Nov. 5, 2014 – Even during summer dry spells, some isolated patches of soil in forested watersheds remain waterlogged.
These patches act as hot spots for microbes that remove nitrogen from groundwater and return it to the atmosphere, researchers from several institutions, including Virginia Tech, report in a leading scientific journal.
The discovery provides insight into the health of a forest. Nitrogen is an important nutrient for plant growth and productivity, but in streams, it can be a pollutant.
“The importance of these fragmented patches of saturated soil and their role in the fate of nitrogen in forested watersheds has been underappreciated until recently,” said Kevin McGuire, associate director of the Virginia Water Resources Research Center and associate professor of hydrology in the Department of Forest Resources and Environmental Conservation, based in Virginia Tech’s College of Natural Resources and Environment, co-author of a November article in the Proceedings of the National Academy of Sciences.
“We were able to determine the importance of denitrification in patches of shallow groundwater, which have largely been overlooked control points for nitrogen loss from temperate forested watersheds,” McGuire said. (continue reading story......)