IRVINE, Calif., Feb. 7 (UPI) -- U.S. ecologists have found excess nitrogen in tropical forests boosts plant growth by an average of 20 percent.
University of California-Irvine scientists said their finding counters the belief that such forests wouldn't respond to nitrogen pollution.
The researchers said faster plant growth means the tropics will take in more carbon dioxide than previously thought, although long-term climate effects are unclear. During the next century, nitrogen pollution is expected to steadily rise, with the most dramatic increases in rapidly developing tropical regions such as India, South America, Africa and Southeast Asia.
Nitrogen fertilizer, applied to farmland to improve crop yield, also affects ecosystems downwind by seeping into runoff water and evaporating into the atmosphere, the researchers said, while industrial burning and forest clearing also pumps nitrogen into the air.
"We hope our results will improve global change forecasts," said David LeBauer, graduate student researcher of Earth system science at University of California-Irvine and lead author of the study.
The research that included Associate Professor Kathleen Treseder, appears in the February issue of the journal Ecology.
--
Copyright 2008 by United Press International.
All rights reserved.
--
