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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Disturbance Ecology IV
DICHOTOMOUS IMPACTS OF NUTRIENT ENRICHMENT AND PRODUCTIVITY IN COMMUNITIES OF VARYING DIVERSITY.
T. Romanuk. Department of Biology, McMaster University, Hamilton, Ontario, Canada L8S 4K1
The largest environmental impact of agricultural intensification is projected to be eutrophication of aquatic ecosystems. With global freshwater biodiversity declining at a faster rate than in even the most disturbed terrestrial ecosystems, understanding the effects of changing environmental conditions on relationships between biodiversity and the variability of community and population processes in freshwater ecosystems is of significant interest. Here I report on a freshwater microcosm experiment where I manipulated diversity and nutrient conditions. Conditions characteristic of eutrophication either masked the stabilizing effects of diversity on both community and ecosystem processes, or resulted in increased variability. These results suggest that nutrient enrichment may disassociate any stabilizing effects of diversity on variability, possibly due to a density effect and decreased asynchronicity in species responses in eutrophic systems.
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