Chironomid Size Distributions in Constructed and Natural Ponds: Responses to Land use and Water Quality
Abstract
Farm ponds in southeastern Minnesota are primarily constructed to prevent off-site soil erosion and to provide wildlife habitat in this predominantly agricultural landscape. Consequently, these ponds are subject to a variety of disturbances from agriculture, especially sedimentation and eutrophication. Natural ponds are rare and are located primarily at low elevations along tributaries to the Mississippi River. We examined chironomid richness, community structure and size-frequency distribution in response to a gradient of land use and water quality in 40 randomly selected ponds. Ponds were classified as natural or constructed; constructed ponds were further classified based on land use adjacent to the pond. Chironomid larvae and water quality were sampled 3 times in summer 2001. Chironomid generic richness significantly differed among pond type and community composition was strongly associated with adjacent land use. Size-frequency distributions were analyzed for the 10 most ubiquitous taxa: Polypedilum, Glyptotendipes, Chironomus, Tanytarsus, Procladius, Endochironomus, Ablabesmyia, Cricotopus, Dicrotendipes and Cladopelma. In general, slopes of normalized size-spectra for these taxa co-varied along the land use/water quality gradient. These results suggest that chironomid-body size may be a useful metric in biological assessments to evaluate the ecological integrity of constructed-pond ecosystems.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2005
- Bibcode:
- 2005AGUSMNB21C..05H
- Keywords:
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- 1815 Erosion and sedimentation;
- 1890 Wetlands;
- 4804 Benthic processes/benthos;
- 4845 Nutrients and nutrient cycling