General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 128X–Southern Appalachian Ridges and Valleys

MLRA 128, partially shown as the gray shaded area on the accompanying figure, falls into the East and Central Farming and Forest Region. This MLRA is in Tennessee (36 percent), Alabama (27 percent), Virginia (25 percent), and Georgia (12 percent). It makes up about 21,095 square miles (54,660 square kilometers).

Most of this MLRA is in the Tennessee Section of the Valley and Ridge Province of the Appalachian Highlands. The thin stringers in the western part of the area are mostly in the Cumberland Plateau Section of the Appalachian Plateaus Province of the Appalachian Highlands. A separate area of the MLRA in northern Alabama is in the Highland Rim Section of the Interior Low Plateaus Province of the Interior Plains. The western side of the area is dominantly hilly to very steep and is rougher and much steeper than the eastern side, much of which is rolling and hilly. Elevation ranges from 660 feet (200 meters) near the southern end of the area to more than 2,400 feet (730 meters) in the part of the area in the western tip of Virginia. Some isolated linear mountain ridges rise to nearly 4,920 feet (1,500 meters) above sea level.

The MLRA is highly diversified. It has many parallel ridges, narrow intervening valleys, and large areas of low, irregular hills. The bedrock in this area consists of alternating beds of limestone, dolomite, shale, and sandstone of early Paleozoic age. Ridgetops are capped with more resistant carbonate and sandstone layers, and valleys have been eroded into the less resistant shale beds. These folded and faulted layers are at the southernmost extent of the Appalachian Mountains. The narrow river valleys are filled with unconsolidated deposits of clay, silt, sand, and gravel.

Classification relationships

This PES may correlate with Northern Red Oak Forests and Northern Hardwood Forests according to the "The Natural Communities of Virginia, Second Approximation" (http://www.dcr.virginia.gov/natural-heritage/natural-communities/nctig). Representative community types described by NatureServe include the Central Appalachian Northern Red Oak Forest (USNVC: = CEGL008506), and the Southern Appalachian Northern Red Oak Forest (Deciduous Shrub Type), USNVC: = CEGL007300. The Southern Appalachian Northern Red Oak Forest (Evergreen Shrub Type), USNVC: = CEGL007299 may also occur on this site.

The U.S. Forest Service's ecoregional classification, Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow M221) also encompasses this PES: http://www.fs.fed.us/land/ecosysmgmt/colorimagemap/images/m221.html

The U.S. Environmental Protection Agency (EPA), classifies this PES under "Southern Sandstone Ridges" in their tier IV ecoregional classification. The Southern Sandstone Ridges region encompasses the major sandstone ridges, but these ridges also have areas of shale, siltstone, and conglomerate. The steep, forested ridges tend to have narrow crests, and the soils are typically stony, sandy, and of low fertility. The chemistry of streams flowing down the ridges can vary greatly depending on the geologic material. In Georgia and Tennessee, most of the sandstone ridges are relatively narrow, but in Alabama, the region also includes the Coosa and Cahaba ridges that are broader and of younger Pennsylvanian-age sandstone and shale. Although most all of the ridges were once logged, a variety of forest types of different ages and composition occurs here. The natural vegetation consists primarily of oak-hickory-pine forest. Red oak, chestnut oak, black oak, and some white oak communities are typical, along with pines such as loblolly pine, Virginia pine and shortleaf pine. Some pitch pine can be found on the higher, exposed ridges in the north (cite EPA).

Ecological site concept

This site occurs on moderately deep, well drained soils formed in residuum of red noncalcareous shale, siltstone, and sandstone on mountain summits, shoulders and side slopes and moderately deep, somewhat excessively drained to well drained soils formed in residuum from acid sandstone interbedded with shale and siltstone on summits and shoulders of ridges at elevations between 3,200 to 5,000 feet. Permeability is moderately rapid. Slope ranges from 0 to 80 percent. Mean annual precipitation is about 47 inches, and mean annual air temperature is about 46 degrees F.

This PES is of small extent.

Vegetation is mainly in forest. Native forest species include northern red oak, sugar maple, black cherry, white ash, American beech black birch, red maple, chestnut oak and red spruce. The understory includes striped maple, black birch, azalea, mountain laurel, ferns, black cherry, red maple, sugar maple, and witch hazel. Forestry is an important land-use.

Table 1. Dominant plant species