You are here:
VERTICAL, LONGITUDINAL, AND TEMPORAL VARIATION IN THE MACROBENTHOS OF AN APPALACHIAN HEADWATER STREAM SYSTEM
Citation:
Angradi, T., R. D. Hood, AND D. Tarter. VERTICAL, LONGITUDINAL, AND TEMPORAL VARIATION IN THE MACROBENTHOS OF AN APPALACHIAN HEADWATER STREAM SYSTEM. AMERICAN MIDLAND NATURALIST. University of Notre Dame, Notre Dame, IN, 146(2):223-242, (2001).
Description:
We examined vertical, longitudinal, and season variation in the abundance, diversity, variability, and assemblage composition of the epibenthic and hyporheic macrobenthos at Elklick Run, a first-through fourth-order stream continuum in the central Appalachian Mountains in West Virginia, U.S.A. We sampled the macrobenthos down to 30 cm below the stream bed using natural-substratum-filled baskets. We quantified environmental factors including interstitial organic matter, fine sediment, water velocity and dissolved oxygen. Abundance, taxa richness, and the relative abundance of streamlined/flattened taxa decreased with depth into the substratum. Interactions between depth into the substratum and site and between depth and season were caused by a winter spate which affected the benthos in the upper layer of the hyporheic habitat (0-10 cm) but only at downstream sites. Very few taxa increased in absolute abundance with depth into the substratum or were unique to hyporheic habitat. Abundance and taxa richness varied more with depth into the substratum than with site or with season. Among-site and among-depth strata variation in assemblage structure were nested within seasonal variation, however. The coefficient of variation in abundance, taxa richness, and assemblage composition decreased with increasing stream order suggesting decreased spatial variability in interstitial habitat suitability. Abundance of the macrobenthos was positively correlated with interstitial flow, especially at upstream sites in summer when water temperature was high and interstitial dissolved oxygen was low. Overall, the Elklick Run riffle assemblage was more hyporheic-adapted than epibenthic-adapted.