4.2 Aquatic Communities
4.2.10 Large River Communities 4.2.10.1 Ecosystem Description
Large river communities occur statewide and are the largest and highest order rivers in the Piedmont and Coastal Plain ecoregions. Many originate in the Piedmont and are some of the most fragmented aquatic systems because they are the site of major hydroelectric projects. After passing over the fall line that divides the Piedmont and Coastal Plain ecore- gions they transition into more typical Coastal Plain rivers with sandy substrates and wider foodplains. Large river communities are warmwater systems, where summer water tem- peratures are persistently greater than 25°C (77°F). 4.2.10.2 Location of Habitat Certain reaches of the Hiwassee, French Broad, and Little Tennessee rivers can be catego- rized as having large river communities. Examples in the Piedmont ecoregion include the Yadkin—Pee Dee River (downstream of the confuence of the South Yadkin and Yadkin rivers), Catawba River (downstream of Lake James), and the Neuse, Tar, Cape Fear, and Roanoke rivers above the Fall Line that divides the eastern Piedmont from the western Coastal Plain. Examples of large river communities in the Coastal Plain ecoregion are found in the Cape Fear, Chowan, Lumber, Neuse, Pasquotank, Roanoke, Tar–Pamlico, and White Oak River basins. Te 2005 WAP described the riverine aquatic communities as a priority habitat (see Chapter 5) (NCWRC 2005) . Adjacent terrestrial systems that may be hydrologically connected to this riverine community include foodplain forests, tidal swamp forests, and wetland communities. Tese communities provide habitat for species that rely upon rivers and streams for habitat, as well as those species which rely indirectly upon the habitat by virtue of provision of habitat for their prey. 4.2.10.3 Problems Affecting Habitats Land Use. Aquatic systems in North Carolina have been threatened by a variety of pertur- bations in the past and many of those same threats continue today. Converting land uses from natural forest to agriculture or silviculture production and residential and commer- cial development continues to threaten stream integrity because of related increases in sediment, bank erosion, and stormwater runof containing sediment and other potentially toxic materials. Riparian vegetation is critical to the overall stream and streambank stability and mod- eration of water temperatures. Lack of riparian vegetation or inadequate width of for- ested bufer can cause streambank erosion and sedimentation. In addition to stabilizing
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2015 NC Wildlife Action Plan
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