Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. Summary Report United States Department of Agriculture Forest Service Northeastern Area Forest Health Monitoring New England Northeastern Forest Experiment Station IddO NE-INF-94-91 7 ro CO > -< 1 n== Acknowledgments Forest Health Monitoring is truly a cooperative effort. Besides the numerous individuals that formed the Area and Station partnership, many other individuals of numerous agencies worked to make the program a success. The U.S. Environmental Protection Agency provided portable data recorders and technical support for the equipment. The State Foresters from Maine, New Hampshire, Vermont, Massachusetts, Connecticut, and Rhode Island gave their critical support to the program and provided the services of their staffs to help develop the program and collect the field data. Forestry Canada helped with critical decisions and their Acid Rain National Early Warning System (ARNEWS) was one model we studied in the design of Forest Health Monitoring. Without the support and participation of all, it is unlikely that Forest Health Monitoring in 1990 would have been the success it proved to be. , Summary Report 8^ Forest Health Monitoring New England Robert xjErooks, (^.S. Department of Agriculture, Forest Service, Amherst, Massachusetts^ Margare^^Miller- Weeks, U.S. Department of Agriculture, Forest Service, Durham, New Hampshire William jBurkman, U.S. Department of Agriculture, Forest Service, Radnor, Pennsylvania Northeastern Area Association of State Foresters and USDA, Forest Service Northeastern Area Northeastern Forest Experiment Station in cooperation with U.S. Environmental Protection Agency Forestry Canada May 1991 NE-INF-94-91 1990 Summary Report Forest Health Monitoring New England The six-state New Engleind region is estimated to be over 80 percent forested. With a total land area of more than 40 million acres, forestland comprises over 32 miUion acres. The predominance of forestland occurs throughout New England, with Maine most extensively forested (89 percent) and forestland in southern New England exceeding 60 percent of total land area. New England Forest Resource Over 85 percent of New England forests are classified as one of four major forest-tj^ groups: White Pine, Spruce-Fir, Oak-Hickory, and Northern Hardwoods. Across New England, 76 tree species have been recorded on forest survey plots. The most common conifers are balsam fir and red spruce and the most common hardwood species is red maple. The New England forest is maturing, with 46 percent presently classified as sawtimber-sized stands (trees generally larger than 10 or 11 inches in diameter) and presumably containing the oldest trees. The area of sawtimber-sized stands increased 36 percent fi-om the surveys of the 1970's. Concurrently, smaller poletimber-sized stands (trees 5 to 10 or 11 inches in diameter) and seedling-saphng-sized stands (trees less than 5 inches in diameter) decreased, respectively, 8 and 51 percent in area. The forests of New England have been, and continue to be, exposed to a broad range of stressors, both natural and human-caused. Natural stressors include weather extremes, forest insects, and pathogens. Human-caused stressors include land-use change, air pollution (for example, ozone), and acidic deposition. A new but imsubstantiated concern is global climate change due to generation of gases that create a "greenhouse effect." The predominance of forests in New England, their importance for recreation, water, £ind wood products, and the increased awareness of stress upon forest ecosystems have resulted in a demand to address concerns about forest "health" and human influences. Forest Health Monitoring: New England The pubHc's concern for the "health and productivity of forests in certain regions of the United States" resulted in federal legislation mandating "such surveys as are necessary to monitor long-term trends in the health and productivity of domestic forest ecosystems" (PubHc Law 100-521). This mandate was implemented in the six New England states in 1990 with the cooperative efforts of the U.S. Department of Agriculture Forest Service (USDA Forest Service), U.S. Environmental Protection Agency (USEPA), and the six New England state foresters. Subsequent legislation (Public Law 101-624) encouraged the USDA Forest Service to work in partnership with state foresters or equivalent state officials to "monitor forest health." 1 Forest Health Monitoring (FHM) is intended to be a long term efifort with a major emphasis to detect imexpected changes fix)m established baseline forest conditions. Specific objectives of FHM are to: 1) characterize forest conditions, 2) characterize the major potential forest stressors, 3) quantify changes in forest conditions, and 4) analyze the relationships between changes in forest conditions and potential forest stressors. Forest conditions will be described by the measurement and reporting of data fi*om several "health" indicators. Five indicator groups have been selected: growth, foliar S3rmptoms, soil chemistry, foUar chemistry, and landscape characterization. Individual measurements may support one or more indicators. Measurements will be made and indicators characterized on a periodic basis; annually for those that change frequently (for example, foliar symptoms) and on a 4 year or greater cycle for those that change less fi-equently (for example, soil chemistry). FHM is based on the annual remeasurement of an extensive network of permanent locations, selected to correspond to a systematic sampling grid developed by the USEPA for their Environmental Monitoring and Assessment Program. In New England, this sampling design )delds 263 s£imple locations on all lands, forest and nonforest. Each location consists of a cluster of foiu* plots. All trees, including seedlings and saphngs, are located, marked, and measured. On, or adjacent to the FHM location, openings in the forest are searched for indicator plant species known to be sensitive to ozone, sulfur dioxide, and hydrogen fluoride. At each location, data are collected on the geographic and topographic position and physiographic description of the location; tree species, diameter, crown position, crown condition, and damage; other vegetation; and foliar sjmiptoms on indicator plants. Data quahty standards are specified in the field data collection manual and explained during field crew training. These standards were monitored by the remeasiu*ement of a subset of locations and trees. 1990 Results Sample Distribution The 263 FHM locations in New England represent the forest resource as reported by the most recent forest surveys. The distribution of the forested plots does not differ significantly from that expected of previous forest surveys for land use, forest-type group, or stand-size class. 2 Number of New England Forest Heatth Monitoring Locations, by Major Forest-type Group and State or Region Southern Total Forest-type New h4ew New Group Maine Hampshire Vermont England^ England E. White Pine 18 7 4 5 34 Spruce-Fir 48 1 7 0 56 vjaK-mcKory o A \J 1 A 1 ft lO Northern hardwoods 37 19 10 5 71 Other groups 13 4 3 7 27 All groups 118 33 24 31 206 Nonforest 19 4 11 23 57 All plots 137 37 35 54 263 'Connecticut, Massachusetts, and Rhode Island. A total of 63 species, 14 conifers and 49 hardwoods, were talhed. This is less than the 76 species, 16 conifers and 60 hardwoods, tallied on the extensive forest survey plots. While the distribution of trees by species is not significantly different fi-om that expected, the numbers of balsam fir £uid white pine show large deviations fi-om expected values. Number of Trees on New England Forest Health Monitoring Plots,^ by Major Species and Tree Class Seedlings- Mature trees All op6CI6S saplings Live Dead Classes Balsam Fir 3,378 646 228 4,252 Red Spruce 665 711 63 1,439 E. White Pine 218 716 71 1,005 N. White-Cedar 309 358 32 699 E. Hemlock 293 426 11 730 Other conifers 223 148 30 401 All coiirfei*s 5,086 3,005 435 8 526 1,031 49 Sugar Maple 1,543 487 29 2,059 Yellow Birch 388 272 34 694 Paper Birch 664 338 39 1,041 American Beech 505 264 21 790 White Ash 565 175 8 748 N. Red Oak 264 188 3 455 Other hardwood 2,650 721 117 3,488 All hardwood 8,197 3,476 300 11,973 All species 13,283 6,481 735 20,499 'Data from 204 forested FHM plots; major species determined by those with greater than 170 sample trees. The less-than-expected number of balsam fir trees is probably a result of mortality caiised by eastern spruce budworm and increased cutting in response to budworm infestation. White pine was sampled at greater-than-expected levels in both the white pine and northern hardwoods forest-t)rpe groups and at less than expected levels in spruce-fir and oak-hickory forest-t3rpe groups. While there is no full explanation for these results, gypsy moth defoliation of white pine and accelerated mortality of the species since the last extensive forest surveys must be considered as one possible cause. The distribution of standing-dead trees by species is comparable between FHM and that expected from previous forest surveys. The distribution of trees by diameter class in the FHM sample differs significantly irom that expected of earlier forest surveys for both conifer and hardwood species. The difference is found in an "undersample" of conifers 3.0 to 8.9 inches in diameter and an "oversample" of hardwood saplings. 4 Tree Crown Ratings Each sampled tree was rated for three (hardwood) or four (conifer) crown characteristics: crown dieback, foliage transparency and discoloration, and needle retention. The ratings are reported only for upper-canopy trees (trees with crowns directly exposed to the atmosphere) though the data were collected for all-live trees. Across all forested plots, upper-canopy trees account for 69 percent of all sampled trees 5.0-inches or larger in diameter. Crown dieback Crown dieback is defined as branch mortality beginning at the tip of the branch and proceeding inward toward the trunk. This pattern of mortahty is an indicator of premature branch death. Dead branches in the lower crown are assumed to have died of suppression or natural senescence due to tree growth and are not included in this measurement. Ninety-six percent of all upper-canopy trees were tallied as having none-to-light crown dieback. Over all the plots, hardwood species gener£dly had greater crown dieback than conifers. More than 13 percent of the American beech sample was recorded with greater than 20-percent crown dieback. Without fiirther diagnosis, the cause of these symptoms cannot be specified, but the occurrence of the beech bark disease complex is a possible reason. The symptoms are compatible with this disease and the complex is well established in New England. Distribution of Open Grown, Dominant, and Codominant Trees on FHM Plots,^ by Percent Crown Dieback Class for Major Species Percent Crown Dieback Class None Light Moderate Severe Species (0-5%) (6-20%) (21-50%) (51+%) Percent of sampled trees Balsam Fir 91.4 7.2 1.1 0.3 Red Spruce 92.7 6.0 1.1 0.2 E. White Pine 92.4 6.6 0.8 0.2 N. White-Cedar 82.8 12.1 4.0 1.0 E. Hemlock 93.0 3.5 2.9 0.7 Red Maple 67.2 26.5 4.4 1.9 Sugar Maple 87.0 10.1 2.4 0.5 Yellow Birch 77.9 18.8 1.4 1.9 Paper Birch 68.6 27.0 3.1 1.4 American Beech 54.7 32.1 7.5 5.7 White Ash 71.3 25.0 1.5 2.2 N. Red Oak 50.0 49.4 0.0 0.6 *Data from 204 forested FHM plots 5 Foliage transparency Foliage transparency is defined as the amount of skylight visible through the foliated portion of a tree crown and accounts for foliage reductions due to insect damage, pathogens, or environmental stress. The degree of fohage transparency differs by species and depends on branching and leafing patterns. FoHage transparency serves as an estimator of defohation. Almost 96 percent of all exposed tree crowns were recorded with "normal" foUage transparency levels. Of the major forest species, severe foHage transparency symptoms (greater than 1 percent of the sample trees) were reported only for yellow birch, American beech, and northern red oak. Distribution of Open Grown, Dominant, and Codominant Trees on FHIVI Plots,^ by Percent Foliage Transparency Class for Major Species Foliage Transparency Class Normal Moderate Severe Species (0-30%) (31-50%) (51+%) (Percent of sampled trees) Balsam Fir 99.7 0.3 0.0 Red Spruce 99.8 0.2 0.0 E. White Pine 95.5 4.5 0.0 N. White-Cedar 91.9 7.6 0.5 E. Hemlock 97.9 2.1 0.0 Red Maple 95.6 3.5 0.9 Sugar Maple 98.9 0.8 0.3 Yellow Birch 96.2 1.9 1.9 Paper Birch 92.8 6.5 0.7 American Beech 86.8 6.9 6.3 White Ash 94.9 5.1 0.0 N. Red Oak 90.4 4.8 4.8 'Data from 204 forested FHM plots At this time there is no record to determine "normal" levels of foliage transparency for any species other than sugar maple. This siuvey will develop the data to estabhsh species-specific foHage transparency standards fi*om which to identify abnormal conditions. Presently, we can examine those tree records with high levels of foHage transparency (that is, thin crowns) for other indications of health problems (for example, other crown ratings, other signs and symptoms). 6 Foliage discoloration Foliage is considered discolored when the overall appearance is noticeably yellow, red, or brown. More than 50 percent of a leaf or needle must be discolored for discoloration to be tallied. The occurrence of trace amounts of discoloration is expected for any tree. Results from the 1990 field season provide no indication of health concerns expressed as early or abnormal discoloration. Needle retention Needle retention is defined as the number of years needles are retained by a conifer and indicates tree vigor. Needle retention is measured as the year of oldest needle-year class with more than 25 percent of the needles present. The longer the tree retains needles, the more vigorous its growth is expected. The results of needle retention measurements provide no indication of forest health concerns. Signs and Symptoms Signs and symptoms, indicative of previous injury, disease, or insects are recorded to provide an explanation of adverse growth effects or mortedity. The occurrence of a sign or symptom was recorded only when significant and when likely to result in the eventual dechne and death of the tree. A hst of common signs and sjonptoms had been provided and their occurrence w£is recorded when observed. Results from 1990 suggest no unexplainable forest health concerns. Indicator Plants Exposure to ozone, siilfur dioxide, and hydrogen fluoride, atmospheric gas pollutants, can cause recognizable foHar symptoms on certain plant species. These plants can serve as "bioindicators" of the pollutants. At, and adjacent to, each FHM plot, forest openings were searched for the presence of bioindicator plant species. Fohar S3rmptoms were recorded when observed. The presence of one or more indicator plant species, for one or more of the air pollutants, was recorded on 192 locations. Ozone S)miptoms were recorded on 18 locations, sulfur dioxide symptoms on 6 locations, and no hydrogen fluoride symptoms were observed. 7 Status of Major Forest Insects and Pathogens in New England in 1990 This summary reviews the major forest insect and pathogen problems and declines of 1990 in the New England states. The information was compiled firom state pest condition reports and surveys of the USDA Forest Service, Northeastern Area State & Private Forestry, Forest Health Protection, Durham Field Office. The major hardwood pests are defoUators. The New England oak — and at times white pine and hemlock — resource is still affected by extensive gypsy moth defoliation. In 1990, over 700,000 acres of defoliation were reported in the New England. DefoUation increased over the previous year's level, partioilarly in Maine, Vermont, New Hampshire, Massachusetts, and Connecticut. In many areas significant larval mortality occurred due to fungal infection; however, populations remain high or continue to expand in these states. Very low populations and no significant defoUation have been reported from Rhode Island in the last 2 years. Other hardwood defoHators such as the eastern tent caterpillar, forest tent caterpillar, and the oak leaf tier were at low levels ia most of the region. The incidence of pear thrips also was at a lower level than in recent years in most areas, however the insect caused increased damage in Vermont. Populations of the saddled prominent increased in Vermont and Massachusetts and caused defoliation in scattered locations. The major conifer pests include defoHators and stem and twig insects. Spruce budworm populations continue at very low levels in northern New England. The hemlock looper infestation in Maine is expanding, and the insect caused locahzed defoliation in Vermont. Damage from the hemlock woolly adelgid and red pine adelgid was noted in Connecticut and Rhode Island. These insects are expanding into Massachusetts and the hemlock woolly adelgid was foimd at one site in Vermont. The spruce beetle is causing mortality of larger spruce in northern Maine, and the area of infestation is increasing in size and intensity. This insect also is causing spruce mortality at other sites in northern New England. The balsam wooUy adelgid is causing damage to balsam fir crowns at scattered sites in northern New England. One of the more significant diseases in the region is beech bark disease. Damage fix)m the disease can be foimd throughout the region, but the amount of tree crown dieback and mortality varies. Cytospora canker on spruce and diplodia tip blight on pine has caused damage in several locahzed areas. Eiux)pean larch canker and scleroderris canker are stiU under quarantine in several states, however the incidence of these diseases is currently static. Several fohar diseases were reported this year. The most significant was Euithracnose, which caused damage on maple and other hardwoods in Vermont, Massachusetts, and Rhode Island. Dutch ehn disease is 8 common throughout the region, as a new, more virulent strain is spreading. Reports of localized drought effects and winter injury on conifers were reported in some of the states. In Maine a disease known as Stillwell's syndrome, associated with Armillaria root disease, continues to cause low levels of mortahty in balsam fir stands over an extensive area previously defoliated by the spruce budworm. Several diebacks on various species were reported. Ash dieback, commonly associated with ash yellows, caused mortality in Maine, Vermont, and Massachusetts. Larch mortahty, usually in association with the eastern larch beetle is occurring in Vermont and Maine. Birch dieback is reported fi*om Vermont and especially Maine, where several areas in the western and eastern parts of the state are affected. Dieback of maple is reported throughout the region, but in most cases less than 10 percent of the crown is affected and losses are insignificant. Spruce dieback continues to be reported, with the problem most noticeable at the higher elevations. The objectives of the 1990 FHM field season were the establishment of the permanent plot network and the collection of 1"* year crown rating and growth data. The FHM plot sample corresponds very closely to New England forest resource characteristics as reported by previous forest surveys. The distribution of locations and tree species are not significantly different firom expectations. Such deviations between samples as were foimd can be explained from known changes since the last extensive siuvey in the New England forest. The summary of crown ratings data from open grown, dominant, and codominant trees indicates no pattern of major decHne in any species. For many species, these data represent the first such measurement and an exact interpretation is difficult. The full value of the data, as well as diameter measurements, will be realized with plot remeasurements in succeeding years. This year's data will estabhsh the baseHne against which to identify changes in subsequent years.