219 Shredding macroinvertebrate responses to total phosphorus gradients in streams

Tuesday, May 19, 2009
Ambassador Ballroom
Clay Prater , Biology, University of Arkansas, Fayetteville, AR
Michelle A. Evans-White , Biological Sciences, University of Arkansas, Fayetteville, AR
Previous research examining patterns in macroinvertebrate richness found that shredder richness had a negative threshold relationship with total phosphorus (TP).  The focus of this study is to determine what which species and traits are more sensitive to water quality.  This question was addressed by examining benthic macroinvertebrate data collected by government agencies in Central Plains’ streams and compared to trends found in field collections of shredding macroinvertebrates across a forested land use gradient located in the Ozark Highlands.  Correlation analysis found significant reductions in occurrence for Acerpenna (r = -0.21377,p<.0001), Amphinemura (r = -0.27334, p<.0001), Cricotopus bicinctus (r = -0.25447, p<.0001), Cricotopus tremulus (r =-0.09538, p=0.056), Helichus lithophilus (r= -0.15258, P=0.0022), Lepidostoma (r = -0.0159, p=0.0014) Leuctra (r = -0.02716, p=0.0014), Nectopsyche (r = -0.09631, p=0.0537), Polypedilum (r = -0.10472, p= 0.0358), Prostoia (r = -0.152, p=0.0022), Pteronarcys pictetii (r = -0.14063, p=0.0047), Ptilostomis (r = -0.11026, p=0.0271), Tipula (r = -0.2248, p<.0001).  We also found increases in occurrence for Cricotopus (r =0.09722, p=0.0514), Helichus (r =0.14126, p=0.0045), Helophorus (r =0.1225, p=0.014), Nectopsyche candida (r =0.33829, p<.0001), Peltodytes (r =0.10787, p=0.0306), Polypedilum (r =0.23742, p<.0001).   This study should provide information about how nutrient gradients influence macroinvertebrate communities.