| |
|||||
| |
|
|
|
||
| |
|
|
|
||
| |
|||||
|
Note: All links to Figures, Tables, and References in this section open
in a new window. Simply view, toggle back and forth if you wish, and close
the new window when you are finished viewing. |
|||
|
|||
|
| Figure 1. 1997 satellite image of forest land in Vermont |
An image taken by satellite instruments shows the state heavily forested (Figure 1). The heaviest concentrations of forest are found along the lengths of the various ranges of mountains and ridges running north and south. This view is borne out by the recent forest inventory of the state which shows it to be 78 percent forested, an increase of 1.4 percent since 19831. A similar image from 1948, if one were available, would show noticeably less forest cover across the state. The range and ridge concentrations would be distinguishable but the areas in between would show much less forest cover. The 1948 forest inventory showed that the state was 63 percent forested at the time1. In the 50 years since, the forest has increased in area by 25 percent.
During this 50-year period, as forest area was increasing, forest harvest was increasing as well. In 1948 total forest harvest was 723,100 cords; in 1997 it was 1,777,184 cords. During that time the harvest reached a low of 378,200 cords in 19712.
The inventory figures come from a periodic statewide survey of the forest conducted by the USFS, with the results supplied to the state. The harvest figures come from the annual harvest report published by the department since 1945. This report is based on data obtained from a canvass of the forest product buying businesses in the region. These businesses voluntarily report their purchases of Vermont forest products (logs, pulpwood, whole tree chips) for the calendar year.
In very basic terms, the forest has come to cover more of the landscape in Vermont over the 50 years since the first inventory was conducted. This is a remarkable recovery of the forest from 150 years ago, when it was widely accepted that forest cover was less than 25 percent. Since then, Vermont supplied wood products to two world wars and the post World War II building boom. The state has been home to a growing number of private forest landowners as well as a vibrant forest products economy. Although forest health varies from year to year and species to species, within these fluctuations, however, tree health is improving as well. Overall, the forests of Vermont are in good shape.
The forested area of Vermont has increased during each inter-inventory period, beginning with 1948 through 1966. Forest land as discussed here refers to land that is at least 10 percent stocked with trees of any size, or that formerly had such tree cover and is not currently developed for non-forest use1.
The two periods, 1948-66 and 1966-73, showed increases of 16 percent (592,300 acres) and 4 percent (171,700 acres), respectively. The periods 1973-83 and 1983-97 showed increases of 1.1 percent (50,700 acres) and 1.4 percent (63,900 acres), respectively. The increase since 1948 follow a previous half-century of forested area expansion from an estimated low of about 25 percent of the state. This trend follows the general trend of forests throughout the eastern U.S. over the same time period. In this half century forest cover has gone from 63 percent of the state to 78 percent1.
The trend described for forested area in Vermont over the past 50 years is clearly one of approaching a limit. While there is an absolute limit set by the land area of the state, it should be expected that other limits intercede to keep forested area less than total state land area. Agricultural land and urban or suburban style development represent the most significant limits to further expansion of forested area. What is clear from the trend is that Vermont is close to what could be considered as fully forested.
Comparing FIA data from previous inventories provides much more information than percent change in forest area. Since 1983, the forest has grown older and larger, occupies more land with more trees, and shows signs of continuing maturation (Figures 2, 3, 4, and 5). This is substantiated when data from 1997 is compared to data from 1948, the first year a periodic forest inventory of Vermont was conducted by the USFS. It should be noted that the data describe a statewide situation and therefore are a composite of varied conditions. While the data can be reported on the basis of the northern or southern half of the state and for each county, the reliability of these numbers is poor since conditions in a particular location or area may vary considerably from statewide or county-wide trends.
Vermont does not rely solely on the periodic statewide forest inventory for assessing the state of the forest. An annual harvest report is published, and forest health conditions are assessed periodically as well. The inventory is useful primarily to the degree that it can be integrated with the other data sets which the state collects.
Inventory details tell a slightly different story of conditions than do the overall measures. As with the discussion thus far, there are two benchmarks which are useful: change since the last inventory in 1983 and change since the first one in 1948. The longer-term change offers a unique opportunity to look at comparative forest conditions over 50 years. Since 1983 growing-stock volume has increased 38.8 percent. Growing-stock volume is the estimated cubic volume in trees which are at least 5 inches in diameter at 4.5 feet above the ground1. Growing-stock annual growth was estimated at 167 million cubic feet per year in 1997 (Table 1). This volume represents an annual growth rate of 1.93 percent in inventory per year. The comparable figures in 1983 were 182 million cubic feet and 2.90 percent per year, respectively. In 1948 the growth was 128 million cubic feet and the inventory was growing at a rate of 3.37 percent per year.
Growth and removals are included in Table 1. Net growth is the change, resulting from natural causes, in growing-stock volume during the period between surveys, divided by the number of growing seasons. Components of net growth are ingrowth plus accretion, minus mortality, minus cull increment1. Accretion is the estimated net growth on growing-stock trees that were measured during the previous inventory, divided by the number of growing seasons between surveys. The average annual removals are the volume of wood harvested on average for each year between inventories. This figure is not necessarily the same as the harvest for the year of the inventory. Average annual removals have been 93,554,000 cubic feet per year from 1983 through 1997 but the actual harvest in 1997 was 94,176,000 cubic feet2. While the growth-to-removals ratio is expressed as 2.02 to 1 using the average annual removal rate for 198397, the actual 1997 harvest yields a growth-to-removals ratio of 1.78 to 1.
Growth-to-removals ratio shows to what extent sustained yield exists in the forest. A 1:1 ratio indicates that harvest volume is equal to the growth in the forest. Sustained yield requires that harvest not exceed growth. Said another way, growth can be considered interest generated from the inventory, which is the principal. The goal of sustained yield is: never consume the inventory (principal). In 1997, 72,911,000 cubic feet of annual growth remained in the inventory after a harvest of 94,176,000 cubic feet.
The decline in the growth-to-removals ratio since 1973 and the decline in the growth rate since 1983 can be attributed in part to the increase in the number of trees (Figure 3) and the increase in the average tree diameter (Figure 4). The combination of more crowding and larger trees can yield a lower growth rate. The increase in harvest during the period 1973-97 also contributes to the decline in the growth-to-removals ratio.
Since 1966 removals (harvest) have increased nearly twofold (Table 1). It is expected that harvest will continue to increase as demand for wood continues to increase. The combination of increasing harvest and the decline in growth rate since 1983 makes it likely that the growth to removals will continue to shrink. The department will continue to monitor these trends and report on the findings.
Table 2 provides a more detailed look at the various categories that make up growth. In this table, removals are subtracted from net (average annual) growth to obtain net (average annual) change, terms used by the USFS. Figure 6 gives the graphic representation of this data.
Drawn from this data is the fact that removals from growth are from two sources‹mortality and harvest. Mortality has been increasing over the 50-year span. This increase is largely a function of the increase in the total number of trees and the general trend of increasing maturity of the forest (see Figures 3 and 4). Overall, there has been no easily described linear pattern or trend for growth volumes. The apparent spike in 1983 values could have been influenced by sampling methods. The number of plots from which growth data were recorded was about half the number used in inventories before and after 1983. (This difference in sampling method would not affect measures other than growth.)
If a number of variables are examined, it may be possible to speculate broadly about which direction the inventory figures might go in, assuming a variety of conditions. Given a continued maturation of the forest, it should be expected that growth rate will decline. Given a continuation of increases in removal volumes, the growth-to-removals ratio can be expected to move closer to 1:1 levels. Given no catastrophic and widespread weather events, or pest or disease epidemics, mortality rate should continue to track along its present trend. The net result for the future, as presented for the past and the present, is very difficult to assess. In order to better assess the future using the data that is available, Vermont, New York, New Hampshire, and Maine will commission and participate in a region-wide forest growth modeling project in partnership with USDA Forest Service. The outcomes of this project will include a projection of timber supply over the next 50 years, as well as projections of a number of forest condition variables. The results of this project will be used to better understand present inventory results and to begin to develop understanding of what effects current trends and practices could have on the forest of the future.
The periodic forest inventory provides some data on forest structure and composition. This information is limited, however, to overstory populations and does not offer any insight into forest floor composition or natural communities. Tree or forest age are not well measured by this inventory and cannot be provided for this assessment.
The Forest Resources Advisory Council (FRAC) considered measures of forest structure as a means of monitoring forest sustainability. The measure suggested focused on three categories of size: seedlings and saplings, pole-sized trees, and sawtimber-sized trees. Pole-sized trees are from 5 inches in diameter at 4.5 feet from the ground to 8.9 inches for softwoods and 10.9 inches for hardwoods. Sawtimber-sized trees are from 9 inches in diameter and up for softwoods and 11 inches and up for hardwoods.
The FRAC deliberations centered on the proportions of these size classes. Foresters and ecologists suggested that a healthy proportion of number of trees would be 50 percent in saplings, 30 percent in pole-sized trees, and 20 percent in sawtimber-sized trees but inventory figures fall short of this mark. In 1983 the mix was 67.5 percent for saplings, 24.3 percent for pole-sized trees, and 8.2 percent for sawtimber1. In 1997 the mix was 73.2 percent for saplings, 19 percent for pole-sized trees, and 7.8 percent for sawtimber. The distributions for 1966, 1973, 1983, and 1997 (Figure 7) show no trend in structure change over the four inventories. No data exist on the size classes of harvested trees that would help explain the back-and-forth shift in this distribution since 1966 (1948 data is not available).
The FRAC deliberations were intended to lead to an understanding of what mix of sizes would be best for a continued flow of preferred forest products while maintaining forest structure integrity. To the extent that this way of looking at forest structure is meaningful, it appears clear that current inventory proportions favor the seedling/ sapling class at the expense of both pole-sized trees and sawtimber-sized trees. While this shows that there is a strong complement of young trees to perpetuate the forest, the consistently less than optimal proportion for sawtimber requires further investigation. The department will continue to monitor and report on this and other compositional attributes of the forest.
Forest composition can be viewed from the periodic inventory by way of the acres occupied by standard forest types (Figure 8). Composition in general can be looked at two ways: commercial and biological. For commercial interests, there are some species of trees which are not desirable because the market places little value on them. From a biological viewpoint, those commercially less valuable species may be valuable for wildlife or maintaining a diverse mix of trees for biodiversity. A long-range commercial viewpoint can be oriented toward seeing all tree species as necessary in the forest since over the long term it is not possible to anticipate what the market demands may be. A diverse mix of trees can also be valuable in terms of reducing the impact of species- specific diseases or insects.
Figure 8 shows the acreage for each forest type for 1966-97; forest types used in 1948 do not match with those used in subsequent inventories. The data show a clear trend of type shifts. The maple/beech/birch forest type has been increasing in acres substantially. All other types have declined in area or shown little change. Figure 9 shows the number of trees by species for 1973, 1983, and 1997. No data were available for 1966.
Since 1973, sugar maple has approached 20 percent of total growing-stock trees in inventory and then receded slightly. During the same period, red maple's share of inventory has gone from less than 10 percent to nearly 13 percent. Likewise, beech (4 percent to 6 percent) and oak (1.5 percent to 2.5 percent) have enjoyed increasing shares of inventory, though their gains were modest. The birches and aspen have lost their shares of inventory over the period while ash and the collective other hardwoods have remained at about the same level. Other hardwoods include cherry, basswood, hickory, and elm.
For softwoods, spruce has lost its share of inventory, dropping from 12 percent to 8 percent from 1973 through 1997. Balsam fir started and ended the period with about 10 percent of the total number of growing-stock trees, dropping to 8 percent in the intervening inventory. White pine and other softwoods have decreased their shares slightly but steadily over the period. Only hemlock showed a steady increase in its share of inventory by number of trees, having gone from 7 percent to 10 percent.
Sugar maple, red maple, balsam fir, and hemlock each make up 10 percent or more of the total number of growing-stock trees statewide; all other species represent less than 10 percent each. Of those species at or over 10 percent, hemlock and red maple have been clearly increasing their shares of inventory. As a result of past inventories, foresters have learned to watch the red maple component of the inventory as a trend of concern. Red maple does not enjoy strong commercial demand or commensurate pricing. Hemlock appears to be developing within the inventory along a trend that may require attention as it carries a lower commercial interest as well. It is also worth noting that beech may deserve monitoring, though the trend in its proportions is one of only modest gains.
The overall pattern of forest composition has been one of fewer species making up more of the inventory in terms of number of trees since 1973. The department will continue to monitor these trends and others that may emerge or develop over the next 10 years.
The changing type and species composition of the forest, the relatively low proportion of sawlog-sized trees in the population, the shrinking growth-to-removals ratio, and the declining growth rate all raise issues about sustainability and diversity. A forest more concentrated in seedling and sapling-sized individuals with no long-term trend in increase of sawlog-sized tree numbers and with greater concentration in maple species indicates a move away from diversity. When the trends for the growth rate and the growth-to-removals ratio are added, there is no reason to expect that these trends will change during the course of this plan. The department will continue to promote uses for a wider array of species and grades to monitor and report on these trends, and to promote and encourage forest management to private landowners. Cooperating with the USFS in collecting and analyzing data on forest composition and health will continue.
The forest inventory information presented in the preceding sections offers some insight into the spatial status of the forest. While there is some information reported through the inventory which describes commercial quality of the timber, little is offered concerning the health and vigor of trees. This situation is one, as with harvest, where Vermont must rely on other information sources for assessing conditions.
The forest inventory describes conditions at the point in time of measurement and provides the opportunity to compare these measures with past data. Indicators of forest structure and composition can yield indications about the future of the forest. Other strong indicators of future forest conditions, particularly over for a longer time frame, are provided by measures of forest health.
The combination of forest health indicators, forest inventory data, and forest harvest information presents a powerful complex of data for monitoring forest conditions and anticipating change. During the 1997 FIA, one-third of the plots coincided with ground plots established through the National Forest Health Monitoring (NFHM) Program5. This national program began in 1990 and is administered by the USFS, while the field data is collected by state agencies. The goal of this program is to monitor and report on the status, changes, and long-term trends in the health of our nation's forests. The department will cooperate with the USFS in future assessments to develop methods for better integrating forest health and forest inventory data.
Based on combined FIA and NFHM data collected in Vermont in 1997, 97 percent of the overstory trees had low dieback (Figure 10). Dieback is measured as a percent of branch tips which are found dead. The amount of dieback differs among tree species and the normal processes of tree growth. The crown density indicator showed that only half of overstory trees were considered in good condition8. This is comparable to regional results from the NFHM program. Trends in dieback and crown density over time may be important in determining long-term forest health.
Conifer species were in generally good condition. White pine and hemlock were the only species with an average crown density less than 50 percent. White pine also had a relatively higher foliar transparency. This may be normal for this species, which tends to have fewer branches and less needles than other species. As Figure 11 shows, dieback averages were very low, with all species averaging less than 5 percent8.
Hardwood species health indicators were somewhat less favorable than in conifers (Figure 12). Red maple, beech, black cherry, and red oak all had crown density averages below 50 percent and average foliage transparency greater than 15 percent. While this may indicate less than ideal health condition, these measurements may also show differences in branch architecture between species. Black cherry was the only species having an average dieback rating greater than 5 percent. These results compare favorably to other surveys conducted to assess forest health. The forest resource as a whole appears to be in a mostly healthy condition.
No single measurement can summarize forest health. Instead, a series of indicators serve as a reflection of existing conditions. Repeated monitoring of forest health over time helps identify trends and changes in forest conditions. Information on forest health is obtained through the use of permanent inventory plots, ground surveys, aerial surveys, and specific research studies. Done in conjunction with the USFS and duplicated by neighboring states, these combined efforts emphasize monitoring, assessment, and reporting.
The department maintains a number of permanent monitoring plots used to determine changes in tree health over time. The statewide Hardwood Tree Health Survey is the longest running survey, first conducted in 1985-86 and repeated in 1990-91 and again in 1995-964. Using both aerial photos and ground surveys, the latest survey shows that, overall, Vermont's hardwood forests are in good condition, with continued improvements since 1985. More than 2.5 million acres of hardwood forests were estimated statewide by interpretation of 1985 photos. Over 13,000 acres of this total were estimated to have moderate to heavy mortality (more than 10 percent of upper canopy trees dead), but that figure dropped to 4,000 acres in 1990 and 1,000 acres in 1995. Tree health based on ground evaluations also improved during the 10 years. Of trees in upper canopy positions, 78 percent were healthy (0-10 percent crown dieback) in 1986, increasing to 86 percent in 1991 and 89 percent in 1996.
The North American Maple Project focuses on the health of sugar maples. This survey also shows an improvement in the health of sugar maples in Vermont since the survey began in 19883. In 1994, 92 percent of the sugar maples in Vermont sugarbushes were reported to be in healthy condition based on crown dieback. This compares with 89 percent healthy for sugar maples in hardwood stands in 1996 (versus 81 percent in 1991) based on the Vermont Hardwood Tree Health Survey.
As previously mentioned, the department also participates in the National Forest Health Monitoring Program (NFHM). Individual tree data is collected from permanent plots on crown dieback, foliage transparency, crown density, damage to trees, and ozone injury. Some of these plots also served as FIA plots in 1997 and will be the basis for future FIA data collection. One of the NFHM measurements of tree health is crown dieback. A summary of data for all of the plots in New England and New York show little change since 1990, averaging 97 percent of trees healthy for all tree species in 1996 (Figure 13).
Damage caused by diseases, insects, weather extremes, and other agents can have both a positive and negative impact on ecosystem health. A certain amount of damage is to be expected and is even desirable for the forest ecosystem in general. However, sometimes the damage can be extreme, and it causes reduction in tree growth and increases the likelihood of mortality. The department collects data on tree damage in a variety of ways. Annual aerial surveys are conducted to survey damage by forest insects and diseases; the results have been published in annual reports since 1974 6. Acres defoliated by forest insects peaked in 1980-82 and have remained very low since 1988 (Figure 14).
Damage with the potential to kill trees is measured through NFHM. The majority of the trees in the sample plots have no visible signs of damage that threaten their long-term growth and survival. Of the 20 percent of trees with some degree of damage, decay is the most commonly observed type. Hardwood trees tend to have more damage than conifer trees.
Although statewide surveys have shown that trees are generally in good condition, some upper elevation sites monitored by the Vermont Forest Ecosystem Monitoring Cooperative contain a greater proportion of unhealthy trees. In 1996, yellow birch at 2,200 feet elevation and balsam fir at 3,800 feet elevation on Mt. Mansfield showed trends toward increasing percentage in dieback. The 2,200 feet elevation plots in the Lye Brook Wilderness Area, however, had low dieback in 1996 (5.1 percent) and improved in crown density and foliage transparency compared to 1995. Black cherry at 1,400 feet elevation at Lye Brook had higher average dieback (12.5 percent) than other species7.
Despite the increased interest in forest health and its obvious importance, forest health is not easy to define. It is a concept that involves not only scientific data but also a consideration of uses of the forest, perceptions of various forest interest groups, and personal value judgements. In general, trees are in good condition in Vermont. On average, trees of most species fared well in terms of a number of variables that measure the condition of tree health. The department will continue to participate in national forest health monitoring efforts and provide timely information to forest owners and managers.
Another measure of forest ecosystem health can be explored by looking at the percent of rivers, streams, and lakes with acceptable water quality and biological indices for aquatic insect host communities. Every 2 years the State of Vermont is required by the Clean Water Act to submit a list to the U.S. Environmental Protection Agency of waters for which required technology-based pollution controls are not stringent enough to meet Vermont Water Quality Standards. In their 1998 report, the Water Quality Division of the Department of Environmental Conservation documents that 79 percent of the state's assessed river/stream miles are fully acceptable or supporting the requirements of the Vermont Water Quality Standards9.
Approximately 61 percent of Vermont's assessed lake acreage (not including Lake Champlain) is fully acceptable or supporting. Lake Champlain is impaired, with no acres supporting the standards due to a variety of causes, for example aesthetic quality and mercury in fish tissue. Atmospheric deposition has had a significant impact on pH, affecting the aquatic ecosystem of lakes and ponds in the Northeast and certain areas in Vermont. Levels of pH below 5 are considered to be detrimental to water chemistry and aquatic life. Approximately 30 miles of Vermont's 5,260 miles of assessed rivers and streams, and 4,100 acres of Vermont's 53,400 acres of assessed lakes are impacted by pH9. Control of pH levels, which is impacted by activities outside the borders of Vermont, is being pursued by various means, but improvements are expected to occur slowly.
Attempting to establish trends in water quality is not easy, due to differing methodologies of stream assessment. In addition, public awareness efforts and the formation of local watershed groups have increased detection. However, since the completion of all Vermont's planned wastewater treatment facilities, the water quality of 58 rivers and streams and 3 lakes has improved. Yet, this point-source pollution is only 10 percent of the water quality problem. Non point-sources pollution, that which cannot be attributed to a single source, accounts for 90 percent of the water quality issues in Vermont.
Forest management activities have the potential to cause non point-source pollution. In 1987, Vermont's Water Quality Standards were revised to include Acceptable Management Practices (AMPs) which establish minimum standards for erosion control practices to reduce sedimentation and run-off from logging operations. In a 1990 Memorandum of Understanding between the Department of Environmental Conservation and FPR, a process was established to work with the Vermont Forest Products Association (VFPA) to assist loggers or landowners when a discharge is reported. According to the agreement, a five-member technical advisory team conducts site visits to assist logging contractors and landowners in meeting the AMPs. Enforcement proceedings are carried out only when there is substantial failure to comply with the AMP's already has or is likely to result in substantial environmental degradation, when efforts to obtain voluntary compliance have been unsuccessful, or when there is a history of noncompliance with the AMP's coupled with discharges to state waters.
The number of water quality complaints received and investigated from 1989 through 1998 shows no obvious upward or downward trend. Complaints have ranged from a low of 23 in 1992 to a high of 66 in 1998. Many variables need to be considered for a comprehensive evaluation. They include, but may not be limited to, soil and weather conditions, level of timber harvesting (number of operations), landowner and logger attitudes, and effectiveness of educational and enforcement efforts. Annual summary reports of technical advisory team activities from 1989 through 1998 are depicted in Figure 15. Most of the efforts expended by the teams (56 percent) deal directly with real water quality problems on timber harvesting operations. Voluntary compliance is usually achieved without resorting to enforcement action, and discharges to State waters are brought under control in a timely fashion. Another 21 percent of all cases investigated reveal that these complaints originated from other concerns not related to water quality, such as aesthetic impacts of timber harvesting, encroachment or potential impact on a drinking water source, and general erosion concerns. Members of the teams also provide on-site technical AMP assistance to loggers upon request. This accounts for another 21 percent of all cases. Most assists deal directly with stream crossings. From 1989 through 1998 only 2 percent of all cases were settled with an enforcement action taking place. Enforcement consisted of levying monetary penalties.
The program continues to keep water quality violations from logging activity to a reasonable and manageable level. It continues to have support from the VFPA, whose members serve without compensation on the advisory team. This program should continue in its present format.
The wetlands of Vermont are a significant resource providing food, habitat for fish and wildlife, and recreational opportunities. They also play an important role in maintaining water supply and quality. The U.S. Fish and Wildlife Service, in conducting its national wetlands inventory, classified a total of 220,00 acres, or about 4 percent of the state's land area, as wetlands11. Over half of the wetlands are forested, with nearly equal amounts distributed between broad-leaved deciduous and needle-leaved evergreen forest types. Scrub-shrub wetlands account for less than one-third of the state's wetlands. Figures are available for the acreage of wetlands owned by the Department of Fish and Wildlife and federal agencies; however, acreage owned by the Department of Forests, Parks and Recreation is unknown. It is estimated that over 90 percent of all wetlands are located on private land.
Over the past 10 years, an estimated 10-30 acres of known wetlands were lost per year. This compares favorably with acreage losses from around the country. Vermont seems to have good regulatory control on projects in and near wetlands.
Ecomapping is part of a worldwide and national system of dividing the landscape into fairly homogenous biological units based on where similar types of vegetation grow. In Vermont, a cooperative effort between the Agency of Natural Resources, the USFS, the USDA Natural Resources Conservation Service (formerly the Soil Conservation Service), and the University of Vermont came up with a mapping system which was generated through ordination and classification analysis of FIA data as well as climate and soil data for the state. This approach allows for more definition in the land classification system developed by the USFS, but has been coordinated with neighboring states so that it would fit into the regional mapping system.
The state is divided into eight Biophysical Regions: Champlain Valley, Northeastern Highlands, Northern Green Mountains, Northern Vermont Piedmont, Southern Green Mountains, Southern Vermont Piedmont, Taconic Mountains, and the Vermont Valley (Figure 16). Detailed descriptions of these regions are still being developed, primarily under the jurisdiction of the Vermont Nature Conservancy and the Non-Native and Natural Heritage Program of the Department of Fish and Wildlife. In addition to the biophysical regions, another mapping unit was introduced based on elevational zones or Land Type Associations (LTA). Land under jurisdiction of the Agency of Natural Resources has shifted to the use of biophysical regions and natural community typing in long-range management planning.
A myriad of plant and animal species are dependent on Vermont forests for their habitat, but data is not collected on the majority of these species. The Department of Fish and Wildlife, Non-Game and Natural Heritage Program does collect information on rare, threatened, and endangered species. These species include mountain lion, lynx, marten, small-footed and Indiana bats, timber rattlesnake, and five-lined skink. Information is also collected on loons, falcons, osprey, and marshbirds, but only falcons are at all tied to forested habitat and then not all that closely. The Vermont Institute of Natural Science has been conducting forest bird monitoring and published recent results in a November 1997 report12. The Vermont Forest Bird Monitoring Program (FBMP) conducted a statistical analysis of bird census during an 8-year period at 17 study sites located in mature, forested habitats in Vermont. The results showed significant declines in breeding populations of black-capped chickadee, solitary vireo, Canada warbler, and several year-round residents, but showed significant increases in rose-breasted grosbeaks and neotropical migrants.
Forming any solid conclusions from trends in fluctuating bird populations is difficult; variations may be the result of short-term population shifts or the severity of winters. Numerous studies have documented declines in populations of neotropical migratory songbirds inhabiting highly fragmented landscapes. Continued monitoring of bird populations, through efforts such as FBMP, will help document the relationship of healthy populations of forest-dwelling songbirds with the health and productivity of forest ecosystems12.
The black bear population in Vermont is restricted to approximately 60 percent of the state, primarily along the Green Mountain spine and in the Northeast Kingdom. Historically, black bear occupied the entire state. Throughout the last century and a half, bears have been restricted to the lower quality habitat in the mountain regions as a result of increasing human development and habitat fragmentation in the valleys. Black bears need large forested blocks of sufficient size to meet the home range and food requirements of female bears and cubs. The existing range, although becoming increasingly more fragmented, supports the present bear population. The survival of the existing population depends on large tracts of remote, relatively undeveloped land. In Vermont, this includes the large blocks of forested habitat currently owned by private individuals or timber companies as well as publicly owned lands. A significant loss of habitat base would threaten the ability of Vermont to support the existing black bear population. The current black bear population estimate for 1998 is 3,000; it is increasing in the short term13. There is no data maintained on specific critical habitat for bear (beech stands, wetlands, etc). Local monitoring efforts have been used to identify these resources and should continue.
A commonly recited Vermont success story on wildlife re-introduction is the turkey. Expatriated in the state prior to the 1960s, Vermont's turkey population continues to expand, which has been the trend since 1994. An estimate of current population falls in the range of 23,000 to 25,000 birds, distributed throughout every county in the state. Harvest data shows an increase of 2,000 birds from 1978 to 1998.
White-tailed deer have been a highly prized game species in Vermont for over 100 years. Presently, about 100,000 residents and nonresidents participate in one of Vermont's four deer seasons. The latter half of the 20th century has seen the deer population go from boom to bust to boom again. However, large deer populations are not always desirable when considering sustainability of the species and all of the other native plants and animals of Vermont. The Fish and Wildlife Department's deer management plan calls for a deer population density not to exceed 20 deer per square mile statewide, or roughly 165,000 animals. Regulated hunting of bucks and does is the primary method of achieving this goal. An annual harvest of 18,000 to 25,000 deer is estimated to be an optimum range for sustaining a healthy deer population and a healthy forest (Figure 17).
Moose continue to expand their range throughout Vermont. Reports of moose sightings or moose signs have been recorded in 231 towns, or 92 percent of all towns in Vermont. Non-hunting moose mortality, primarily from motor vehicles collisions, is also on the rise. Based upon hunting and non-hunting mortality surveys, the 1997 moose population was estimated at over 2,300 animals13. Annual net growth of the moose population statewide is estimated at around 10 percent. One hundred moose were legally harvested during the 1997 hunting season.
| |
|||||
| |
|
|
|
||
| |
|
|
|
||
| |
|||||
Forests, Parks & Recreation |
Agency of Natural Resources | Contact Us
For more information, use this e-mail address
This site maintained by ConEd
Site design by Ghostwriters Communications
