Effects of Land Use and Disturbance on Benthic Insects in Headwater Streams Draining Small Watersheds North of Charlotte, NC

Abstract Increasing development north of Charlotte, NC, threatens aquatic life in streams by reducing riparian zones and increasing runoff. Runoff, sedimentation from erosion, and poor construction practices are principal sources of pollution. We asked how land use and disturbance affected benthic insects. We visited nine streams from May to October 2001, collected data on insect diversity, chemistry, and physical habitat. We used a Geographic Information System to delineate watersheds and land use patterns. Watersheds were categorized based on land use, abiotic variables, and disturbance. Insect communities were more diverse in streams draining low disturbance watersheds than in streams draining highly developed watersheds. Sensitive taxa were found in streams with extensively forested watersheds, but were nonexistent in extensively developed watersheds. Disturbances occurring in streams caused declines in diversity, often eliminating sensitive taxa. Aquatic insect diversity is related to land use patterns and disturbances, and anthropogenic alteration of habitat has negative consequences to that diversity.