A Summary of forest and non-forest land by ecological sections in the Southern Appalachian Assessment area (fig 5).
Today, the Southern Appalachians testify to the great conservation efforts of the past century. The land is once again predominately forested. There are many economic opportunities to use natural resources. Once again, the ecosystems are among the most biologically diverse in the world. Populations of deer and turkeys are large and growing. The restoration of the Southern Appalachians is a great story, but a new generation of conservationists is concerned about new threats to the region's terrestrial natural resources.
The terrestrial assessment addressed two important ecosystem elements - plant and animal resources and forest health. Assessment topics included broad landscape habitat and land cover patterns, federally listed threatened and endangered (T&E) species, rare species and communities, popular game species, possible national forest old-growth forest, oak decline, exotic pests and diseases, disturbance, biological diversity, fragmentation, black bear habitat, genetic conservation programs, and neotropical migratory birds. This assessment of terrestrial plant and animal resources addressed four questions:
- Species with viability concern?
- Unique or underrepresented communities?
- Wildlife species that are hunted, viewed, or photographed?
- Species for which there is high management/public interest?
- Species having special or demanding habitat needs?
- Species considered true ecological indicators?
- Conserve populations of species with viability concern?
- Maintain the existing species and community diversity that will not result in the loss of viability of any plant or animal species (in the context of the entire Southern Appalachian region)?
- Provide sustainable levels of species populations at desired levels on national forests?
The forest health assessment also addressed four questions:
Broad Vegetation Classes
To help describe the structure of the SAA ecosystems, sixteen broad landcover classes were identified to characterize habitats across the SAA area. These broad landcover classes included: northern hardwood forests, mixed mesophytic hardwood forests, oak forests, bottomland hardwood forests, montane spruce-fir forests, white pine-hemlock forests, southern yellow pine forests, white pine-hemlock-hardwood forests, mixed pine-hardwood forests, grass-shrub habitats, barren land, agricultural cropland, agricultural pasture, wetlands, developed land, and water. Classes of old-growth forest types were identified for an analysis for possible old growth on National Forest System lands. The forest classes were further characterized according to successional classes to better describe forest landscape conditions. These successional classes have different plant and animal species associated with them. Forest early-successional stages (0 to 10 years old) provide for habitat for species such as bobwhite quail, ruffed grouse, Bachman's sparrow, and prairie warbler, while forest late-successional habitats (beginning at ages 60 to 90 depending on forest type) provide important habitat components such as large cavity trees, large snags, and denning trees for species such as pileated woodpecker, black bear, and gray squirrel.
Landcover Classes Total Acres % of Total SAA ----------------- ---------- ------ Forest Cover Types 26,172,425 70.0 ------------------------------------------------------------ Deciduous Types 17,621,894 47.1 Northern Hardwood 615,004 1.6 Mixed Mesophytic Hardwood 3,126,124 8.4 Oak Forests 13,427,883 35.9 Bottomland Hardwood 452,883 1.2 Evergreen Types 4,514,743 12.1 White Pine-Hemlock 665,925 1.8 Montane Spruce-Fir 90,101 0.2 Southern Yellow Pine 3,758,717 10.1 Mixed Types 4,035,743 10.8 White Pine-Hemock-Hardwood 830,565 2.2 Mixed Pine-Hardwood 3,205,223 8.6 Nonforest Cover Types 11,233,231 30.0 ------------------------------------------------------------ Grass/Shrub, Old Fields 1,528,350 4.1 Agricultural Cropland 1,271,222 3.4 Agricultural Pasture 6,522,433 17.4 Developed 1,169,798 3.1 Barren 112,529 0.3 Water 556,237 1.5 Wetlands 72,662 0.2 ------------------------------------------------------------ Totals 37,419,400 100.0
Figure 32
A Summary of forest and non-forest land by ecological sections
in the Southern Appalachian Assessment area (fig 5).
Since the mid-1970s, acreage of forest land has decreased by around 2 percent. Acreage of forest early-successional and late-successional classes has increased over the same time period, while sapling-pole classes decreased and mid-successional classes held steady. Seventy percent of the total forest area is in mid- to late-successional stages, with the remaining 30 percent in early- and sapling-pole successional stages (fig. 33). Acres of urban developed land have increased in size since around 1980, while all other nonforested lands have decreased in acres. Private lands contain the highest proportion of forest early-successional, sapling-pole, and mid-successional classes. National Forest System lands contain the highest proportion of forest late-successional classes (fig. 34). Trends for successional classes within ownerships do not exactly mirror the trends for the SAA area as a whole. For instance on national forests, early-successional classes have decreased and sapling-pole classes have increased since the mid-1970s. Around 1.1 million acres of possible old-growth forest were identified in an initial inventory of SAA national forests (fig. 35).
The SAA area contains an estimated 80 species of amphibians and reptiles, 175 species of terrestrial birds, 65 species of mammals, 2,250 species of vascular plants and possibly as many as 25,000 species of invertebrates (fig. 36). It was not possible for the assessment to address each of these species separately.
Figure 36
The Southern Appalachian region is one of the most botanically
diverse regions in the temperate zone. Heller's blazing star is
one of the 2,250 species of vascular plants in the SAA
area.
Figure 37
The assessment gave special emphasis to 472 species of plants
and animals.
Figure 38
Most of the special emphasis species have such limited
populations that there is concern about their viability.
A list of 51 federally listed threatened and endangered terrestrial species was developed for the SAA using information from the U.S. Fish and Wildlife Service, each state's Natural Heritage Program, and from scientific peer review. Habitat relationships were determined for all T&E species. It was found that around 65 percent of these species are associated with eight rare community groups. That percentage goes to 84 percent when streamside habitats are included.
The county distribution for the number of listed and proposed threatened and endangered species is shown in figure 39. An occurrence is a single record from the state Natural Heritage Program data. Each species occurrence record has information regarding the quality of the data and species status, as well as habitat data for the site. The Blue Ridge Mountain section contains the highest number of terrestrial species (31) and the highest number of occurrences (300). Most occurrences of federally listed species are on private lands, followed by national forests, national parks, and states' lands. Further analysis for species associated with particular habitats is available in the Terrestrial Report.
Figure 39
The Blue Ridge Mountain Ecological section contains the
highest number (31) of threatened, endangered and proposed
terrestrial species.
The county distribution for the number of species with viability concerns is shown in figure 40. The Blue Ridge Mountain section contains the highest number of terrestrial species and the highest number of occurrences. Most occurrences of the viability concern species are on private lands, followed by national forests, national parks, and state lands. Further analysis for species associated with particular habitats is available in the SAA Terrestrial Report.
Figure 40
Number of terrestrial species with viability concerns by
county.
In the past 25 years, deer and turkey populations have increased in the Southern Appalachians (figs. 41 and 42). The restoration of these species is due to the extensive restoration efforts, protection and conservative harvest strategies, as well as increased acorn production resulting from the increase in mid- to late-successional oak forests (fig. 43). Outlook for these species is for current population trends to level off within the next 15 years.
Figure 43
Restoration efforts, harvest strategies, and improved habitat
have benefited turkey populations.
Figure 44
A moderate expansion of black bear range is a result of
conservative efforts.
Figure 46
Approximately 21 million acres are potentially suitable for
black bears.
Figure 49
Bobwhite populations have declined due to losses of
agricultural lands.
Habitat suitability spatial analysis was conducted for selected species groups. These species groups lend themselves to broad, landscape-level analysis using remote sensing data. Seven habitat suitability models were developed and analyzed. The results for black bear are included within game species. The results are provided for (1) area-sensitive mid- to late-successional deciduous forest species, (2) general high-elevation forest species, (3) seeps, springs, and streamside species, (4) high-elevation bald early-successional species - early-successional grass-shrub species, (5) closed canopy deciduous forest species, and (6) high-elevation spruce-fir-northern hardwood forest species. It should be noted that these landscape-level models represent only gross habitat suitability based on general habitat requirements. Many species included have very specific, micro-habitat requirements not discernible in a broad scale analysis. Therefore, results of the suitability models should be viewed as providing a regional scale picture of habitat potential among ownerships and ecological units rather than an indication of site-specific presence or absence of a particular species or group.
This species group is made up of 16 birds, associated with mid- to late-successional deciduous forests, including neotropical migrant species, such as cerulean warbler, hooded warbler (fig. 50), and wood thrush. All the species included in this group are considered to be area-sensitive, requiring continuous forested tracts. Many also avoid forest edges during nesting and therefore are considered forest interior species.
Figure 50
Hooded warbler is one of 16 birds that require mid- to
late-successional deciduous forest.
Figure 51
About 8.2 million acres of mid- to late-successional forest
have the potential to support all 16 species identified as area
sensitive.
Based on past trends in land use, it is expected that over the next 15 years overall habitat acres in larger tract sizes and associated forest interior habitats will continue to decrease due to loss of forest land to other land uses such as agricultural pasture and development. These decreases may continue to be most evident in the sections currently with less than 70 percent of the area forested. These decreases should be seen primarily on other private lands.
This group includes seven species associated with higher elevation forests, including three area-sensitive birds, blackburnian warbler, black-throated blue warbler (fig. 52), and Canada warbler. This species group is primarily associated with mid- to late-successional montane spruce-fir, northern hardwood, white pine-hemlock-hardwood, and mixed mesophytic hardwood forests. There are approximately 355,000 acres of high-elevation forest in the assessment area, of which 149,000 acres (42 percent) are in tracts greater than 5,000 acres. These large tracts have potential to support all seven general high-elevation forest species. The majority of high-elevation forest is in the Blue Ridge Mountains. National park and national forest lands contain the large majority of these habitats.
Figure 52
The black-throated blue warbler prefers high elevation
forests.
This group includes 31 species associated with forested riparian areas as well as those found in springheads, seeps, and river gravel bars (fig. 53). Some species included in this habitat association are Acadian flycatcher, Junaluska salamander, harperella, and Ruth's golden aster. There are approximately 2.3 million acres of riparian habitat in the assessment area, 1.5 million acres (65 percent) of which is in forest cover. Due to limitations of the remote sensing data, habitat suitability modeling was attempted only for forested riparian habitat. Species associated with forested riparian habitat included a number of salamanders and fewer numbers of plants, birds, and mammals. A large majority of the forested riparian habitat is on private land. The future quality of these habitats is uncertain and may decline due to threats from hemlock woolly adelgid, an exotic insect.
Figure 53
Species such as the spotted salamander can be found in seeps,
springs, or streamside habitat.
These two groups include species associated with open conditions including early-successional forests (i.e., 10 species that include bobwhite quail, eastern cottontail (fig. 54), prairie warbler, and Bachman's sparrow) and, grassy and heath balds and old fields (i.e., 18 species that include Blue Ridge goldenrod (fig. 55), Roan Mountain bluet, and chestnut-sided warbler). There are approximately 1.5 million acres of early-successional habitat at lower elevations and 27,000 acres above 3,500 feet. The majority of this habitat is found on private lands (97 percent and 71 percent for low and high elevation). National forests provide 2 percent of the low elevation early-successional habitat, but 25 percent of the high-elevation early-successional habitat. The Southern Cumberland Plateau and Southern Ridge and Valley and Southern Appalachian Piedmont contain much of the low elevation grass-shrub habitat. Eighty-six percent of the high-elevation early-successional habitat is in the Blue Ridge Mountains.
Figure 54
The eastern cottontail is an early successional
species.
This group includes species associated with higher elevation mid- to late-successional spruce-fir and northern hardwood forests that includes the spruce-fir moss spider, purple turtlehead (fig. 56), Carolina and Virginia northern flying squirrel, and Cheat Mountain salamander. There are approximately 184,000 acres of high-elevation spruce-fir-northern hardwood forest in the assessment area. Almost 80 percent of this habitat is located on national park and national forest lands. The majority of the high-elevation spruce-fir-northern hardwood habitat is in the Blue Ridge Mountains. The outlook for this community and the 23 species associated with these high-elevation habitats is uncertain due to the negative effects caused by air pollution and exotic pests. A downward trend for these habitats is expected over the next 15 years.
Figure 56
The purple turtlehead is associated with high-elevation
spruce-fir and northern hardwood forests. Almost 80 percent of
the high-elevation spruce-fir and northern hardwood forests is
on national forests and parks.
The mid- and late-successional deciduous forests in the Southern Appalachians are an important habitat for 80 of the 472 species on the SAA special species list. Less than 50 percent of this habitat is in tract sizes greater than 5,000 acres, with most of these tracts occurring on national forests and national parks. Maintaining the larger tracts will support all species associated with mid- and late-successional forests. Late-successional deciduous forests provide special habitat features required by some species, such as large cavity trees, large standing snags, and den trees. Spatial arrangement of these features will enhance the habitat.
Maintaining federally listed and viability concern species associated with these habitats may require protecting species occurrence locations from road construction, preventing loss of forests to development, and providing mitigating measures for some silviculture practices.
Early-successional habitats (0 to 10-year-old forest communities and abandoned/idle land) are required by 10 out of the 472 special species and are important for several of the game species and habitat generalist species. These habitats can result from even-aged regeneration harvests, group selection harvests, disturbance (i.e., insect, disease, fire), and from once cultivated, now untended lands. These habitats succeed rapidly into sapling forests and so are not very abundant. The landscape principles of isolation, patch size, and source/sink communities are ways of maintaining these habitats.
Analyses revealed 31 rare community classes in the Southern Appalachians: beaver pond and wetland complexes, beech gap forests, boulder fields (forested), calcareous cliffs, calcareous woodlands and glades, Carolina hemlock forest, caves, granitic domes, granitic flatrocks, grassy balds (fig. 57), heath balds, high-elevation rocky summits, mafic and calcareous fens, mafic cliffs, mafic woodlands and glades, mountain lakes, mountain longleaf pine woodlands, mountain ponds, river gravel cobble bars, sandstone cliffs, seasonally dry sinkhole ponds, serpentine woodlands and glades, shale barrens, sinkholes and karstlands, sphagnum and shrub bogs, spray cliffs, spruce-fir forests, swamp forest-bog complexes, Table Mountain pine-pitch pine woodlands, talus slopes (nonforested), and wet prairies.
Figure 57
High elevation grassy balds are one of 31 rare communities and
streamside habitats that provide habitat for 84 percent of the
federally listed plants and animal species.
Natural Processes and Human-Caused
Disturbances to Ecosystems
Human-caused disturbances, such as introduction of exotic plants and diseases, extirpation of species, or utilization of natural resources, raise special concerns because their long-term consequences often are unknown. Natural disturbances that currently affect ecosystems are probably similar to past disturbances, whereas human disturbances may be very different than those in the past.
The use of fire by Native Americans and later settlers
significantly altered Southern Appalachian forests for hundreds
of years. Fire prevention and suppression in the 20th century,
therefore, has changed a long-term pattern, and there are
ecological consequences.
Fire is probably the most common form of natural disturbance in most of the ecosystems of the Southern Appalachians. It is particularly important in systems dominated by southern yellow pines, and its ecological effects in those systems are well understood. Effects in dry deciduous forests also are important but are less understood. Fire probably was a major factor in the development of oak forests on upland sites.
In the absence of fire, two rare forest communities in the Southern Appalachians - mountain longleaf pine woodlands and Table Mountain pine-pitch pine woodlands - are being replaced by hardwoods and loblolly pine. The endangered red-cockaded woodpecker is associated with longleaf pine woodlands in northeastern Alabama and northwestern Georgia. Table Mountain pine has cones that open only when exposed to high temperatures from fires. Fire exclusion, therefore, will cause continued decline of this community.
Other forest types and plant communities where fire plays a role in community dynamics include: yellow birch boulder fields, high-elevation red oak, montane oak-hickory, white pine, chestnut oak, dry to mesic oak-hickory, xeric shortleaf pine, xeric Virginia pine, heath balds, grassy balds, ultramafic barrens, and bogs.
Logging and other land use practices of the past have affected the age class distribution on national forests. At present, a large percentage of the stands on national forests are 60 to 90 years old. This condition may increase the severity of insect and disease outbreaks in some forest types. Current rates of disturbance from timber harvesting and other forest management activities on national forests appear to be low when compared to estimates of disturbance before European settlement and estimates based on descriptions of land use patterns in the late 19th and early 20th centuries.
In addition to fire exclusion, recent human-caused disturbances include introduction of exotic pests, such as chestnut blight, gypsy moth, Dutch elm disease, balsam and hemlock woolly adelgids, many exotic plants, and feral hogs. The interaction of human-caused disturbances with natural events has produced a landscape that probably is unlike any that occurred in the past.
Figure 59
Dogwood anthracnose is found in every county in the Southern
Appalachians.
Figure 60
Hemlock woolly adelgid threatens to spread throughout the
range of Carolina hemlock.
Butternut is under attack by the butternut canker. Infected trees eventually are killed, and very limited resistance to the disease has been found. Butternut trees on national forests are being protected from logging, but many private landowners have cut their butternut trees to get income from them before the disease strikes.
The loss of American chestnut to chestnut blight is a well-known story. The ecological effects of the loss of this species were large and may still be occurring. This disease reduced American chestnut and Allegheny chinquapin to shrub species.
American elms in forests are killed by Dutch elm disease, but the effects are less apparent than when urban shade trees die. The importance of American elm in forest ecosystems is unknown.
Table Mountain pine is declining in the Southern Appalachians. It is relatively rare to find stands of this fire-dependent, serotinous-coned species. Death is often caused by bark beetles, but the species is failing to reproduce because fire is being excluded.
Figure 62
Oak decline is caused by many factors and species in the red
oak group are the most susceptible.
Figure 63
The European gypsy moth is expected to continue to spread
southward.Introduction of exotic plant species have caused some
disruptions in some Southern Appalachian ecosystems.
Introductions of exotic plant species have caused some disruptions in some Southern Appalachian ecosystems. Extensive programs may be needed to manage, control, or eradicate these species.
Management of the area's national forests in the first half of this century concentrated on reforestation of cutover land and former agricultural land, watershed improvement, erosion control, and fire protection. Vigorous regrowth, restoration of watersheds, and expansion of wildlife populations were obvious and had satisfying results.
The biggest forest health problems in the Southern Appalachians today are gypsy moths in northern Virginia, oak decline throughout the region, and southern pine beetles in the southern quarter of the region. These agents increase tree mortality, reduce growth, and eventually change species composition.
Treatments could be imposed to improve vigor of individual trees and mitigate the effects of oak decline. Evolving markets for low quality trees and strong markets for high quality oak timber could create profitable opportunities to improve forest health.
Gypsy moth impacts could be reduced through: (1) risk rating to identify vulnerable stands, and thinning and salvage cutting (2) quarantine to prevent introduction into uninfested areas, (3) careful monitoring of the spread of the insect. Biological controls of gypsy moths include mass trapping of males, mating disruption through pheromone releases, release of sterile insects, and the use of biological agents. Chemical control agents include diflubensuron and acephate.
Impacts of southern pine beetles can be reduced by determining risks of attack in individual stands and treating the stands where risks are high. Existing infestations can be stopped by cutting and leaving infested trees, cutting and removing them, or cutting and burning them. Biological control methods include enhancement of habitat for parasites and predators of the beetles. Dursban and lindane are insecticides used against southern pine beetles.
Genetic conservation seems desirable for tree species that might be destroyed by exotic pests. Species at risk include American chestnut, Allegheny chinquapin, butternut, Fraser fir, flowering dogwood, and eastern and Carolina hemlock. Backcrossing to create resistant hybrids may be feasible for American chestnut, butternut, and hemlock.
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