Year Established: 2011 Start Date: 2011-03-01 End Date: 2012-02-29
Total Federal Funds: $13,000 Total Non-Federal Funds: $26,001
Principal Investigators: Melody Bernot
Abstract: Stream ecosystems are influenced by multiple stressors associated with agricultural activities including increased nitrogen (N), herbicide, and fungicide from agricultural runoff. No study to date has assessed multi-stressor effects of agricultural activity on stream ecosystem N cycling or quantified how changes in stream ecosystem structure and function associated with increased N concentrations may be influenced by the confounding factors of increased herbicide and fungicide concentrations. The proposed study will address the fundamental question: How do herbicides and fungicides influence stream ecosystem N cycling? Basic biological research will be combined with microbiology to provide a more complete and integrative assessment of agricultural influence on stream ecosystems. The proposed research is novel in its multi-stressor approach. Our objective is to determine the influence of synergistic and antagonistic effects of multiple agricultural stressors on streams in the Upper White River Watershed in central Indiana, a tributary to the Wabash River. This objective will be met via two project components with related research questions: 1. Quantify spatial and temporal variability of multiple agricultural stressors: What factors control NO3-N, glyphosate, and chlorothalonil concentrations across central Indiana headwater streams and do these agricultural stressors co-vary? 2. Quantify synergistic and antagonistic effects of agricultural stressors in vitro: At what concentrations do NO3-N, glyphosate, and chlorothalonil alter ecosystem processes and does this concentration change when multiple stressors are present? These research activities will provide multiple lines of evidence describing the multi-stressor effects of agricultural activity in central Indiana streams.