Chapter 4 Habitats
Because of potential changes in storm frequency and intensity, it is likely that channel hydrodynamics will be altered. Associated with channel hydrodynamics are changes in flow regime, sediment transport, and overall channel design. The current pattern of riffles, runs, and pools may be altered, creating changes in aquatic species’ habitats. Increased storm intensity may cause increased erosion with large amounts of sediment that move downstream, which can then deposit into pools or bury riffles. Additionally, storms may cause the felling of riparian trees, particularly in areas with narrow riparian areas. Increased woody debris in these streams will also change channel hydrodynamics as well as available habitat. Determining how or if species adapt to changing habitats will require close monitoring to observe trends and to help inform future management decisions (Bakke 2008) . 4.2.8.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help define short- and long-term conservation actions and recommendations. While climate change is not the most severe threat to large creeks and small rivers, a combination of the synergistic effects that come with development and lack of riparian corridors could stress these systems to the point where several species are unable to persist. Table 4.2.8-1. Climate change compared to other threats to large creeks/small rivers. Threat Rank Order Comments
Development causes direct, secondary, and cumulative effects. Residential development can increase erosion during the construction process and as a secondary result of increased impervious surfaces in the watershed. Growth and development increase water supply demands, and streamflow patterns are being altered due to rapid urbanization. An increase in impervious surfaces due to roads, parking lots, homes, and businesses also increases the amount and speed of runoff being delivered into aquatic systems. Decreased groundwater recharge between storms due to impervious surfaces contributes to reductions in stream baseflow.
Development
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1 Loss of riparian vegetation contributes to streambank erosion and sedimentation. Riparian vegetation serves as a food/nutrient input to the stream community and helps regulate stream temperature by providing shade. 2 Erosion and the resultant sedimentation are the largest sources of nonpoint source pollution in most aquatic systems. Runoff from urban areas often contains higher concentrations of nutrients (such as nitrogen and phosphorus), sediment, metals, hydrocarbons, and microbes. Point and nonpoint sources—runoff and EDCs—are also threats.
Lack of riparian vegetation
Pollution
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2025 NC Wildlife Action Plan
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