Herbaceous filter strips are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian zones for headwater streams has been documented, but the ecological impacts of herbaceous filter strips have not been evaluated. Our hypothesis was that establishment of herbaceous filter strips adjacent to channelized headwater streams will alter the riparian habitat and geomorphology, which will then cause changes in water chemistry, instream habitat, and fish communities. Beginning in 2006 we sampled riparian habitat, geomorphology, instream habitat, water chemistry, and fishes from three channelized streams without filter strips, three channelized streams with filter strips, and two unchannelized streams with forested riparian zones in central Ohio. Herbaceous filter strips were installed between 2003 and 2005 through the Conservation Reserve Enhancement Program.
Preliminary analysis of the first two years of data observed that channelized streams with filter strips had greater riparian widths than channelized streams without filter strips. No differences in geomorphology, instream habitat, water chemistry, and fish community variables occurred between streams with and without filter strips. These preliminary results suggest that within the first four years after installation herbaceous filter strips may only have a limited influence on channelized headwater streams in central Ohio.