Influences of vegetated buffers on fish habitat in agricultural streams in michigan : implications for conservation

Agriculture provides food for humans and animals around the globe, however, it is also a stressor to ecosystems, including streams and the organisms they support. To reduce negative effects of agriculture on streams and ensure that it is practiced sustainably, conservation practices can help to address environmental concerns from agriculture. The goal of this research is to evaluate the utility of one conservation practice, vegetated stream buffers, in reducing effects of agriculture on stream fish habitats. In Chapter 1, we test for influences of forested buffers on fish habitat 30 streams draining heavily agricultural land in the Grand and Saginaw River basins, Michigan. Forested buffers have historically been promoted to reduce nutrient and sediment loading to streams, but they also contribute woody debris, maintain geomorphic units, and improve channel stability by preventing bank erosion, and our results showed that more forest in buffers was associated with decreased sedimentation and less channel erosion. Additionally, we also found that wetlands in buffers were associated with reduced streambed sediment. For Chapter 2, we extrapolated results from Chapter 1 to streams in the Grand, Saginaw, Kalamazoo, and St. Joseph River basins in Michigan to identify where implementation of vegetated buffers may improve fish habitat. This resulted in a series of maps showing locations of streams with limited fish habitat based on a lack of vegetation in their buffers along with maps showing locations of currently protected lands to identify areas that could benefit from additional conservation practices. Results from both studies will aid stakeholders by proving information to help them protect or implement vegetated buffers in heavily agricultural watersheds to improve fish habitat.