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Ecoregional Influences on Watershed Land Cover, Water Quality, and in-Stream Biology
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| Abstract: | Omernik's ecoregions were developed to serve as a spatial framework for environmental monitoring and research. We examined the biology and chemistry in 35 headwater streams in the Little Miami River (LMR) of Ohio to determine whethEr there were real differences among three ecoregions. Land cover/land use features for the catchments and riparian corridors were evaluated along with variables related to geomorphology, hydrology, in-stream physical habitat, water chemistry, and fish, macroinvertebrate and periphyton assemblages. Although all of the watersheds in this study are dominated by row crop agriculture, differences in geomorphology, such as slope and soil types, lead to variations in land cover/land use such as relative differences in percent row crop or forest in both the catchments and the riparian corridors. Water quality variables, including nutrients (e.g., nutrients could be changed to total phosphorus, nitrate + nitrite nitrogen, ratio of dissolved organic to dissolved inorganic nitrogen, chloride, and sulfate) were significantly different among the ecoregions. In contrast, there were no significant differences among the ecoregions with respect to in-stream physical habitat measures. Likewise, we found no significant differences in biological indices (e.g., index of biotic integrity, and/or invertebrate community indices) or individual metrics for any taxonomic groups. Thus, the significant physical differences among ecoregions in the LMR did not necessarily translate into quantifiable in-stream biological differences. The absence of correlations between abiotic conditions and land cover/land use with biological assemblages among the ecoregions may be related to the historical degradation of in-stream physical habitat from human alterations. |
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| Citation: | Daniel, F. B., T. Flum, J. M. Lazorchak, and F. H. Mccormick. Ecoregional Influences on Watershed Land Cover, Water Quality, and in-Stream Biology. Presented at Society of Environmental Toxicology and Chemistry, Baltimore, MD, November 11-15, 2001. |
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| Contact: |
Linda Ransick - (513) 569-7395 or ransick.linda@epa.gov
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| Division: |
Ecological Exposure Research Division |
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| Branch: |
Immediate Office |
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| Product Type: |
Abstrct/Oral |
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| Presented: |
11/11/2001 |
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