Evaluation of the Relationship between Stream Microhabitats and Taxa Traits in Piedmont Streams in North Carolina
Anthony J. Roux
Mecklenburg County Land Use and Environmental Services Agency
Program in Infrastructure and Environmental Systems, University of North Carolina Charlotte
Charlotte, NC
Co-author: Sandra M. Clinton, Department of Geography and Earth Sciences, University of North Carolina Charlotte
Stream habitat quality and benthic macroinvertebrate community diversity are negatively impacted by urbanization. As percent impervious cover (%IC) increases with development, stream channels are degraded by the increasing storm water runoff volume and intensity. Watershed managers respond to urban stream degradation by repairing degraded streams using stream restoration techniques; however, most natural channel design approaches do not result in an uplift of the benthic macroinvertebrate community. To better inform restoration design and evaluation, we investigated the relationship between stream microhabitats and benthic macroinvertebrate community diversity and function by evaluating microhabitats in 10 streams in the Piedmont, North Carolina with good habitat quality. Using the Mecklenburg Stream Habitat Assessment Protocol (MHAP), the habitat quality of these streams were rated as Partially Supporting to Supporting, receiving habitat scores ranging from 137 to 168. In comparison, in 2015, impaired urban streams in Charlotte, NC received an average MHAP score of 86.4. We collected benthic macroinvertebrates from 7 microhabitats, including riffles, root wads, leaf packs, woody debris, undercut banks, backwater, and sandy areas to correlate taxa and their traits, such as functional feeding groups, thermal preferences and habit preferences, with each microhabitat. Riffles were the most diverse microhabitat in terms of taxa (44) and diversity (2.7). Leaf packs, root wads, and woody debris were microhabitats that also supported abundant taxa (29, 21 and 19 respectively) and good diversity (2.7, 2.6 and 2.3). Sand and undercut banks were less productive habitats with fewer taxa (8 and 10) and lower diversity (1.5 and 2.1). We found that many taxa traits were redundant among the microhabitats. A high level of redundancy among traits tend to increase the resiliency of the stream ecosystem enabling the ecosystem to resist disturbances and maintain ecosystem functions. By correlating the species traits with specific microhabitats, we can better evaluate the success of stream restorations in restoring stream function and in stimulating benthic macroinvertebrate community recovery.
About Anthony J. Roux
Anthony Roux is a Senior Environmental Specialist in the Water Quality Program of the Charlotte-Mecklenburg Storm Water Services and a Ph.D. student in the Infrastructure and Environmental Systems Program at the University of North Carolina at Charlotte. He has worked at CMSWS for 37 years and has supervised the Mecklenburg County State Certified Biological Laboratory for the past 28 years coordinating the stream bioassessment program (fish, benthic macroinvertebrates, and algae). Mr. Roux has worked with the Charlotte-Mecklenburg Storm Water Services to evaluate the various stream restoration projects in Charlotte and Mecklenburg County. He is currently pursuing a Ph.D. in Ecological Engineering at UNC Charlotte studying the impact of urbanization on stream biodiversity and ecosystem function. He has a B.S. in Biological Life Sciences, a B.S. in Zoology, and a M.S. in Zoology from North Carolina State University and a M.S. in Aquatic Ecology from the University of Notre Dame. He is a certified taxonomist for Eastern Mayflies, Stoneflies, Caddisflies through the Society for Freshwater Science.