Watershed simulation modeling demonstrated that roadside and riparian urban forest buffers can reduce nutrient loading in an urbanizing watershed. Forested roadside buffers reduced nitrogen loss by 6.59% and phosphorous loss by 6.57%. Riparian urban forest buffers were narrower, and therefore reduced nitrogen and phosphorous loss by 3.56% and 3.78%, respectively.
Matteo, Michelle, Timothy Randhir, and David Bloniarz. (2006). Watershed-scale impacts of forest buffers on water quality and runoff in urbanizing environment. Journal of Water Resources Planning and Management 132(3), 144-152.