Design site-specific regeneration (natural or planted) to promote desired species compo- sition. • Keep in mind the effects that various activi- ties (such as thinning, harvest, or replanting certain species) will have on root diseases and dwarf mistletoes. • Reduce fuel loading to decrease destructive, stand-replacing fires. Once fuels are reduced to manageable amounts, prescribed fire can be used more safely and effectively. • Introduce prescribed fire that mimics natu- ral light ground fires to maintain a low fuel load; remove fire-susceptible species such as Douglas-fir and true fir; and use fire to re- generate species such as larch or quaking aspen that depend on fire or other distur- bance to create appropriate seedbeds or stimulate root sprouting. Several years after thinr)ing ar)d prescribed fire. The Future— 80 Reducing Bark Beetle Damage in eastern Oregon and Washington. When sufficient susceptible host material is available, bark beetle populations can become primary pests, capable of killing otherwise healthy host trees. Outbreaks subside when suitable host material is depleted. We recommend the following actions to minimize bark beetle damage: • Keep trees well-spaced and, therefore, vigorous; thinning changes stand structure, disrupts beetle movement, and increases vigor tn residual trees. • Thin or clearcut lodgepole pine stands approaching 60 to 80 years of age or 8 to 10 inches in diameter A long-term strategy for reducing damage from mountain pine beetle in lodgepole pine is to maintain a mosaic of age classes, preventing the whole landscape from being covered with uniform, highly susceptible stands at the same time. • Remove or destroy trees that currently contain bark beetles before the spring after the initial attack. Trees that have been killed by bark beetles generally do not perpetuate risk of additional insect or disease damage to the stand after the first year. Kri^-aTiE';?-- -; »V5?%. i'.Ui'^. ■ : i 'i-^f. /■• ^c'*/^.' *.">-■! r ■■ Quaking aspen needs fire to successfully regenerate from the roots of burned, killed trees. The Future— 8 1 Minimizing effects from, defoliators. Factors that favor survival of western spruce budworm, Douglas fir tussock moth, and hemlock looper include stands with a predomi- nance of host species, mature stands with large crowns and many nutritious reproductive buds, and a multilayered canopy with host species in both the overstory and understory. We recommend the following actions to unprove stand and host tree resistance to defoliators: • Maintain a diversity of serai forest stages with mixed host and nonhost species. • Where feasible, convert mixed stands of Douglas fir, true fir, and associated species threatened by defoliators to stands composed primarily ofponderosa pine, western white pine, and smaller proportions of western larch and Douglas-fir. • Maintain or manage for reasonable stocking density. • Maintain or manage for low vertical diversity. WEST OF THE CASCADES Healthy or not? — ^Natural forests in west- ern Oregon and Washington have been reduced and fragmented by urbanization and logging in the last half-century. Widespread harvest and replanting have reduced diversity of spe- cies and structure in many areas. But, unlike in east-side forests, changes in natural distur- bance regimes are neither as widespread nor as dramatic. The continued good health of west- side forests is, however, still threatened by the following changes: • Incidence emd damage by native forest patho- gens, particularly root diseases, have in- creased because of past forest management practices. • Introductions of exotic pests have risen dra- matically over the past century with increased commerce, travel, and new people moving to the Northwest. • Air pollution has worsened in the Willamette Valley and Puget Sound areas with increased population and industry. Ozone and other pollutants can damage forests near and far from pollutant sources. • Periods of drought have contributed to sus- ceptibility of trees to attacks by insects and pathogens. • Stresses on urban trees from air pollution, mechanical injury, and poor maintenance, have increased in many cities and towns. • Fire, wind, and disease are hazards to trees, people, and homes in the urban-forest inter- face. Solutions — Improving forest health in west- em Oregon and Washington can be approached from two directions: maximizing forest manage- ment options and minimizing urban impacts. In forested areas on the west side, resource managers and land owners have several options for managing their forests to achieve long-term forest health. Although restoration efforts over large areas are not usually called for, changes at a smaller scale can be beneficial. Some strat- egies for forest health improvement in western Oregon and Washington include the following: • Shift stands from single species to multiple species to reduce insect outbreaks and prolif- eration of diseases. Tradeoffs between maxi- mizing timber production (traditionally with even-aged, single-species plantations) and minimizing insect and disease damage must be examined. • Replant harvested or restored areas with seed- lings grown from local seed sources or use natural regeneration. Severity of diseases such as Swiss needle cast is much less when trees are adapted to the site. • Maintain a mosaic or mix of species and age classes, preventing the whole landscape from being dominated by uniform, highly suscep- tible stands. The Future— 82 Is root disease more common now than in the past? In general, root diseases were probably less frequent and in smaller centers in the past than currently. Why? • Harvesting root-diseased trees left infected roots in the ground and increased chances for contact with roots of healthy trees. • Regeneration of root-disease-susceptible species has been encouraged. • Compaction on sensitive soils has reduced vigor of residual trees, leaving them more vulnerable to armillaria root disease. • Fire suppression has favored root-disease-susceptible species. • Injury of roots and lower stems during harvest operations can attract insects that spread black stain root disease in susceptible hosts. • Creation of more stumps has resulted in more habitat for some root disease fungi Insect and disease damage can often be reduced by planting seedlings of resistant or tolerant species and using local seed sources. The Future— 83 The effects of people on west-side forests can be lessened several ways. As the population in the Northwest grows, the following remedial or preventive actions become ever more cru- cial to forest health: • Reduce air pollution through a variety of strategies and new technology so that produc- tion of ozone and other pollutants that dam- age forests can be reduced or, at the very least, not increased. • Maintain programs to monitor and eradi- cate exotic pests, and to prevent new introduc- tions. Where exotics already are established, prevention activities, such as the resistance breeding program for white pine blister rust, are crucial to the survival of native tree spe- cies. • Plant and care for trees and other vegeta- tion in urban areas. Use species adapted to the local climate and able to withstand stresses associated with an urban environment. • Manage for hazards such as fire, decay, and root disease in urban-forest interfaces. The white pine blister rust resistance breeding program in Cottage Grove, Oregon, inoculates l^iousands of white pine and sugar pine seedlings with blister rust to find a few resistant individuals that can be propagated. Urban tree selection and care are important to ensure longevity and safety of community trees. SOUTHWEST OREGON Conditions and changes in distur- bance patterns over the past century in southwest Oregon share similari- ties with both eastern and western Oregon and Washington. The effects of fire suppression and past harvest- ing influenced and changed current vegetation conditions, much as they did east of the Cascades. Memy sites are overstocked, prone to insect out- breaks, and have high fire hazard. A period of drought in the late 1980s and early 1990s, coupled with over- stocking, contributed to susceptibil- ity to insects, disease, and fire. Ex- otic diseases, such as white pine blister rust and Port-Orford-cedar root disease, have had significant ef- fects on five-needled pines and Port- Orford-cedar, respectively, and their management. Strategies for improv- ing forest health are similar to those for eastern and western Oregon and Washington. The Future— 84 Restoration of five-needle pines. Where western white pine, sugar pine, and whitebark pine are being killed by blister rust and bark beetles, several options are available to improve their vigor and resistance: • Density Tnanagement treatments, such as thinning or underburning, increase vigor and make trees less prone to bark beetle attack, particu- larly in stands with large sugar pines. • Underburning to maintain clear ground for seed hiding by birds is essential for whitebark pine regeneration. • Rust-resistant western white pine and sugar pine is available to be planted on sites where risk of blister rust infection is high. THE FUTURE Citizens, forest owners, and resource man- agers must all become active to solve forest health problems in Oregon and Washington. Without cooperation and in- teraction among groups with diverse and opposing view- points, future needs and de- sires for products and ser- vices from regional forests will not be met. East of the Cascades, the risks of uncontrollable, stand-replacing wildfires and widespread insect out- breaks are very great unless fuels and tree densities are reduced. West of the Cascades, the continued in- troduction of exotic insects, diseases, and plants threaten the existence of native for- ests and, without continual vigilance, chances of establishment and spread are much greater. Air pollution, unless con- trolled and reduced, will affect increasing numbers of forest species, influencing their ability to grow and reproduce. On both sides of the Cas- cades, incidence and severity of many native insects and diseases is closely linked to forest management; aware- ness of the effects of various activities on insects and dis- eases is essential to achieving desired forest conditions. Forest management, forest health monitoring, research, and public education are the tools needed to create and maintain the for- ests that are so important to the people of Oregon and Washington. The Future— 85 SELECTED REFERENCES Agee, James K. 1993. Fire ecology of Pacific Northwest forests. Washington, DC: Island Press. 493 p. Bailey, Robert G.; Avers, Peter E.; King, Thomas; IVIcNab, W. Henry, eds. 1994. Ecoregions of the United States (map). Washington, DC: U.S. Geological Survey. Scale 1:7,500,000; colored. Accompanied by a supplementary table of map unit descriptions compiled and edited by McNab, W. Henry, and Bailey, Robert G. Prepared for the U.S. Department of Agriculture, Forest Service. Benedict, Warren V. 1981. History of white pine blister rust control — a personal account. Rep. 355. Wash- ington, DC: U.S. Department of Agriculture, Forest Service. 47 p. Busing, Richard T.; Liegel, Leon H.; LaBau, V.J. [In press]. Overstory mortality as an indicator of forest health in California. Environmental Monitoring and Assessment. 85 p. Dale, John. 1996. California forest health report (in preparation). FPM Rep. San Francisco, CA: U.S. Department of Agriculture, Forest Service. Franklin, J.F.; Dryness, C.T. 1988. Natural vegetation of Oregon and Washington. Corvallis, OR: Oregon State University Press. 452 p. Hessburg, Paul P.; Mitchell, R.G.; Filip, G.M. 1994. Historical and current roles of insects and pathogens in eastern Oregon and Washington forested landscapes. Gen. Tech. Rep. PNW-GTR-327. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 72 p. Liebhold, Andrew M.; MacDonald, William L; Bergdahl, Dale; Mastro, Victor C. 1995. Invasion by exotic forest pests: a threat to forest ecosystems. Forest Science Monograph 30. 49 p. Liegel, Leon H.; Busing, Richard T.; LaBau, V.J. 1996. Evaluating overstory conditions to assess forest health in California. In: Proceedings of the Society of American Foresters national convention; 1995 Oct. 28-Nov. 1; Portland, ME. Bethesda, MD: Journal of American Foresters: 424-425. Liegel, Leon H.; Busing, Richard T.; Solano, Samuel. 1996. Forest health monitoring (FHM) activities in the WEST, 1992-1995. In: Proceedings of the California Forest Pest Council, 44th Annual Meeting; 1995 Nov. 15-16; Rancho Cordova, CA. Sacramento, CA: Department of Forestry and Fire Protection: xi-xix. Mavity, Erika; Stratton, Daniel; Berrang, Paul. 1995. Effects of ozone on several species of plants which are native to the Western United States. Report. Dry Branch, Georgia: U.S. Department of Agriculture, Forest Service, Center for Forest Environmental Studies. 61 p. McNab, W. Henry; Avers, Peter E., comps. 1994. Ecological subregions of the United States: section descrip- tions. Admin. Publ. WO-WSA-5. Washington, DC: U.S. Department of Agriculture, Forest Service. 267 p. Sprengel, Keith, comp. 1995. Forest insect and disease conditions. Pacific Northwest Region, 1994. R6-FID- TP-06-95. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 64 p. Twardus, Dan; Miller-Weeks, Margaret; Gillespie, Andy. 1995. Forest health assessment for the North- eastern Area, 1993. Tech. Rep. NA-TP-01-95. Radnor, PA: U.S. Department of Agriculture, Forest Ser- vice, Northeastern Area. 61 p. U.S. Congress, Office of Technology Assessment. 1993. Harmful non-indigenous species in the United States. Admin. Publ. OTA-F-565. Washington, DC. 391 p. U.S. Department of Agriculture, Forest Service. 1996. Air resource management: what we have been doing. R6-NR-TP-14-96. Portland, OR. U.S. Department of Agriculture Forest Service, Pacific Northwest Region. Wickman, Boyd E. 1992. Forest health in the Blue Mountains: the influence of insects and diseases. Gen. Tech. Rep. PNW-GTR-295. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific North- west Research Station. 15 p. References- APPENDIXA— COMMON AND SCIENTIFIC NAMES The common and scientific names of the trees, diseases, and insects mentioned in this re- port are listed in alphabetical order by common name. An asterisk (*) indicates an exotic (non- native) species. Trees: Alaska yellow-cedar American elm Bigleaf maple Black Cottonwood California black oak Chinkapin Douglas-fir Engelmann spruce Grand fir Hybrid poplar Jeffrey pine Lodgepole pine Mountain hemlock Noble fir Oregon ash Oregon white oak Pacific dogwood Pacific madrone Pacific silver fir Pacific yew Ponderosa pine Port-Orford-cedar Quaking aspen Red alder Sitka spruce Subalpine fir Sugar pine Tanoak Western hemlock Western larch Western redcedar Western white pine Whitebark pine White fir Willow Chamaecyparis nootkatensis Ulmus americana Acer macrophyllum Populus trichocarpa Querciis kelloggii Castanopsis chrysophylla Pseudotsuga menziesii Picea engelmanii Abies grandis Populus spp. Pinusjeffreyi Pinus contorta Tsuga mertensiana Abies procera Fraxinus latifolia Quercus garryana Cornus nuttallii Arbutus menziesii Abies amabalis Taxus brevifolia Pinus ponderosa Chamaecyparis lawsoniana Populus tremuloides Alnus rubra Picea sitchensis Abies lasiocarpa Ptnus lambertiana Lithocarpus densijlorus Tsuga heterophylla Larix occidentalis Thuja plicata Ptnus monticola Ptnus albtcaulis Abies concolor Salix spp. tend X A— 88 Diseases: Annosus root disease Armillaria root disease Black stain root disease * Dogwood anthracnose Douglas-flr dwarf mistletoe * Dutch elm disease Laminated root rot Larch dwarf mistletoe Lodgepole pine dwarf mistletoe * Melampsora leaf rust (hybrid poplar) Mountain hemlock dwarf mistletoe * Port-Orford-cedar root disease Schweinitzii root and butt rot Swiss needle cast Tomentosus root rot Western dwarf mistletoe (ponderosa pine) Western hemlock dwarf mistletoe White fir dwarf mistletoe * White pine blister rust Insects: * Balsam woolly adelgid Douglas-fir beetle Douglas-fir engraver Douglas-fir tussock moth Fir engraver Forest tent caterpillar * Gypsy moth (European or Asian) Hemlock looper Hemlock sawfly Madrone leafminer Mountain pine beetle Oak looper Pandora moth Ponderosa pine cone beetle * Satin moth Sitka spruce weevil Spruce beetle Western pine beetle Western spruce budworm Heterobasidion annosum Armillaria ostoyae Leptographium wagneri Discula destructiva Arceuthobium douglasii Ophiostoma ulmi Phellinus weirii Arceuthobium laricis Arceuthobium americanum Melampsora larici-popultna, M. medusae f.sp. deltoidae Arceuthobium tsugense f.sp. mertensianae Phytophthora lateralis Phaeolus schweinitzii Phaeocryptopus gaumannii lonotus tomentosus Arceuthobium. campylopodum Arceuthobium tsugense f.sp. tsugense Arceuthobium abietinum f.sp. concoloris Cronartium ribicola Adelges piceae Dendroctonus pseudotsugae Scolytus unispinosus Orgyia pseudotsugata Scolytus ventralis Malacosoma disstria Lymantria dispar Lambdtnajiscellaria lugubrasa Neodiprion tsugae Marmara arbutiella Dendroctonus ponderosae Lambdinajiscellaria Coloradia pandora Conophthorus ponderosae Leucoma salicis Pissodes sitchensis Dendroctonus rufipennis Dendroctonus breuicomis Choristoneura occidentalis tendix A — 89 APPENDIX B— COUNTIES IN OREGON AND WASHINGTON tendix B — 90 APPENDIX C— 1995 COOPERATIVE AERIAL SURVEY RESULTS Figure I — Reporting areas for the 1995 Cooperative Aerial Survey m Oregon and Washington. Key: 1 Deschutes NF 15 Umpqua NF 29 Northv/est Oregon 2 Fremont NF 16 Wallowa-Whitman NF 30 Central Oregon 3 Gifford Pinchot NF 17 Wenatchee NF 31 Coos-Douglas 4 Malheur NF 18 Willamette NF 34 Puget Sound 5 Mt. Baker-Snoqualmie NF 20 Winema NF 35 Northeast Washington 6 Mt. Hood NF 21 Colville NF 36 Northv^estWashingtion 7 Ochoco NF 22 Kaniksu NF 38 Southwest Washington 8 Okanogan NF 23 Colville IR 39 Glenwood 9 Olympic NF 24 Umatilla IR 49 Lookout Mtn. 10 Rogue River NF 25 Quinalt IR 51 Crater Lake NP II Siskiyou NF 26 Spokane IR 53 Mt. Rainier NP 12 Siuslaw NF 27 Warm Springs IR 54 Olympic NP 14 Umatilla NF 28 Yakama IR 55 N. Cascades NP 99 Makah IR NF = National Forest IR = Indian Reservation NP = National Park endix C — 9 Table I — 1995 cooperative aerial survey results, arranged by damage ager)t and state Insect species-host State Acres # Trees Area not flown Oregon 115682 0 Area not flown Washington 814274 0 Balsam woolly adelgid Washington 14380 12231 Bear Oregon 740 755 Bear Washington 27225 25454 Black plneleaf scale Oregon 264 0 Blister rust Washington 5731 0 Budmoth on Douglas-flr Oregon 1226 0 Cytospora canker Oregon 366 1466 Douglas-flr beetle Idaho 425 235 Douglas-flr beetle Oregon 37648 22004 Douglas-flr beetle Washington 6128 3917 Douglas-flr beetle engraver Oregon 139 62 Douglas-flr beetle engraver Washington 618 355 Douglas-flr tussock moth Oregon 2931 0 Dying hemlock Washington 51 0 Fir engraver Idaho 14 5 Fir engraver Oregon 534170 429145 Fir engraver Washington 39476 30323 Fire Oregon 1879 0 Fire Washington 174 0 Flatheaded woodborer Oregon 3396 4533 Larch casebearer Oregon 387 0 Larch casebearer Washington 1434 0 Larch needle cast Washington 487 0 Lodgepole needle cast Oregon 387 0 Lodgepole needle cast Washington 1434 0 Maple discoloration Washington 484 0 Mountain pine beetle, lodgepole pine Oregon 104891 396346 Mountain pine beetle, lodgepole pine Washington 123290 346037 Mountain pine beetle, ponderosa pine Idaho 14 6 Mountain pine beetle, ponderosa pine Oregon 128567 101666 Mountain pine beetle, ponderosa pine Washington 58534 52005 Mountain pine beetle, sugar pine California 19 8 Mountain pine beetle, sugar pine Oregon 489 275 Mountain pine beetle, w. white pine Oregon 424 342 Mountain pine beetle, w. white pine Washington 16508 12047 Mountain pine beetle, whitebark pine Oregon 21 5 Mountain pine beetle, whitebark pine Washington 7541 1418 Needleminers on Douglas-flr Oregon 7391 0 Needleminers on lodgepole pine Oregon 6485 0 Oregon pine ips Oregon 4417 3901 Oregon pine ips Washington 1275 1074 Paciflc Madrone decline Washington 68 0 Port Orford cedar root disease Oregon 1885 4237 Root disease Oregon 1054 0 endix C — 92 Insect species-host State Acres # Trees Root disease Washington 227 0 Satin moth Washington 4548 0 Silver fir beetle Washington 762 470 Spruce aphid Oregon 8 0 Spruce aphid Washington 841 0 Spruce beetle Oregon 4874 1486 Spruce beetle Washington 4679 5461 Water Oregon 10 0 Water Washington 1260 0 Western balsam bark beetle Idaho 23 20 Western balsam bark beetle Oregon 6858 5484 Western balsam bark beetle Washington 6423 3662 Western pine beetle Idaho 221 25 Western pine beetle Oregon 34100 18572 Western pine beetle Washington 18021 8993 Western pine beetle, small trees Oregon 1550 3395 Western pine beetle, small trees Washington 26881 15521 Western spruce budworm Oregon 14873 0 Western spruce budworm Washington 175104 0 Wind Washington 1038 0 •endix C— 93 Table 2 — 1995 cooperative aerial survey results, for ir)sects only, arranged by state, reporting area, and insect state Reporting Area Insect species-host Acres # Trees California Rogue River National Forest Mountain pine beetle, sugar pine 19 8 Idaho Wallowa- Whitman National Forest Douglas-fir beeUe 425 235 Idaho Wallowa- Whitman National Forest Fir engraver 14 5 Idaho Wallowa- Whitman National Forest Mountain pine beetle, ponderosa pine 14 6 Idaho Wallowa-Whitman National Forest Western balsam bark beetle 23 20 Idaho Wallowa- Whitman National Forest Western pine beetle 221 25 Oregon Central Oregon Douglas-fir beetle 295 132 Oregon Central Oregon Fir engraver 31 15 Oregon Central Oregon Mountain pine beetle, ponderosa pine 1674 1199 Oregon Central Oregon Oregon pine ips 1254 453 Oregon Central Oregon Western pine beetle 12 5 Oregon Coos-Douglas Douglas-fir beetle 81 70 Oregon Coos-Douglas Fir engraver 61 125 Oregon Coos-Douglas Flatheaded woodborer 8 10 Oregon Coos-Douglas Mountain pine beetle, ponderosa pine 7 10 Oregon Coos-Douglas Mountain pine beetle, sugar pine 15 16 Oregon Crater Lake National Park Douglas-fir beetle 135 50 Oregon Crater Lake National Park Fir engraver 1243 368 Oregon Crater Lake National Park Mountain pine beetle, lodgepole pine 440 286 Oregon Deschutes National Forest Douglas-fir beetle 40 37 Oregon Deschutes National Forest Fir engraver 17639 29054 Oregon Deschutes National Forest Mountain pine beetle, lodgepole pine 77747 322592 Oregon Deschutes National Forest Mountain pine beetle, ponderosa pine 7237 6489 Oregon Deschutes National Forest Mountain pine beetle, w. white pine 42 100 Oregon Deschutes National Forest Western pine beetle 1097 530 Oregon Fremont National Forest Douglas-fir beetle 6 5 Oregon Fremont National Forest Fir engraver 311424 267409 Oregon Fremont National Forest Mountain pine beetle, lodgepole pine 7906 40192 Oregon Fremont National Forest Mountain pine beetle, ponderosa pine 21592 12539 Oregon Fremont National Forest Needleminers on lodgepole pine 5863 0 Oregon Fremont National Forest Western pine beetle 7527 5511 Oregon Malheur National Forest Douglas-fir beetle 826 889 Oregon Malheur National Forest Douglas-flr tussock moth 2931 0 Oregon Malheur National Forest Fir engraver 2916 2053 Oregon Malheur National Forest Mountain pine beetle, lodgepole pine 2258 1238 Oregon Malheur National Forest Mountain pine beetle, ponderosa pine 7314 8930 Oregon Malheur National Forest Oregon pine ips 163 155 Oregon Mcilheur National Forest Spruce beetle 87 50 Oregon Malheur National Forest Western pine beetle 2149 2405 Oregon Mt. Hood National Forest Douglas-fir beetle 424 351 Oregon Mt. Hood National Forest Douglas-fir beetle engraver 8 5 Oregon Mt. Hood National Forest Fir engraver 10299 8647 Oregon Mt. Hood National Forest Mountain pine beetle, lodgepole pine 221 235 Oregon Mt. Hood National Forest Mountain pine beetle, ponderosa pine 10435 8359 Oregon Mt. Hood National Forest Mountain pine beetle, w. white pine 228 120 Oregon Mt. Hood National Forest Oregon pine ips 114 150 tendix C — 94 state Reporting Area Insect species-host Acres # Trees Oregon Mt. Hood National Forest Western pine beetle 462 315 Oregon Mt. Hood National Forest Western pine beetle, small trees 46 30 Oregon Mt. Hood National Forest Western spruce budworm 14873 0 Oregon Northwest Oregon Douglas-fir beetle 263 319 Oregon Northwest Oregon Fir engraver 82 55 Oregon Northwest Oregon Spruce aphid 8 0 Oregon Ochoco Nationeil Forest Douglas-fir beetle 1812 3179 Oregon Ochoco National Forest Fir engraver 7041 3047 Oregon Ochoco National Forest Mountain pine beetle, ponderosa pine 26806 18466 Oregon Ochoco National Forest Oregon pine ips 433 225 Oregon Ochoco National Forest Western pine beetle 12254 4644 Oregon Ochoco National Forest Western pine beetle, small trees 353 376 Oregon Rogue River National Forest Douglas-fir beeUe 54 55 Oregon Rogue River National Forest Fir engraver 60398 44079 Oregon Rogue River National Forest Flatheaded woodborer 3309 4463 Oregon Rogue River National Forest Mountain pine beetle, lodgepole pine 290 673 Oregon Rogue River National Forest Mountain pine beetle, ponderosa pine 3134 3078 Oregon Rogue River National Forest Mountain pine beetle, sugar pine 248 119 Oregon Rogue River National Forest Mountain pine beetle, w. white pine 14 10 Oregon Rogue River National Forest Mountain pine beetle, whitebark pine 21 5 Oregon Rogue River National Forest Oregon pine ips 713 1755 Oregon Rogue River National Forest Western pine beetle 3734 2946 Oregon Rogue River National Forest Western pine beetle, small trees 1077 2914 Oregon Siskiyou National Forest Douglas-fir beetle 37 69 Oregon Siskiyou National Forest Fir engraver 2555 1590 Oregon Siskiyou National Forest Flatheaded woodborer 79 60 Oregon Siskiyou National Forest Mountain pine beetle, ponderosa pine 143 160 Oregon Siskiyou National Forest Mountain pine beetle, sugar pine 186 120 Oregon Siskiyou National Forest Oregon pine ips 12 35 Oregon Siskiyou National Forest Western pine beetle 1063 775 Oregon Siskiyou National Forest Western pine beetle, small trees 74 75 Oregon Siuslaw National Forest Budmoth on Douglas-fir 1226 0 Oregon Siuslaw National Forest Douglas-fir beetle 138 205 Oregon Umatilla National Forest Douglas-fir beetle 19045 8455 Oregon Umatilla National Forest Fir engraver 3632 1959 Oregon Umatilla National Forest Mountain pine beetle, ponderosa pine 7712 7557 Oregon Umatilla National Forest Needleminers on Douglas-fir 2580 0 Oregon Umatilla National Forest Oregon pine ips 1507 988 Oregon Umatilla National Forest Spruce beetle 59 25 Oregon Umatilla National Forest Western balsam bark beetle 5003 3352 Oregon Umatilla National Forest Western pine beetle 2222 429 Oregon Umatilla Indian Reservation Douglas-fir beetle 558 223 Oregon Umatilla Indian Reservation Fir engraver 40 25 Oregon UmatUla Indian Reservation Mountain pine beetle, ponderosa pine 345 540 Oregon Umatilla Indian Reservation Western pine beetle 147 25 Oregon Umpqua National Forest Douglas-fir beetle 115 110 Oregon Umpqua Nationsd Forest Fir engraver 146 119 Oregon Umpqua National Forest Mountain pine beetle, lodgepole pine 135 115 JUL endix C— 95 state Reporting Area Insect species-host Acres # Trees Oregon Umpqua National Forest Mountain pine beetle, sugar pine 35 19 Oregon Umpqua National Forest Mountain pine beetle, w. white pine 13 10 Oregon Umpqua National Forest Western pine beetie 11 10 Oregon Wallowa-Whitman National Forest Douglas-fir beetie 12876 7207 Oregon Wallowa- Whitman National Forest Douglas-fir beetie engraver 9 7 Oregon Wallowa-Whitman National Forest Fir engraver 3279 1594 Oregon Wallowa- Whitman National Forest Larch casebearer 387 0 Oregon Wallowa-Whitman National Forest Lxjdgepole needle cast 387 0 Oregon Wallowa-Whitman National Forest Mountain pine beetle, lodgepole : pine 278 151 Oregon Wallowa-Whitman National Forest Mountain pine beetle, ponderosa pine 14645 20169 Oregon Wallowa-Whitman National Forest Mountain pine beetle, w. white pine 12 5 Oregon Wallowa-Whitman National Forest Needleminers on Douglas-fir 4811 0 Oregon Wallowa-Whitman National Forest Oregon pine ips 185 30 Oregon Wallowa-Whitman National Forest Spruce beetie 4728 1411 Oregon Wallowa-Whitman National Forest Western balsam bark beetie 1855 2132 Oregon Wallowa-Whitman National Forest Western pine beetie 2432 566 Oregon Warm Springs Indian Reservation Douglas-flr beetie 263 123 Oregon Warm Springs Indian Reservation Fir engraver 4480 3946 Oregon Warm Springs Indian Reservation Mountain pine beetie, lodgepole ; pine 12190 28219 Oregon Warm Springs Indian Reservation Mountain pine beetle, ponderosa pine 740 471 Oregon Warm Springs Indian Reservation Mountain pine beetle, w. white ptne 5 5 Oregon Warm Springs Indian Reservation Oregon pine ips 32 90 Oregon Warm Springs Indian Reservation Western pine beetie 134 40 Oregon Willamette National Forest Douglas-flr beetie 469 495 Oregon Willamette National Forest Douglas-flr beetie engraver 122 50 Oregon Willamette National Forest Fir engraver 1016 770 Oregon Willamette National Forest Mountain pine beetie, lodgepole pine 2225 1271 Oregon Willamette National Forest Mountciin pine beetie, w. white pine 93 87 Oregon Willamette National Forest Oregon pine ips 4 20 Oregon Willamette National Forest Western pine beetie 8 5 Oregon Winema National Forest Black pineleaf scale 264 0 Oregon Wlnema National Forest Douglas-flr beetie 211 30 Oregon Winema National Forest Fir engraver 107888 64290 Oregon Winema National Forest Mountain pine beetie, lodgepole -. pine 1201 1374 Oregon Winema National Forest Mountain pine beetie, ponderosa pine 26783 13699 Oregon Winema National Forest Mountain pine beetle, sugar pine 5 1 Oregon Winema National Forest Mountain pine beetle, w. white pine 17 5 Oregon Winema National Forest Needleminers on lodgepole pine 622 0 Oregon Winema National Forest Western pine beetie 848 366 Washington Colville National Forest Douglas-flr beetie 207 120 Washington Colville National Forest Douglas-flr beetie engraver 242 165 Washington Colville National Forest Fir engraver 7194 5213 Washington Colville National Forest Larch casebearer 616 0 Washington Colville National Forest Lodgepole needle cast 616 0 Washington Colville National Forest Mountain pine beetie, lodgepole ; ptne 18527 18734 Washington Colville National Forest Mountain pine beetie, ponderosa ptne 11984 8837 Washington Colville National Forest Mountain pine beetie, w. white pine 1616 711 Washington Colville National Forest Mountain pine beetie, whitebeirk pine 57 50 1 Appendix C — 96 I state Reporting Area Insect species-host Acres # Trees Washington Colvllle NaUonal Forest Oregon pine ips 485 289 Washington Colville National Forest Satin moth 643 0 Washington Colvllle National Forest Silver fir beeUe 517 276 Washington Colvllle National Forest Spruce beetle 94 30 Washington Colvllle NaUonal Forest Western balsam bark beeUe 2901 1648 Washington Colvllle National Forest Western pine beetle 3082 1286 Washington Colvllle National Forest Western pine beetle, small trees 779 655 Washington Colvllle National Forest Western spruce budworm 4034 0 Washington Colville Indian Reservation Douglas-flr beeUe 113 55 Washington Colville Indian Reservation Douglas-flr beeUe engraver 12 10 Washington Colville Indian Reservation Fir engraver 1849 1506 Washington Colvllle Indian Reservation Mountain pine beetle, lodgepole ; pine 5035 6148 Washington Colville Indian Reservation Mountain pine beeUe, ponderosa . pine 10495 9644 Washington CoMUe Indian Reservation Oregon pine ips 210 385 Washington Colvllle Indian Reservation SaUn moth 949 0 Washington Colville Indiem Reservation Silver fir beeUe 182 99 Washington Colville Indian Reservation Western balsam bark beeUe 146 75 Washington Colville Indian Reservation Western pine beeUe 3273 1538 Washington Colville Indian Reservation Western pine beeUe, small trees 632 647 Washington Colville Indian Reservation Western spruce budworm 936 0 Washington Gifford-Pinchot National Forest Balsam woolly adelgld 1995 886 Washington Gifford-Plnchot National Forest Douglas-fir beeUe 846 534 Washington Gifford-Pinchot National Forest Fir engraver 1168 536 Washington Gifford-Pinchot NaUonal Forest Mountain pine beeUe, lodgepole ; pine 7 5 Washington Gifford-Pinchot National Forest Mountain pine beeUe, ponderosa I pine 48 35 Washington Gifford-Pinchot National Forest Mountain pine beeUe, w. white pine 145 70 Washington Gifford-Pinchot NaUonal Forest Mountain pine beeUe, whitebark pine 302 4 Washington Gifford-Pinchot NaUonal Forest Oregon pine ips 61 10 Washington Gifford-Pinchot NaUonal Forest Silver fir beeUe 37 75 Washington Gifford-Pinchot NaUonal Forest Western balsam bark beetle 196 40 Washington Gifford-Pinchot NaUonal Forest Western pine beeUe 28 30 Washington Gifford-Pinchot National Forest Western spruce budworm 15407 0 Washington Glenwood Douglas-fir beeUe 434 115 Washington Glenwood Fir engraver 312 315 Washington Glenwood Mountain pine beeUe, ponderosa 1 pine 5454 5184 Washington Glenwood Oregon pine ips 237 130 Washington Glenwood Spruce beetle 39 2 Washington Glenwood Western pine beetle 2067 911 Washington Glenwood Western pine beeUe, small trees 19187 9051 Washington Glenwood Western spruce budworm 29028 0 Washington Kaniksu National Forest Douglas-fir beeUe 30 15 Washington Kaniksu NaUonal Forest Fir engraver 1963 1431 Washington Kaniksu NaUonal Forest Larch casebesirer 120 0 Washington Kaniksu NaUonal Forest Lodgepole needle cast 120 0 Washington Kaniksu National Forest Mountain pine beetle, lodgepole pine 2299 2174 Washington Kaniksu NaUonal Forest Mountain pine beetle, ponderosa ; pine 718 551 Washington Kcinlksu NaUonal Forest Mountain pine beeUe, w. white pine 3258 3907 Washington Kaniksu NaUonal Forest Spruce beetle 77 20 endix C — 97 state Reporting Area Insect species-host Acres # Trees Washington Kanlksu National Forest Western balsam bark beetle 124 150 Washington Kanlksu National Forest Western pine beetle 31 20 Washington Makah Indian Reservation Douglas-fir beetle 8 5 Washington Mt. Baker-Snoqualmie National Forest Balsam woolly adelgld 3975 3314 Washington Mt. Baker-Snoqualmle National Forest Douglas-fir beetle 1050 581 Washington Mt. Baker-Snoqualmie National Forest Douglas-fir beetle engraver 137 35 Washington Mt. Baker-Snoqualmle National Forest Fir engraver 347 174 Washington Mt. Baker-Snoqualmie National Forest Mountain pine beetle, lodgepole pine 332 1534 Washington Mt. Baker-Snoqualmle National Forest Mountain pine beetle, ponderosa pine 209 125 Washington Mt. Baker-Snoqualmle National Forest Mountain pine beetle, w. white ] pine 454 260 Washington Mt. Baker-Snoqualmle National Forest Mountain pine beetle, whitebark pine 59 85 Washington Mt. Baker-Snoqualmle National Forest Silver fir beetle 26 20 Washington Mt. Baker-Snoqualmle National Forest Spruce beetle 2336 4506 Washington Mt. Baker-Snoqualmie National Forest Western balsam bark beetle 150 115 Washington Mt. Baker-Snoqualmie National Forest Western pine beetle 332 270 Washington Mt. Rainier NaUonal Park Balsam woolly adelgld 2880 3600 Washington North Cascades National Park Balsam woolly adelgld 57 80 Washington North Cascades National Park Douglas-fir beetle 54 60 Washington North Cascades National Park Fir engraver 447 235 Washington North Cascades National Park Larch needle cast 59 0 Washington North Cascades National Park Mountain pine beetle, lodgepole pine 69 150 Washington North Cascades National Park Mountain pine beetle, ponderosa pine 258 220 Washington North Cascades National Park Mountain pine beetle, w. white ] pine 274 155 Washington North Cascades National Park Mountain pine beetle, whitebark pine 48 34 Washington North Cascades National Park Spruce beetle 99 55 Washington North Cascades National Park Western balsam bark beetle 80 80 Washington North Cascades National Park Western pine beetle 160 75 Washington Northeast Washington Douglas-fir beetle 91 90 Washington Northeast Washington Douglas-fir beetle engraver 61 65 Washington Northeast Washington Fir engraver 5887 7251 Washington Northeast Washington Larch casebearer 698 0 Washington Northeast Washington Lodgepole needle cast 698 0 Washington Northeast Washington Mountain pine beetle, lodgepole pine 611 430 Washington Northeast Washington Mountain pine beetle, ponderosa pine 9842 10687 Washington Northeast Washington Mountain pine beetle, w. white ] pine 118 75 Washington Northeast Washington Oregon pine Ips 129 125 Washington Northeast Washington Satin moth 20 0 Washington Northeast Washington Western pine beetle 1270 821 Washington Northeast Washington Western pine beetle, small trees 580 725 Washington Nortwest Washington Douglas-fir beetle 367 292 Washington Nortwest Washington Douglas-fir beetle engraver 36 10 Washington Nortwest Washington Mountain pine beetle, lodgepole pine 90 159 Washington Okanogan National Forest Douglas-fir beetle 213 110 Washington Okanogan National Forest Douglas-fir beetle engraver 127 65 Washington Okanogan National Forest Fir engraver 2656 1373 Washington Okanogan National Forest Mountain pine beetle, lodgepole pine 90138 310023 Washington Okanogan National Forest Mountain pine beetle, ponderosa pine 5618 4701 Washington Okanogan National Forest Mountain pine beetle, w. white ] pine 1295 820 App .endix C— 98 state Reporting Area Insect species-host Acres # Trees Washington Okanogan National Forest Mountain pine beetle, whltebark : pine 901 390 Washington Okanogan National Forest Oregon pine Ips 55 30 Washington Okanogan National Forest Satin moth 2273 0 Washington Okanogan National Forest Spruce aphid 33 0 Washington Okanogan National Forest Spruce beetle 876 435 Washington Okanogan National Forest Western balsam bark beetle 1228 600 Washington Okanogan National Forest Western pine beetle 1560 597 Washington Okanogan National Forest Western pine beetle, small trees 30 30 Washington Olympic National Forest Balsam woolly adelgld 482 335 Washington Olympic National Forest Douglas-flr beeUe 488 308 Washington Olympic National Forest Fir engraver 34 21 Washington Olympic National Forest Mountain pine beetle, lodgepole pine 64 35 Washington Olympic National Forest Mountain pine beetle, w. white pine 339 225 Washington Olympic National Forest Spruce aphid 83 0 Washington Olympic National Park Balsam woolly adelgid 3400 3110 Washington Olympic National Park Douglas-flr beetle 34 25 Washington Olympic National Park Fir engraver 26 14 Washington Olympic National Park Mountain pine beetle, w. white pine 1192 755 Washington Olympic National Park Mountain pine beetle, whltebcirk pine 38 20 Washington Puget Sound Douglas-flr beetle 253 195 Washington Puget Sound Douglas-flr beetle engraver 3 5 Washington Puget Sound Mountain pine beetle, w. white pine 28 10 Washington Qulnalt Indian Reservation Fir engraver 36 25 Washington Southwest Washington Douglas-flr beetle 210 171 Washington Southwest Washington Mountain pine beetle, lodgepole pine 12 20 Washington Southwest Washington Spruce aphid 725 0 Washington Spokane Indian Reservation Douglas-flr beetle 105 90 Washington Spokane Indian Reservation Fir engraver 337 410 Washington Spokane Indian Reservation Mountain pine beede, lodgepole pine 13 10 Washington Spokane Indian Reservation Mountain pine beede, ponderosa pine 1103 1416 Washington Spokane Indian Reservation Oregon pine ips 6 5 Washington Spokane Indian Reservation Spruce beede 21 5 Washington Spokane Indian Reservation Western pine beede 208 80 Washington Spokane Indian Reservation Western pine beetle, small trees 174 230 Washington Umatilla National Forest Douglas-flr beeUe 791 490 Washington Umatilla National Forest Fir engraver 1812 1606 Washington Umatilla National Forest Mountain pine beede, lodgepole pine 55 120 Washington Umatilla National Forest Mountain pine beede, ponderosa pine 1472 2152 Washington UmaUUa National Forest Oregon pine ips 45 25 Washington Umatilla NaUonal Forest Spruce beede 22 5 Washington Umatilla National Forest Western balsam bark beede 438 370 Washington Umatilla National Forest Western pine beede 455 145 Washington Wenatchee National Forest Balsam woolly adelgld 1582 901 Washington Wenatchee National Forest Douglas-flr beede 812 646 Washington Wenatchee National Forest Fir engraver 14706 8583 Washington Wenatchee National Forest Larch needle cast 428 0 Washington Wenatchee National Forest Mountain pine beede, lodgepole pine 1574 1789 Washington Wenatchee National Forest Mountain pine beede, ponderosa pine 7418 6390 endix C — 99 state Reporting Area Insect species-host Acres # Trees Washington Wenatchee National Forest Mountain pine beetle, w. white pine 7746 4964 Washington Wenatchee National Forest Mountain pine beetle, whltebark pine 5327 760 Washington Wenatchee National Forest Oregon pine ips 47 75 Washington Wenatchee National Forest Satin moth 663 0 Washington Wenatchee National Forest Spruce beetle 646 325 Washington Wenatchee National Forest Western balsam bark beetle 1160 584 Washington Wenatchee National Forest Western pine beetle 4805 2810 Washington Wenatchee National Forest Western pine beetle, small trees 3525 2678 Washington Wenatchee National Forest Western spruce budworm 132 0 Washington Yakima Indian Reservation Balsam woolly adelgid 9 5 Washington Yakima Indian Reservation Douglas-fir beetle 22 15 Washington Yakima Indian Reservation Fir engraver 702 1630 Washington Yakima Indian Reservation Mountain pine beetle, lodgepole ] pine 4464 4706 Washington Ysikima Indian Reservation Mountain pine beetle, ponderosa pine 3915 2063 Washington Yciklma Indian Reservation Mountain pine beetle, w. white pine 43 95 Washington Yakima Indian Reservation Mountain pine beetle, whltebark pine 809 75 Washington Yakima Indian Reservation Spruce beetle 469 78 Washington Yakima Indian Reservation Western pine beetle 750 410 Washington Yakima Indian Reservation Western pine beetle, small trees 1974 1505 Washington Yakima Indian Reservation Western spruce budworm 125567 0 lendix C — 100 APPENDIX D— THE NATIONAL FOREST HEALTH MONITORING PROGRAM The national Forest Health Monitoring Program (often abbreviated as FHM) began in 1990 in 10 northeastern states. It was a cooperative effort between the USDA Forest Service, the U.S. Environmental Protection Agency (EPA), state forestry agencies, and the National Asso- ciation of State Foresters. Today, cooperators also include the U.S. Department of the Interior's Bureau of Land Management, Fish and Wildlife Service, and National Park Service; the USDA National Resource Conservation Service; and state forestry organizations in eight additional states. The main objectives of this program are to determine the status, trends, and condition of forests nationwide. The national Forest Health Monitoring West Coast Administrative Region includes Califor- nia, Hawaii, and Alaska plus Oregon and Washington. Operational field work began in Califor- nia in 1992 when 55 forested plots were measured across the state. A different set of about 50 forested plots were measured yearly from 1993 to 1995. This complete 4-year set of data com- prises the baseline condition for California forests. Each baseline year is a separate estimate of forest conditions in the state. Remeasurement of California plots began in 1996. Another field effort in the West Coast region was a pilot study for western Oregon and Washington (described in chapter 5), in which 25 plots in Douglas-fir habitat were measured. Baseline plots in Oregon and Washington will be established in 1997. Forest Health Monitoring Regions Hawaii endix D — 01 Three separate but parallel activities comprise the Forest Health Monitoring Program. In detection monitoring, field crews measure selected biotic and abiotic features called indica- tors of forest condition during a baseline period. These same features are then remeasured at yearly or other intervals. Changes between the baseline and remeasurement conditions indi- cate a response to natural forest change or ecosystem disturbance. The ecosystem indicators are analogous to general blood pressure, pulse, and blood chemistry data recorded for people in routine medical exams. Infant, juvenile, adult, and mature age groups have certain indica- tor values for normal health. Values outside the normal ranges indicate something is amiss and should be checked by a medical specialist. Evaluation monitoring begins when the cause of a significant and detected change is un- known. Activities include intensive field sampling and combined interpretations by ecologists, entomologists, hydrologists, pathologists, silviculturists, and others. These resource special- ists are like the heart, kidney, lung, and other medical experts who are asked to diagnose blood chemistry results that fall outside of normal values or that result from traumatic injury. Intensive site ecosystem monitoring combines knowledge from evaluation monitoring and results from long-term watershed-scale research at a few sites with diverse forest types and biomes typical of those found in the United States. The best example in the West is the H.J. Andrews Experimental Forest near Blue River, Oregon, where forest research work has been conducted since the 1940s. Combining information from all three monitoring activities allows predicting where and how future ecosystem changes might take place under given environmental and management con- ditions. lendix D- Index air pollution 11, 19-21, 30, 46, 72, 75-76, 82, 84, 85 air quality. See air pollution Alaska yellow-cedar 39, 88 American elm 62, 88 annosus root disease 29, 36. 38, 53-54, 89 armillaria root disease 27, 32, 36, 40, 54, 83, 89 B balsam woolly adelgid 16, 32, 50-51, 89, 92, 97- 100 bark beetles 10,12-14,26, 32-33, 35-38, 40, 42-43, 47-48, 51, 54, 56-58, 62, 79-81, 85 basal area 69 bear damage 22, 28-29 bigleaf maple 25, 30, 45, 51, 88 bird community index. See songbird habitat bioindicators. See indicators black Cottonwood 30, 33, 38, 88 black stain root disease 27, 40, 83, 89 Blue Mountains 4, 13, 15, 33-38 California black oak 39, 88 canker diseases 3 1 , 34 chinkapin 39, 88 crown dieback 70-71 defoliators 10, 32-33, 35, 49-50, 54-55, 58, 62-64, 82 detection monitoring 102 Douglas-fir 7, 9-10, 25-29, 33-36, 38-39, 43, 45, 47-49, 53-56, 67, 69, 82,88 Douglas-fir beetle 26, 35-36, 43, 47-48, 56, 89, 92, 94-100 Douglas-fir dwarf mistletoe 34-35, 40-41, 55-56, 89 Douglas-fir engraver 89 Douglas-fir tussock moth 38, 79, 82, 89, 92, 94 drought 11, 15, 26, 30-37, 39, 42-43, 47, 51-52, 56, 58, 64, 79-80, 82, 84 dwarf mistletoes 10,29,34- 35, 40-41, 49, 55-56 Eastern Cascades 4, 79-82 Eastern Cascades, Oregon 4, 33-38 Eastern Cascades, Washing- ton 4, 53-58 Engelmann spruce 25, 38, 45, 53, 88 exotic pests 16-19, 29, 32, 41-43, 50, 52, 58. 62-64, 82. 84-85 fir engraver 35-36. 89,92, 94-100 fire 6-12, 25-26. 30, 32-41, 45, 51, 53-55, 58, 61, 76, 79-82, 84, 85, 92 fire suppression 8-10,32- 34, 36-38, 53-55, 79, 84 fire exclusion. See fire sup- pression Hoods 34 foliage disease 27-28, 32, 47-49, 52 foliage transparency 70-72, 77 forest health monitoring 2 1 - 23,66-78,85, 101-102 Forest Health Monitoring Program 22, 66-77, 101-102 forest tent caterpillar 52, 89 grand fir 9. 16, 25, 30, 32- 35, 37, 50, 53-56, 88 grazing 6, 9. 11. 38. 57 gypsy moth 16. 19. 62-64, 89 H hazard tree 46-47, 61, 64 hemlock looper 9. 49-50. 82, 89 hemlock sawfly 29. 89 hybrid poplar 32, 88 I indicators 2, 19, 21, 22, 66- 67, 70, 73-74, 76-77. 102 Intensive site ecosystem monitoring 102 introduced pests. See exotic pests J Jeffrey pine 39, 41, 88 K raamath Mountains 4. 39-43 laminated root rot 26-27, 36, 40, 47, 53, 61. 89 larch dwarf mistletoe 34, 55, 89 lichens 19-22, 30, 46, 68, 75-77 lodgepole pine 6, 10-11,25, 33. 35, 37-38, 40-41. 53, 55. 57, 80-81, 88, 92, 94-100 lodgepole pine dwarf mistle- toe 35, 40, 55, 89 low temperature injury 14- 15, 31 Index— 104 M Puget Trough 4, 45-52 U madrone leafminer 52, 89 melampsora leaf rust 32,89 mixed conifer 10, 33-37, 43, 53-56, 68, 79 Modoc Plateau 4, 33-38 monitoring. See forest health monitoring mortiality 11-13, 67 mountain hemlock 25, 39, 41, 45, 49, 53, 88 mountain hemlock dwarf mistletoe 41, 49, 89 mountain pine beetle 1 1 , 37-38, 42-43, 51, 56, 57, 81, 89, 92, 94-100 N noble fir 6, 25, 45, 88 Okanogan Highlands 4, 53- 58 Oregon 24-43 Oregon ash 30, 88 Oregon Coast Range 4, 25- 29 Oregon white oak 30, 32, 39, 64, 88 ozone 19-21, 30, 46, 84 Pacific dogwood 52, 64, 88 Pacific madrone 39, 52, 88 Pacific silver fir 25, 39, 45, 88 Pacific yew 25, 88 pandora moth 38, 61, 89 poles 68, 69 ponderosa pine 6-7, 10, 12, 30-38, 41, 43, 53-58, 82, 88 ponderosa pine cone beetle 32, 89 Port-Orford-cedar 18, 19, 39, 41-42, 84, 88 Port-Orford-cedar root disease 18, 19, 41-42, 84, 89 quaking aspen 33, 38, 39, 58, 80, 88 red alder 25, 30, 45, 51, 52, 88 risk rating 23 root disease 10, 12, 18-19, 26-27, 29, 32, 35-36, 40-43, 46, 53-54, 56, 58, 61, 79-80, 82-84, 93 root rot. See root disease sapling crown vigor 69, 70 saplings 68-70, 72, 77 satin moth 58, 89, 93, 97- 100 sawtimber 68, 69, 77 Schweinitzii root and butt rot 54, 89 seedlings 68, 83-84 site characteristics 67-69 Sitka spruce 25, 29, 45, 88 Sitka spruce weevil 29, 89 songbird habitat 67, 74, 76- 77 Southern Cascades 4, 39-43 spruce beetle 38, 84-85, 89, 93-100 stand characteristics 68 stem decay 26, 34, 46 subalpine fir 6, 25, 45, 54, 88 subplots 68, 73-74, 77 sugar pine 17, 25, 33, 39, 42-43, 84-85, 88, 92, 94-96 Swiss needle cast 27-28, 47- 49, 82, 89 true fir. See grand fir and white fir understory vegetation 22, 68-69, 76 urban forest health 60-65 vegetation change 6-10 vegetation structure 74, 77 w Washington 44-58 Washington Coast Range 4, 45-52 weather 13-16, 18, 21, 33- 34, 52, 60 see also drought, floods, low temperature injury, windthrow, winter wind damage Western Cascades 4, 82-84 Western Cascades, Oregon 4, 25-29 Western Cascades, Washing- ton 4, 45-52 western hemlock dwarf mistletoe 49, 89 western larch 10, 12, 33-34, 37, 53-55, 82 western pine beetle 35, 58, 89, 93-100 western redcedar 25, 28, 30, 45, 69, 88 western spruce budworm 11-13, 35, 37, 54-56, 79, 82, 89, 93, 95, 97, 100 white fir 33, 35-36, 39, 41, 43, 50, 88, white fir dwarf mistletoe 34, 89 white pine blister rust 1 6- 17. 19, 29. 42, 51, 84, 89 whitebark pine 17, 25, 42, 45, 51, 53, 85, 88 Willamette Valley 4, 25-29 willow 33, 45, 88 windthrow 26-27, 34, 38, 45, 47-48, 56, 61 winter wind injury 1 5 ndex— 05 Campbell, Sally; Liegel, Leon, tech. coords. 1996. Disturbance and forest health in Oregon and Washington. Gen. Tech. Rep. PNW- GTR-381. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station and Pacific Northwest Region; Oregon Department of Forestry; and Washington Depart- ment of Natural Resources. 105 p. The scope and intensity of disturbance by such agents as fire, insects, diseases, air pollution, and weather in Pacific Northwest forests suggests that forest health has declined in recent years in many areas. The most significant disturbances and causes of tree mortality or decline in Oregon and Washington are presented and illustrated. We discuss the interrelations of disturbance with forest management activities and the effect on native trees and suggest some solutions for reducing the severity of disturbance. One chapter reports on a forest health monitoring pilot project. The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of multiple use management of the Nation's forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives — as directed by Congress — to provide increasingly greater service to a growing Nation. The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status. (Not all prohibited bases apply to all pro- grams.) Persons with disabilities who require alter- native means of communication of program informa- tion (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720-2791 . To file a complaint, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, DC 20250, or call (202) 720-7327 (voice) or (202) 720- 11 27 (TDD). USDA is an equal employment opportu- nity employer. Pacific Northwest Research Station 333 S.W. First Avenue RO. Box 3890 Portland, Oregon 97208-3890 » t ;. "^^ W ,' .■^ z^y. i /t: ,i!j?v :^i^*- ■ ■t,.«a •*■ I* -A :.-:.■ ■>■ V*, *J^'' '''■%-:^^'.