Principal Investigator Harold Hemond
Many streams in New England and elsewhere are acidic, particularly during spring runoff, when nitrate levels may be elevated. However it is not known whether the nitrate responsible for this stream acidification is the same as the nitrate deposited by the atmosphere or whether it is produced on the catchment by microbial activity (nitrification). We are using natural-abundance N-15 measurements at three contrasting New Hampshire watersheds in an effort to answer this question, and to better understand the cycling of nitrogen and its implications for environmental management. The three watersheds include the Bowl Research Natural Area, which experiences chronic nitrate loss; Hubbard Brook Experimental Forest, from which nitrate loss is episodic; and Cone Pond watershed, from which nitrate loss is nil. Early results suggest a major role for nitrification.