Chapter 4 Habitats
limited or restricted, access to or availability of cooler water habitats may limit the range of those species subject to narrow temperature tolerance (DeWan et al. 2010) . 4.2.4.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help define short- and long-term conservation actions and recommendations. Aquatic systems have been under threat from a variety of perturbations in the past 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 4.2.4-1 provides a review of expected climate change impacts in order of importance in comparison with other types of threats.
Table 4.2.4-1 Climate change compared to other threats to coolwater systems.
Rank Order
Threat
Comments
1 Residential development, especially in steep slope areas, is of particular concern because of increased erosion. Most coolwater streams are larger streams and rivers, and many have wider valleys where land use is more susceptible to being developed than on steeper-sloped headwater streams. Row crops, agricultural grazing, and urban/suburban development are common. Increased presence of impervious surfaces due to roads, parking lots, homes, and businesses increases the amount and speed of runoff being delivered into aquatic systems. 1 Stormwater runoff will amplify the loading of nutrients, sediment, and contaminants into streams, rivers, and reservoirs, which may alter overall channel design; have a negative effect on biota due to habitat changes, increased turbidity, and chemical exposure; and affect drinking water quality (Band and Salvesen 2009) . 1 Runoff from urban areas often contains higher concentrations of nutrients (such as nitrogen and phosphorus), sediment, metals, hydrocarbons, and microbes. An increase in frequency and intensity of storms due to climate change will have a similar impact on stream systems by increasing pollutant loading. Point and nonpoint sources— runoff and EDCs—are also threats. 1 Livestock access to streams contributes heavily to bank erosion, sedimentation, and nutrient input. 1 Riparian vegetation serves as nutrient input to the stream community and helps regulate stream temperature by providing shade. Lack of
Development
Sediment and Erosion
Pollution
Cattle in Streams
Lack of riparian vegetation
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2025 NC Wildlife Action Plan
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