Chapter 4 Habitats
systems and can exacerbate DO problems, particularly when flows are low (DeWan et al. 2010; Karl et al. 2009; Band and Salvesen 2009; USEPA 2010) .
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 streamflow patterns, channel hydrodynamics, and the volume of groundwater (Band and Salvesen 2009; USEPA 2010; Bakke 2008) . Drought conditions over the past several years have required many municipalities to evaluate their water supply and capacity to meet demand. Residential and commercial growth in urban areas generates new demands for water supplies. An increase in the number of proposed reservoirs and surface water withdrawals is a potential consequence of reduced water supply and increased demand. Potential changes in storm frequency and intensity will likely alter channel hydrodynamics, specifically 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) . 4.2.9.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help define short- and long-term conservation actions and recommendations. In the past, aquatic systems have been under threat from a variety of perturbations and many of those continue today. Conversion of land, both from forest to agriculture or silviculture, as well as from development projects, continues to threaten stream integrity resulting in increased sediment, bank erosion, and stormwater runoff containing sediment and other potentially toxic materials. Considering current conditions in these systems, climate change is likely to have a synergistic effect with other threats that are of more immediate concern. Table 4.2.9-1 provides a review of expected climate change impacts in order of importance in comparison with other types of threats.
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2025 NC Wildlife Action Plan
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