National Water Summary-Wetland Resources 297 North Carolina Wetland Resources Wetlands of North Carolina are diverse and widely distributed. deepwater habitats. Wetlands of the systems that occur in North About 5. 7 million acres, or 17 percent. of the State is covered by Carolina are described below. wetlands (Dahl, 1990). About 95 percent of these wetlands are in the eastern part of the State (fig. l). Wetland description Wetlands affect streamtlow and water quality and provide criti­ System cal habitat to a variety of plants and an imals. Because of the large Palustrine .................. Nontidal and tidal-freshwater wetlands in which size of some eastern North Carolina wetlands and their proximity vegetation is predominantly trees (forested wet­ lands); shrubs (scrub-shrub wetlands); persistent to coastal waters, these wetlands are important regulators of fresh­ or nonpersistent emergent, erect, rooted herba­ water, nutrient, and sediment inputs to North Carolina estuaries. ceous plants (persistent- and nonpersistent­ Almost one-halfof North Carolina's wetlands are bottom-land hard­ emergent wetlands); or submersed and (or) wood forests, which are valuable habitats for waterfowl breeding floating plants (aquatic beds). Also, intermit­ and overwintering and for anadromous fish spawning (U.S. Fish and tently to permanently flooded open-water bod­ ies of less than 20 acres in which water is less Wildlife Service, 1992). About 90 percent of the State's commer­ than 6.6 feet deep. cial fish harvest is derived from estuary-dependent species. Tidal Lacustrine ................. Wetlands within an intermittently to permanently and nontidal creeks surrounded by wetlands and vast beds of sub­ flooded lake or reservoir larger than 20 acres and mersed aquatic vegetation function as nursery areas for larval and (or) deeper than 6.6 feet. Vegetation, when juvenile fish and provide critical finfish and shellfish habitats for present, is predominantly nonpersistent emer­ gent plants (nonpersistent-emergent wetlands), adults. Small wetlands throughout the Piedmont and Blue Ridge or submersed and (or) floating plants (aquatic Provinces of the State harbor at least 80 species of rare or endan­ beds), or both. gered plants. Statewide. about 70 percent of the rare and endangered Riverine ..................... Nontidal and tidal-freshwater wetlands within a plants and animals depend on wetlands. channel. Vegetation, when present, is same as in the Lacustrine System. TYPES AND DISTRIBUTION Estuarine ................... Tidal wetlands in low-wave-energy environments where the salinity of the water is greater than 0.5 Wetlands are lands transitional between terrestrial and part per thousand (ppt) and is variable owing to evaporation and the mixing of seawater and deepwater habitats where the water table usually is at or near the freshwater. land surface or the land is covered by shallow water (Coward in and Marine ....................... Tidal wetlands that are exposed to waves and cur- others, 1979). The distribution of wetlands and deepwater habitats rents of the open ocean and to water having a in North Carolina is shown in figure 2A; only wetlands are discussed salinity greater than 30 ppt. herein. Wetlands can be vegetated or nonvegetated and are classified Palustrine system.- Palustrine wetlands account for most of on the basis of their hydrology, vegetation, and substrate. In this the wetland acreage in North Carolina. Palustrine wetlands in the summary, wetlands are classified according to the system proposed State include forested wetlands (bottom-land hardwood forests, by Coward in and others ( 1979), which is used by the U.S. Fish and fringe wooded swamps, wet pine tlatwoods, pine savannas, and Wildlife Service (FWS) to map and inventory the Nation's wetlands. hardwood flats), wetlands that are classified as forested or scrub­ At the most general level of the classification system, wetlands are shrub wetlands, depending on the characteristics of the dominant grouped into five ecological systems: Palustrine, Lacustrine, Riv­ vegetation (Carolina bays, pocosins, and bogs), and emergent wet­ erine, Estuarine. and Marine. The Palustrine System includes only lands (nontidal and tidal fresh marshes). wetlands, whereas the other systems comp rise wetlands and Bottom-land hardwood forests cover about 2.7 million acres (U.S. Fish and Wildlife Service, 1992) and occur primarily in the Coastal Plain along the Roanoke, Tar, Neuse, and Cape Fear Riv­ ers, as well as along other large interior streams (fig. 2A and 28). The Roanoke River flood plain has one of the largest and least dis­ turbed bottom-land hardwood forests in the mid-Atlantic region. Cypress, swamp gum, and black gum grow in the wetter areas of the flood plain, whereas temporarily or seasonally flooded bottom­ land hardwood-forest wetlands are dominated by red maple, green ash, elm, sycamore, and sweet gum. Fringe wooded swamps are the dominant shoreline type around Albemarle Sound; along the Alligator, Scuppernong, and lower Chowan Rivers; and in some locations along tributaries to Pamlico Sound. These swamps cover an area of about 400.000 acres (North Carolina Department of Environment, Health, and Natural Re­ sources, l 994) and are vegetated primarily by cypress (Environmen­ tal Defense Fund, 1989). Wet pine flatwoods possibly occupy more than 2 million acres, Figure 1. Merchants Millpond, a forested wetland in and pine savannas cover an area of about 28,000 acres (North Caro­ northeastern North Carolina. (Photograph by Virginia lina Department of Environment, Health, and Natural Resources, Carter, U.S. Geological Survey.) 1994). Both ecosystems have a canopy of longleaf pine and occa- 298 National Water Summary-Wetland Resources: STATE SUMMARIES sional loblolly pine with an understory of wiregrass. Pine savannas such as titi and yaupon, thorny vines, and occasional taller pond have a greater density of trees than wet pine flatwoods, and pine pines projecting above the thicket. Forested pocosins are generally savannas support orchids and various small vascular plants, such dominated by red bay, sweet bay, Atlantic white cedar, loblolly bay, as pitcher plants, Venus flytrap, and sundews. Wet pine flatwoods and pond pine (Sharitz and Gibbons, 1982; Ash and others, 1983). are common throughout the western and middle regions of the Vegetation in large pocosins commonly grows in zones with shorter Coastal Plain, except in the Sand Hills, whereas pine savannas are vegetation in the center. most common in the southeastern corner of the State (Schafale and Other types of palustrine wetlands include bogs and fresh Weakley, 1990). marshes. Bogs, which occur throughout the Blue Ridge Province, Carolina bays are ovate depressions that occur across the have been subject to draining, impoundment, and clearing at lower Coastal Plain but are most common in the southeastern corner of elevation sites (Schafale and Weakley, 1990). Nontidal fresh marshes the State (Sharitz and Gibbons, 1982). Most of the bays contain cover about 46,000 acres in the Coastal Plain (Field and others, palustrine wetlands, but a few large Carolina bays, such as Lake 1991 ) and often grade upriver to cypress-gum swamps ( forested Waccamaw, are lacustrine wetlands. The bays range in length from wetlands). About 2,200 acres of tidal fresh marshes exist in North about l SO feet to more than 5 miles. Because of variability in size, Carolina (Field and others, 1991). depth, location, and substrate, Carolina bays are not characterized Lacustrine and Riverine Systems. - Lacustrine wetlands com­ by a single vegetation type. These systems are unusual in their geo­ prise the shallows of natural lakes and reservoirs where there is no graphic orientation (northwest to southeast) and consistent shape persistent emergent vegetation or trees. All of the State's natural lakes (narrower at the southeast end). are located in the Coastal Plain, and many are associated with Caro­ About 700,000 acres of pocosins remain in North Carolina lina bays or peatlands. More than I 00 water-supply and flood-con­ (Environmental Defense Fund, 1989)-about 70 percent of the trol reservoirs have been constructed throughout the Piedmont and Nation's pocosin wetlands (Richardson and others, 1981 ). Pocosins Blue Ridge Provinces (North Carolina Department of Environment, form in poorly drained basins, including interior depressions of Health, and Natural Resources, 1992). Riverine wetlands constitute Carolina bays (Ash and others, 1983). The typical pocosin is clas­ the entire channel of small, shallow streams and shallow areas near sified as a scrub-shrub wetland. However, a pocosin can be a for­ the banks in large, deep streams. The total area of lacustrine and ested wetland, depending on the successional stage of the pocosin, riverine wetlands in the State is not known but is small relative to which is commonly determined by hydrology or by fire and other the area of palustrine wetlands. disturbances (Hefner and Moorhead, 1991 ). Scrub-shrub pocosins Estuarine and Marine Systems.-North Carolina contains are dominated by dense, almost impenetrable, growths of evergreens more than 3,000 miles of tidal (estuarine and ocean) shoreline (Clay Piedmont Coastal Plain Sand Hills PHYSIOGRAPHIC DIVISIONS A ' ' ""' ... C, WETLANDS AND DEEPWATER HABITATS 0 Distribution of wetlands and deepwater habitats- This map shows the approximate distribution of large C, wetlands in the State. Because of limitations of scale and source material, some wetlands are not shown