Chapter 4 Habitats
4.2.9 Medium River Communities 4.2.9.1 Ecosystem Description
Medium river communities drain watersheds 200 to 3,800 square miles in size and have coolwater systems (Section 4.2.4) where they drain Mountain ecoregion watersheds and warmwater systems (Section 4.2.5) everywhere else in the state. The Nature Conservancy notes that medium rivers have an average bankfull width of 115 feet (Anderson et al. 2014) . The aquatic communities will have a higher proportion of warmwater species relative to coolwater species (AHG 2015) . 4.2.9.2 Location of Habitat Medium river communities are found statewide in all ecoregions. Examples include Fishing Creek, Contentnea Creek, portions of Deep and Dan rivers, and the Smith, Mayo, Haw, Black, Broad, Nolichucky, Little Tennessee, and Tuckasegee rivers. Adjacent terrestrial systems that may be hydrologically connected to medium river communities include floodplain forests, tidal swamp forests, and various wetland communities. These terrestrial systems provide habitat for species that also rely upon rivers for habitat (e.g., Beaver, River Otter, various insects), as well as those species that rely indirectly upon the habitat by virtue of provision of habitat for their prey. 4.2.9.3 Problems Affecting Habitats Medium river communities in North Carolina have been threatened by a variety of perturbations in the past, similar to threats to small and large rivers, and many of those same threats continue today. Land Use. Converting land uses from natural forest to agriculture or silviculture production and residential and commercial development continues to threaten stream integrity. Deforestation and increased impervious surfaces cause increases in sedimentation, bank erosion, and stormwater runoff containing sediment and other pollutants. Erosion and the resultant sedimentation are the largest sources of nonpoint source pollution in most aquatic systems. The increased loads could affect water quality and habitat for aquatic species, as well as drinking water supplies for municipalities (Band and Salvesen 2009) . Sources of erosion include disturbance from development activities and agriculture. Residential development can increase erosion during the construction process, but also as a secondary result of increased impervious surfaces in the watershed. Most watersheds in the Piedmont are already highly developed, and development pressure is likely to increase in the Coastal Plain, which will lead to an increase in impervious surfaces, increasing runoff, stream and bank erosion, pollution inputs and increased flashiness of rivers. An increase in impervious surfaces due to roads, parking lots, homes, and businesses increases the amount and speed of
4 - 66
2025 NC Wildlife Action Plan
Made with FlippingBook Ebook Creator