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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Wetlands I
THE LARVAL ODONATE COMMUNITY AS AN INDICATOR OF IMPORTANT CONSTRUCTED WETLAND PARAMETERS.
L.L. Saunders1 and G.W. Fairchild2. 1LMTSD, 94 Cressman Road, Telford, PA 18969, 2Department of Biology, West Chester University, West Chester, PA 19383
In order for wetland mitigations to fulfill their purpose of replacing habitat they must support wetland fauna. One of the dominant invertebrate groups present in natural wetlands is the Odonata. Since the adults of this group are strong fliers they can be the first to reach newly created wetlands so they make excellent indicators for early wetland aquatic invertebrate communities. Four natural and five constructed wetlands in Southeast Pennsylvania were sampled for larval odonate biomass, abundance and species richness. Vegetation biomass and species richness, percent organic matter, water depth and the presence of fish were also determined for each wetland. Odonate biomass increased significantly with increasing vegetation and odonate abundance also tended to increase. Odonate species richness and abundance showed positive correlations with increasing vegetation species richness. Percent vegetation area, odonate abundance and species richness tended to decrease with increasing water depth within several of the wetlands. Fish presence had a significant negative effect on odonate biomass but not abundance or species richness. Overall odonate biomass was at its highest in shallow, well vegetated wetlands with no fish. These results would indicate that the parameters of water depth and vegetation are important in the design of wetland mitigation projects.
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