Environment - Nature's healing hand
Streamside vegetation can help reduce the impact of increasing levels of nitrogen in rainfall that can cause algal blooms and degradation of drinking water. Combining computer simulations and data from 12 years of field measurements, Patrick Mulholland of Oak Ridge National Laboratory found that biological organisms in the stream removed about one-fourth of the nitrogen and phosphorus entering the stream from the watershed. The immediate benefit is reduced concentrations of these nutrients reaching downstream lakes, estuaries and the ocean. Removal of nitrogen and phosphorus from stream water was highly seasonal and responsive to forest processes, with greatest removal occurring in the autumn and early spring. "This research demonstrates the strong effects of streamside vegetation and points to the important role of streams in preventing high nutrient exports and the eutrophication of downstream aquatic ecosystems," said Mulholland, whose findings will be published in Biogeochemistry. The research was performed on the Walker Branch Watershed of the Department of Energy's Oak Ridge National Environmental Research Park. Funding was provided by DOE's Office of Biological and Environmental Research.
November 10, 2004