Wednesday, May 28, 2008 - 2:30 PM
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Macroinvertebrate community attributes and related environmental features in permanent and semi-permanent prairie pothole wetlands in north-central Iowa

Valerie A. Hentges and Timothy W. Stewart. Department of Natural Resource Ecology and Management, Iowa State University, 339 Science II, Ames, IA 50011

Wetlands perform important ecological functions, including filtering pollutants and providing wildlife habitat and food resources. Functions are influenced and reflected by macroinvertebrate community attributes, including abundance, taxonomic composition, and diversity. We quantified macroinvertebrate community attributes in 18 semi-permanent and permanent prairie pothole wetlands in north-central Iowa and related community attributes to environmental features. In the summer of 2007, macroinvertebrates inhabiting the water column, water surface, and benthic habitat were sampled at 40-50 cm depths using a stovepipe sampler and fine-mesh net. Macroinvertebrate biomass, densities, taxa richness, and proportional abundance of ecologically-sensitive taxa were determined. We also quantified coarse particulate organic matter (living and nonliving plant material) abundance, pH, temperature, tree canopy cover, turbidity, concentrations of dissolved oxygen, nitrogen, and phosphorus, and fish and salamander presence. Regression analyses were used to identify significant relationships between macroinvertebrate community attributes and environmental features. Preliminary results show a negative relationship (Adj. R² = 0.39, p = 0.003) between turbidity and taxa richness of large-bodied macroinvertebrates (individuals ≥ 2 cm long; e.g., dragonflies, damselflies, leeches, crayfish, snails). Identification of this and similar relationships along with their causes will assist in developing management strategies to maximize functionality of Midwest USA wetlands.


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