Mitigation of nonpoint pollution by a riparian forest buffer in an agricultural watershed of the Mid-Atlantic Piedmont

350 210 Stroud Water Research Center

Newbold, J.D., S. Herbert, and B.W. Sweeney. 2009. Stroud Preserve Watersheds National Monitoring Project Final Report.

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A reforested riparian zone was established in an agricultural field in the Mid-Atlantic Piedmont in 1992. This study found that a 35-m wide 3-zone riparian forest buffer system removed 26% of the subsurface nitrate and 43% of the suspended sediments delivered from upslope. Total phosphorus was not removed by the buffer. The influence of tree growth on nitrate removal became apparent approximately ten years after planting. The grass filter strip between the forest and the cultivated field, contoured to disperse concentrated overland flow into the
reforested area, also functioned effectively to remove suspended sediments. It is important to recognize that this study did not address the indirect influences of riparian reforestation on water quality that arise from habitat improvements, including enhancement of habitat area within the stream (Sweeney et al. 2004). These improvements, in turn, enhance the ability of the stream to take up and process nutrients through processes such as in-stream denitrification that are critical to the protection of downstream ecosystems (Mulholland et al. 2008).


Funding was provided by the Pennsylvania Department of Environmental Protection through Section 319 of the Federal Clean Water Act administered by the US Environmental Protection Agency.

The project has received additional financial support for various periods since 1991 from the USDA Forest Service, the Pennsylvania State Bureau of Forestry, and the Chesapeake Bay Program. Technical assistance has been provided by the U.S.D.A. Forest Service, the Pennsylvania State Bureau of Forestry, and the USDA Natural Resource Conservation Service.