Chapter 4 Habitats
An increase in frequency and intensity of storms due to climate change will have a similar impact on stream systems by increasing pollutant loading. Increased storm intensity that causes flooding can lead to increased stormwater runoff and erosion. With increased stormwater runoff, there is an increase in loading of sediments, nutrients, and contaminants into streams and potential negative effects on biota, such as fish kills. With a change in intensity and variability of rainfall, there are potential changes to stream flow patterns, channel hydrodynamics, and the volume of groundwater (Band and Salvesen 2009; USEPA 2010; Bakke 2009) . 4.2.3.4 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 coldwater systems, a combination of synergistic effects with development and lack of forested riparian corridors could stress these systems to the point where several species are unable to persist. Table 4.2.3-2 provides the results of a vulnerability assessment completed by the NCNHP (2010) for coldwater systems that compare climate change impacts in order of importance with other types of potential or known threats.
Table 4.2.3-2. Climate change compared to other threats to coldwater systems.
Rank Order
Threat
Comments
1 Direct, secondary, and cumulative effects from development. Residential development, particularly in steep slope areas, is of particular concern because of increased erosion. 1 Lack of riparian vegetation or inadequate width of forested buffers can cause streambank erosion and sedimentation. Vegetation also provides shading that reduces water temperature and is a source of detritus that is a food resource for macrobenthic species. 2 Point and nonpoint sources—runoff and EDCs—are threats. Recent studies have shown EDCs in treated wastewater can inhibit reproduction and cause feminization of mussels and fish. Christmas tree farms use high amounts of herbicides and pesticides that may persist in soil for long periods of time or run off into streams. 2 Livestock access to streams contributes heavily to bank erosion, sedimentation, and nutrient input. 3 Coldwater systems may shrink in habitat and extent, making small streams more vulnerable to water temperature increases because of their low thermal capacity ( Caissie 2006 ). 4 Water withdrawals can be problematic, particularly in streams with already low 7Q10 flows, because they may reduce available habitat for aquatic species. Irrigation withdrawals pose a threat to flow regime.
Development
Lack of riparian vegetation
Pollution
Cattle in Streams
Climate Change
Water Withdrawals
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2025 NC Wildlife Action Plan
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