Boundaries

This Appalachian Piedmont ecoregion ranges from eastern Georgia to southern Virginia, covering all of South Carolina and most of North Carolina.

Topography

Many of the rivers begin their journey to the Atlantic as small fast-flowing mountain streams in the eastern slopes of the Blue Ridge physiographic province of the Appalachian Mountains. From the hills and mountains they flow across the Piedmont Plateau until they reach the Fall Line, descending and flowing through the southern portion of the Atlantic Coastal Plain.

Freshwater habitats

As a result of the broad flat coastal plain and a high water table, this ecoregion contains an abundance of wetlands (McNab & Avers 1994). Approximately 9,816 km² of coastal marsh exist on the Atlantic Coast (Alexander et al. 1986), and roughly three-fourths occurs predominantly within this ecoregion in the states of North Carolina, South Carolina, and Georgia (Chabreck 1988). The ecoregion also includes swamps, bogs, freshwater marshes, and shallow lakes (McNab & Avers 1994). A subset of these lakes, including Lake Waccamaw, are concentrated primarily along the coast from southern North Carolina to eastern Georgia. They are collectively known as the Carolina Bays. These features were formed by the impact of extraterrestrial bodies. The unusual chemical makeup of Lake Waccamaw may be attributable to the lake’s origins, and may have played a part in the evolution of the lake’s distinctive fauna as well as its high productivity (Eyton & Parkhurst 1975; Stager & Cahoon 1987).

Terrestrial habitats

The ecoregion is dominated by oak-hickory-pine forests along the piedmont, longleaf pine (Pinus palustris) towards the south, and coastal forests that feature some of the most majestic plant communities of the United States (Ricketts et al. 1999). River swamp forests, or bottomland forests, were once prominent in this ecoregion and are characterized by bald cypress (Taxodium distichum) and swamp tupelo (Nyssa sylvatica var. biflora). Eastern or Atlantic white cedar (Chamaecyparis thyoides) occurs along blackwater rivers, most commonly on organic substrates underlain by sand (Wharton et al. 1982). Other unique communities include bogs and pocosins, which are extensive flat, damp, sandy or peaty areas far from streams with scattered pond pine (Pinus serotina) and evergreen shrubs (often gallberry, Ilex glabra) (Ricketts et al. 1999).

Description of endemic fishes

Among the endemic species are the federally endangered Cape Fear shiner (Notropis mekistocholas), restricted to a small section of the upstream portion of the Cape Fear River; the Waccamaw silverside (Menidia extensa), restricted solely to Lake Waccamaw; the Waccamaw killifish (Fundulus waccamensis), known only from Lake Waccamaw and Lake Phelps;  and the Waccamaw darter (Etheostoma perlongum), found in Lake Waccamaw and headwaters of the Waccamaw River. This concentration of endemics in and around Lake Waccamaw gives further distinction to this ecoregion, as does the large degree of endemism encountered in the Roanoke River drainage near the northern boundary of the ecoregion.

Other endemic fish include two of the six species of pygmy sunfishes in the family Elassomatidae, which is restricted to the southeastern United States (Rohde et al. 1994). These species are the blue barred pygmy sunfish (Elassoma okatie) and the Carolina pygmy sunfish (E. boehlkei). The ecoregion is also home to a newly discovered species, a relative of the golden redhorse (Moxostoma erythrurum), tentatively known as the Carolina redhorse (Moxostoma sp.) (Southeastern Fishes Council 1997).  It should be noted that new species may yet be discovered, because of all the southeastern U.S. regions, this is perhaps the least studied biologically—“a veritable black hole of life history knowledge for fishes,” according to one expert (Burkhead pers. comm.).

Justification for delineation

Ecoregion boundaries are modified from Abell et al. (2000), which based its units on subregions defined by Maxwell et al. (1995).  Modifications to this ecoregion were made following recommendations from the Endangered Species Committee of the American Fisheries Society. The James River was moved from the Chesapeake Bay [158] to the Appalachian Piedmont ecoregion based on a dissimilarity analysis that showed greater faunal similarities between the James and rivers south of it than those to the north and in the Chesapeake Bay ecoregion.