This ecoregion is located in the plains and hill country west of the Appalachians in northwest Alabama and east central Tennessee, eastern Kentucky, western North Carolina and Virginia, most of West Virginia, western Maryland, southeastern Ohio and western Pennsylvania. This ecoregion also occurs in scattered disjuncts in the Ozark and Ouachita Mountains of Arkansas, Missouri, and extreme eastern Oklahoma.[3] These forests are known for their rich diversity of plants and animals, which is due to several contributing factors, especially that the area was an unglaciated refugium for many species. It shares species with the high elevation Appalachian-Blue Ridge forests to the east, the hardwood forests to the west, and the mixed hardwood/conifer forests to the south.
They are one of the most biologically diverse temperate forest regions on earth. It has an unusually diverse tree flora, with as many as 30 tree species at a single site including many relics of the ancient forest that once covered North America more widely. Along with the forest there is a rich undergrowth of ferns, fungi, herbaceous plants, shrubs and small trees as well as areas of glade, heath, shale, peat bog and cranberry bog.
Spruce-fir forests occur at the highest elevations, above 3,200 feet (980 m). Their environment is cool and wet, with frequent fog and precipitation. Red spruce (Picea rubens) and Fraser fir (Abies fraseri) dominate the forest canopy.[12]
Bogs
Cranberry bogs harbor species typical of ecoregions found to the north. These species include cranberry and blueberry (Vaccinium spp.), bog rosemary (Andromeda glaucophylla), and buckbean (Menyanthes trifoliata). These bogs are relicts that have survived since the last glacial period.
Other habitats
More unique, restricted habitats within these forests include glades, heath barrens, shale barrens, and sphagnum bogs. These often support endemic plants and land snails.
Prehistoric period
During the Last Glacial Maximum about 18,000 years ago, the influence of Arctic air masses and boreal vegetation extended to about 33° N. latitude, the approximate latitude of Birmingham and Atlanta. Forests of the glacial period were dominated by various spruces (Picea spp.) and jack pine; fir (Abies spp.) was abundant in some locations. With the exception of the absence of certain prairie elements, the understories of these forests were generally typical of modern spruce-fir forests within and near Canada. Temperate deciduous forests dominated from about 33° to 30° N. latitude, including most of the glacial Gulf Coast from about 84° W. longitude. Regional climate was similar to or slightly drier than modern conditions. Oak, hickory, chestnut, and southern pine species were abundant. Walnuts, beech, sweetgum, alder, birch, tulip poplar, elms, hornbeams (Carpinus spp.), basswoods, and others that are generally common in modern southern deciduous forests were also common then. Grasses, sedges, and sunflowers were also common.
The woodlands of the area are rich in wildlife. In particular they are important habitat for migrating birds including wood warblers, vireos, and thrushes. The rivers of the ecoregion have the highest species richness of any freshwater ecosystem. In particular, there are a large number of endemic fish and shellfish species.
Threats
This ecoregion is considered critically endangered with 95% of the habitat degraded or converted to commercial forest. Large areas have been destroyed and fragmented through surface mining, including mountaintop removal. Large areas have also been logged and then converted to plantations of fast-growing tree species, such as Loblolly Pine (Pinus taeda) which are then used to produce wood pulp, which is particularly a problem in the Cumberland Plateau of Tennessee. Another threat to habitats come from growing numbers of deer. Major rivers in the ecoregion, such as the Tennessee River, have been dammed. This has resulted in the threatened or endangered status of many species of native fish, amphibians, and shellfish.
Natural areas
The remaining forest is mostly found in protected areas.
