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Presented at the NABS Annual meeting, Athens, Georgia, 2003
in Community Ecology II
Landscape effects on stream water chemistry and benthic productivity
S.E. Fanta, C.L. Pederson, and R.U. Fischer. Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois 61920
With approximately sixty percent of Illinois' total acreage consisting of cropland, it is vital to gain further understanding of effects that such vast amounts of agriculture have on functioning of lotic systems. Our goal is to examine how changes in stream riparian zones and land use/land cover within watersheds determine the nature of abiotic stream environments and thereby impact structure and function of benthic communities. Twelve sites were sampled at two to four week intervals along the tributaries and mainstem of Hurricane Creek in Coles and Cumberland Counties, Illinois. A suite of physical and chemical variables was determined over the course of one calendar year. Data reduction by principal components analysis revealed site specific differences. In large part, these differences seem to be derived from variation in nutrient concentrations and stoichiometry. For example, average N:P ratios varied over three orders of magnitude at sites where we are conducting seasonal assessment of stream productivity. Analyses suggest that benthic algal productivity ultimately may be determined by land use and land cover within the watershed.
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