Event Title
Farm to Forest: A Multivariate Approach to Understanding Stream Habitat and Stressor Impacts on Coldwater Designation in a Lake Michigan Tributary
Description
Throughout the world, fertile riparian landscapes and aquatic headwaters are utilized for crop production and enhanced drainage, creating a patchy anthropogenic mosaic of land cover, while introducing a new norm in patterns of ecosystem stress, disturbance and freshwater system stability throughout a watershed. As watersheds of coldwater streams become more developed, this homogenous mosaic of agricultural land cover can have significant impacts on both local and downstream lotic thermal regimes and their associated biological dependents. Our objective was to examine how this agricultural land cover mosaic and the associated geomorphic, hydrologic, and landscape stressors affect the structure of downstream fish and macroinvertebrate communities in a Lake Michigan coastal coldwater stream of Muskegon County, MI, USA. Utilizing multivariate statistics, we found distinct relationships between the macroinvertebrate and fish communities of the three tributaries. These differences were attributed to habitat, geomorphic, and water quality stressors. Habitat unit distribution (riffle, run, glide, and pool) and large woody debris composition were strong determinants of these communities. Glide-pool dominant tributaries were characterized by scrapers and shredders while riffle-run reaches were strong drivers of EPT (Ephemeroptera, Plecoptera, and Trichoptera). Suspended sediment and streambank erodibility were more determinant along two tributaries than the others. Suspended sediment concentration and more-erodible streambank material were associated with glide-pool tributaries while streambank root density was greater in the riffle-run reaches. Variation in fish community assemblage was driven by thermal regimes and showed to be cold-stable to cold-moderate throughout the summer months. Results from this study are being used to manage water quality and stream habitat in the Little Flower Creek watershed and highlight the importance of evaluating several indicators of landscape stress to evaluate the upstream effects of agriculture on coldwater aquatic ecosystems.
Farm to Forest: A Multivariate Approach to Understanding Stream Habitat and Stressor Impacts on Coldwater Designation in a Lake Michigan Tributary
Throughout the world, fertile riparian landscapes and aquatic headwaters are utilized for crop production and enhanced drainage, creating a patchy anthropogenic mosaic of land cover, while introducing a new norm in patterns of ecosystem stress, disturbance and freshwater system stability throughout a watershed. As watersheds of coldwater streams become more developed, this homogenous mosaic of agricultural land cover can have significant impacts on both local and downstream lotic thermal regimes and their associated biological dependents. Our objective was to examine how this agricultural land cover mosaic and the associated geomorphic, hydrologic, and landscape stressors affect the structure of downstream fish and macroinvertebrate communities in a Lake Michigan coastal coldwater stream of Muskegon County, MI, USA. Utilizing multivariate statistics, we found distinct relationships between the macroinvertebrate and fish communities of the three tributaries. These differences were attributed to habitat, geomorphic, and water quality stressors. Habitat unit distribution (riffle, run, glide, and pool) and large woody debris composition were strong determinants of these communities. Glide-pool dominant tributaries were characterized by scrapers and shredders while riffle-run reaches were strong drivers of EPT (Ephemeroptera, Plecoptera, and Trichoptera). Suspended sediment and streambank erodibility were more determinant along two tributaries than the others. Suspended sediment concentration and more-erodible streambank material were associated with glide-pool tributaries while streambank root density was greater in the riffle-run reaches. Variation in fish community assemblage was driven by thermal regimes and showed to be cold-stable to cold-moderate throughout the summer months. Results from this study are being used to manage water quality and stream habitat in the Little Flower Creek watershed and highlight the importance of evaluating several indicators of landscape stress to evaluate the upstream effects of agriculture on coldwater aquatic ecosystems.