Characterization of aquatic macroinvertebrate communities within the Obed Wild and Scenic River system.

摘要

The Obed Wild and Scenic River is part of the Emory River Watershed, located within the Cumberland Plateau and Cumberland Mountains of east Tennessee. This watershed totals over 2,065 km of streams and includes portions of five drainages: Obed River, Clear Creek, White Creek, Daddys Creek, and Emory River. As part of the National Park Service system, biological integrity must be maintained in the Obed Wild and Scenic River. However, macroinvertebrates have not been monitored, and comprehensive taxa lists do not exist. The objectives of this study are to develop a comprehensive list of aquatic insect species inhabiting the Obed National Wild and Scenic River, determine longitudinal variation in the benthic community, compare biological condition scores between genus and species level identifications, and determine land use influence on benthic community quality.;Aquatic macroinvertebrates were collected from 21 sites using semi-quantitative (SQKICK) techniques and were identified to the lowest possible taxon. Biological condition scores were calculated using both genus and species level identification. Macroinvertebrate community data were analyzed using the ANOSIM and SIMPER routines within PRIMER software. Linear regression was used to determine the influence of land use and habitat variables on biological condition scores.;A total of 167 species was collected. Mean biological condition scores, calculated with genus and species level identification, indicated non-impaired biological conditions. Benthic community dissimilarity existed between third and fourth order and third and sixth order streams. Hydropsyche betteni, Procloeon sp., and Leuctra sp. were responsible for most of the dissimilarity between third and fourth order streams; and Procloeon sp., Nigronia serricornis, Microcylloepus pusillus, Neoperla sp., Leuctra sp., Lumbriculis variegatus, Hydropsyche demora, and Boyeria vinosa were responsible for most of the dissimilarity between third and sixth order streams. Linear regression analysis identified one habitat variable (pH) that significantly influenced biotic condition scores.