In contrast, much smaller vegetated strips can be used to significantly reduce sedimentation into lakes and streams. Below is a discussion of several important functions that vegetated riparian buffer zones serve. Included in the discussions are studies examining effective widths to achieve these goals. Protecting Water Quality One of the primary functions of a shoreland buffer zone is filtration of sediments from runoff waters. The addition of sediments to a river or lake can smother life on the bottom, such as fish eggs, clams, and insects that are a crucial component of the food web.
Sediments also decrease the water quality by blocking light needed for plant photosynthesis.
Contaminants such as phosphorous and agricultural chemicals can be carried by sediments into surface waters as well. Native vegetation within shoreland buffer zones act as natural filters to trap sediments contained in runoff waters before they reaches lakes and rivers. The change in pollutant export resulting from various levels of development intensity was studied by John Panuska of the Wisconsin Department of Natural Resources in the mid 1990's. His computer modeling work compared two 20,000 square foot areas. The first site was a typical maple-beech forest.