| Appalachian mixed mesophytic forests | |
|---|---|
 Hanson's Point in theRed River Gorge,Kentucky | |
 | |
| Ecology | |
| Realm | Nearctic |
| Biome | Temperate broadleaf and mixed forest |
| Borders | |
| Bird species | 200[1] |
| Mammal species | 73[1] |
| Geography | |
| Area | 192,200 km2 (74,200 sq mi) |
| Country | United States |
| States | |
| Climate type | Humid continental (Dfb),humid subtropical (Cfa) andoceanic climate (Cfb)[failed verification][2] |
| Conservation | |
| Global 200 | Yes |
| Habitat loss | 14.8%[1] |
| Protected | 8.37%[1] |
TheAppalachian mixed mesophytic forests is anecoregion of thetemperate broadleaf and mixed forestsbiome, as defined by theWorld Wildlife Fund. It consists ofmesophytic plants west of theAppalachian Mountains in theSoutheastern United States.
This ecoregion consists of the followingEPA level III ecoregions:
This ecoregion is located in the plains and hill country west of the Appalachians in northwestAlabama and east centralTennessee, easternKentucky, westernNorth Carolina andVirginia, most ofWest Virginia, westernMaryland, southeasternOhio and westernPennsylvania. This ecoregion also occurs in scattered disjuncts in theOzark andOuachita Mountains ofArkansas,Missouri, and extreme easternOklahoma.[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 unglaciatedrefugium for many species. It shares species with the high elevationAppalachian-Blue Ridge forests to the east, thehardwood forests to the west, and the mixed hardwood/conifer forests to the south.
The climate varies fromhumid continental in the north tohumid subtropical in the south.
They are one of the most biologically diversetemperate forest regions on earth. It has an unusually diverse treeflora, with as many as 30 tree species at a single site including many relics of the ancient forest that once coveredNorth America more widely. Along with the forest there is a rich undergrowth offerns,fungi,herbaceous plants,shrubs and small trees as well as areas ofglade,heath,shale,peat bog andcranberry bog.
Mesophytic forests are found on deep and enriched soils in sheltered topography such as coves and low-elevation slopes. They are often found near small streams. Theherb layer is very rich and, in undisturbed areas, the trees can grow very large. Typical trees include sugar maple (Acer saccharum), beech (Fagus grandifolia), tuliptree (Liriodendron tulipifera), basswood (Tilia americana), northern red oak (Quercus rubra), cucumber tree (Magnolia acuminata), and black walnut (Juglans nigra). Other trees found here are eastern hemlock (Tsuga canadensis), white ash (Fraxinus americana), sweetgum (Liquidambar styraciflua), and yellow buckeye (Aesculus flava).[4]
Thesouthern Ridge and Valley/Cumberland dry calcareous forests occur on dry to dry-mesiccalcareous habitats on lowescarpments of theCumberland Plateau. They are often found on deep soils in a variety landscapes within their range. Trees are mainly oaks and hickories, with other species less abundant. Oaks include white oak (Quercus alba), northern red oak (Quercus rubra), post oak (Quercus stellata), chinkapin oak (Quercus muehlenbergii), and Shumard oak (Quercus shumardii). Hickories include shagbark hickory (Carya ovata). Other trees can be sugar maple (Acer saccharum), eastern red-cedar (Juniperus virginiana), or pines.[5]
Appalachian cove forests are found in sheltered concave slopes with a moist environment. Characteristic tree include yellow buckeye (Aesculus flava), sugar maple (Acer saccharum), white ash (Fraxinus americana), basswood (Tilia americana), tuliptree (Liriodendron tulipifera), Carolina silverbell (Halesia tetraptera), eastern hemlock (Tsuga canadensis), beech (Fagus grandifolia), cucumber tree (Magnolia acuminata), and Fraser magnolia (Magnolia fraseri).[6]
Dry-mesic oak forests cover large areas at lower and middle elevations on flat to gently rolling terrain. Mature stands have a variety of oak and hickory species adapted to dry-mesic conditions. Oaks include northern red oak (Quercus rubra), white oak (Quercus alba), black oak (Quercus velutina), and scarlet oak (Quercus coccinea); hickories include mockernut hickory (Carya tomentosa), shagbark hickory (Carya ovata), red hickory (Carya ovalis), and pignut hickory (Carya glabra). In addition, red maple (Acer rubrum), sweet birch (Betula lenta), and yellow birch (Betula alleghaniensis) are common; sugar maple (Acer saccharum) is occasional. In areas that have been recently disturbed, white pine (Pinus strobus), Virginia pine (Pinus virginiana), black locust (Robinia psuedoacacia), or tulip tree (Liriodendron tulipifera) can be abundant. Areas of impeded drainage sometimes harbor small wetlands, including non-forestedseeps or forested wetlands with red maple (Acer rubrum), swamp white oak (Quercus bicolor), or black tupelo (Nyssa sylvatica).[7] Sprouts of American chestnut (Castanea dentata) are common in these forests.
TheAllegheny-Cumberland dry oak forest and woodland forest system is found on acidic soils on theAllegheny andCumberland plateaus, and ridges in the southernRidge and Valley. The forests are typically dominated by white oak (Quercus alba), southern red oak (Quercus falcata), chestnut oak (Quercus prinus), scarlet oak (Quercus coccinea), with lesser amounts of red maple (Acer rubrum), pignut hickory (Carya glabra), and mockernut hickory (Carya tomentosa). A few shortleaf pines (Pinus echinata) or Virginia pines (Pinus virginiana) may occur, particularly adjacent toescarpments or following fire. Sprouts of chestnut (Castanea dentata) can often be found where it was formerly a common tree.[8]
Southern Appalachian low-elevation pine forests occur on a variety of topographic and landscape positions, including ridgetops, upper- and mid-slopes, and in lower elevations (generally below 2,300 feet (700 m)) such as mountain valleys. These forests dominated by shortleaf pine (Pinus echinata) and Virginia pine (Pinus virginiana). Pitch pine (Pinus rigida) may sometimes be present. Hardwoods are sometimes abundant, especially dry-site oaks such as southern red oak (Quercus falcata), chestnut oak (Quercus prinus), and scarlet oak (Quercus coccinea), but also pignut hickory (Carya glabra), red maple (Acer rubrum), and others. Theshrub layer may be well-developed, with hillside blueberry (Vaccinium pallidum), black huckleberry (Gaylussacia baccata), or other acid-tolerant species most characteristic. Herbs are usually sparse but may include narrowleaf silkgrass (Pityopsis graminifolia) and Goat-rue (Tephrosia virginiana).[9]
Montane oak forests occur on exposed ridges and on south- to west-facing slopes at middle elevations. Soils are thin and nutrient-poor and trees are often stunted and wind-flagged. Northern red oak (Quercus rubra) and white oak (Quercus alba) are common, as are sprouts of American chestnut (Castanea dentata). Winterberry (Ilex montana), flame azalea (Rhododendron calendulaceum), catawba rhododendron (Rhododendron catawbiense), and great rhododendron (Rhododendron maximum) are common shrubs.[10]
Hemlock-northern hardwood forests are found at higher elevations. They include yellow birch (Betula alleghaniensis), mountain maple (Acer spicatum), sugar maple (Acer saccharum), beech (Fagus grandifolia), and eastern hemlock (Tsuga canadensis). Mountain laurel (Kalmia latifolia) and rhododendron (Rhododendron spp.) are found in the understory.[11]
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]
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 lastglacial period.
More unique, restricted habitats within these forests includeglades,heath barrens,shale barrens, andsphagnum bogs. These often support endemic plants and land snails.
During theLast 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 ofBirmingham andAtlanta. Forests of the glacial period were dominated by various spruces (Picea spp.) andjack 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 nearCanada.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, andsunflowers were also common.
The woodlands of the area are rich in wildlife. In particular they are important habitat for migrating birds includingwood warblers,vireos, andthrushes. The rivers of the ecoregion have the highest species richness of anyfreshwater ecosystem. In particular, there are a large number ofendemic fish and shellfish species.
This ecoregion is considered critically endangered with 95% of the habitat degraded or converted to commercial forest. Large areas have been destroyed and fragmented throughsurface mining, includingmountaintop removal. Large areas have also been logged and then converted toplantations of fast-growing tree species, such asLoblolly Pine (Pinus taeda) which are then used to producewood pulp, which is particularly a problem in theCumberland Plateau ofTennessee. Another threat to habitats come from growing numbers ofdeer. Major rivers in the ecoregion, such as theTennessee River, have been dammed. This has resulted in the threatened orendangered status of many species of native fish, amphibians, andshellfish.
The remaining forest is mostly found in protected areas.
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