>This came from Roy Overton - >Subject: Environment News Service U.S. Ecosystems Altered by Nitrogen >Pollution >Date: Wed, 30 Jan 2002 12:01:00 -0600 >X-Mailer: Microsoft Outlook Express 5.00.2615.200 > > ><http://ln.doubleclick.net/jump/ly.ln/news_ens;h=news;prov=ens;pos=1;sz=468 >x60;tile=1;!category=adult;!category=financial;ord=1234567?>var lnb_S=1; >var lnb_I="VID=5005 > > <http://www.lycos.com>Lycos Home > <http://www.lycos.com/news/>News > > <http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../index.html>Envir > onment > > ><http://news.lycos.com/headlines/TopNews/default.asp>Top News Headlines > ><http://clubs.lycos.com/live/Annotation/BoardsCat.asp?Area=3&CG=lcrvhrh3on9 >133le004cfcdhuo>Environment News Message Board > ><http://my.lycos.com>Personalize Your News > ><http://dir.lycos.com/Society/Activism/Environment/>Environment Websites > ><http://www.lycos.com/news/>News Web Guide > ><http://clubs.lycos.com/live/ChatRooms/ChatSubCat.asp?CG=lcrvhrh3on9133le00 >4cfcdhuo&Area=1>Current Events Chat > ><http://news.lycos.com/headlines/Science/>Science News > ><http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../e-wire/>E-Wire > ><http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../ens/archives/arch >ive.html>Environment News Index > ><http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../ens/events/events >.html>Environment Events Calendar > ><http://ens-news.com/ens/jan2002/2002l-01-25-06.htmlens/youthdesk/youthdesk >welcome.html>Youth Environmental News Desk > ><http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../features/>ENS >Features > <http://www.ecomall.com>EcoMall > <http://www.scorecard.org>EDF Scorecard > <http://www.ecologyfund.com>Ecology Fund > >Environment<http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../aboute >ns.html> > >U.S. Ecosystems Altered by Nitrogen Pollution > >By Cat Lazaroff > >WASHINGTON, DC, January 25, 2002 (ENS) - Much of the nitrogen in >ecosystems throughout the United States comes not, as previously believed, >from natural sources, but from acid rain and agricultural fertilizers. A >study of ancient and unpolluted South American forests promises to upend >longstanding beliefs about ecosystems and the effects of pollution in the >Northern Hemisphere. > > > >Burning fossil fuels like coal produces nitrogen pollution (Photo courtesy >National Renewable Energy Lab) > > > > >Ecologists previously thought that nitrogen containing minerals, referred >to collectively as inorganic nitrogen, have always been the dominant >nutrient in forests worldwide. The study of South American forests, >however, showed a sharply different picture: complex, organic compounds >are the main form of nitrogen in unpolluted ecosystems. > >"It's one of those things where everybody's intuition that they've gotten >from studying the world is wrong," said Stephen Pacala, professor of >ecology and evolutionary biology at Princeton University. "It's still not >clear what the consequences are, but as a pattern it's completely >different. You know there have to be lots of implications." > >The study, published in the January 24 issue of the journal "Nature," >focused on nitrogen, a plant nutrient that plays a critical role in >maintaining everything from the health of local waterways to the global >climate. > >The authors argue that the ecosystems of South America, with their >preponderance of organic nitrogen, are a window into the past, showing >that U.S. ecosystems were very different before the industrial revolution. > > > >Agricultural runoff contains large amounts of nitrogen laden fertilizer >(Photo by Jack Dykinga, courtesy Agricultural Research Service) > > > > > >"We traveled in time by traveling to South America," said Lars Hedin, a >coauthor of the study and a professor of ecology and evolutionary biology >at Princeton University. > >Conditions in North America are different from those in South America for >two reasons, the researchers said. First, burning fossil fuels produces >great quantities of nitrogen and oxygen compounds, which wash out of the >air as acid rain. > >Second, during World War I the chemist Fritz Haber invented a process for >extracting nitrogen from the atmosphere for use in making explosives. The >Haber process allowed the mass production of fertilizers, which has fueled >a boom in agricultural productivity. > >In the remote areas of Chile and Argentina that the researchers studied, >there is no fertilizer use and almost no influx of fossil fuel emissions. > >The information they uncovered could have far reaching impacts in many >areas of ecology, from predicting the pace of global climate change to >understanding the consequences of acid rain and agricultural runoff. > >"I think it is potentially very important research," said Nico van Breemen >of the University of Wageningen in the Netherlands. "It raises points that >are fundamental for our understanding of very big global environmental >issues." > > > >Many forested areas in the United States are populated with young trees, >because the old growth forests have been logged (Photo courtesy ><http://www.americanlands.org>American Lands) > > > > >The findings raise questions about science's understanding of global >warming, which is partly caused by fossil fuel burning and increasing >levels of heat trapping carbon dioxide in the atmosphere. When trees grow >and mature they remove carbon dioxide from the air. > >The ability of trees to grow and absorb more carbon is intimately related >to the availability of nitrogen. > >"Nitrogen is a sort of master variable," said Steve Perakis, the paper's >lead author and a research scientist with the U.S. Geological Survey. "If >we don't get the fundamental elements of the nitrogen cycle right, we >can't answer many other ecological questions." > >The scientists spent five years preparing experiments in remote Chilean >temperate forests and another five years conducting detailed analyses of >water in those forests. They also conducted one time tests in a dozen >other remote areas in Chile and Argentina to prove that the preponderance >of organic nitrogen they observed was not unique to the site they were >studying. > >At the same time, they repeated their measurements in three U.S. virgin >forests, two in the Smokey Mountains and one in Pennsylvania. All of the >areas studied contained unlogged primary forests, in ecosystems that have >developed in place for 4,000 years to over 20,000 years. > > > >By contrast, many Chilean forests, like this stand of araucaria trees, are >far more ancient (Photo courtesy ><http://www.ancientforests.org/projects.html>Ancient Forests International) > > > > >The results suggest that in North America the impact of nitrogen pollution >from acid rain and agriculture may be more dramatic in years to come than >previously thought. > >North American forests are mostly young, recovering from past logging and >agricultural clearcutting. Young trees use nitrogen from the soil for >growth, serving as a buffer that lessens the impact of nitrogen pollution. > >As trees mature, they sequester less nitrogen from the environment. When >that happens, more inorganic nitrogen will be available to run off into >rivers and groundwater, changing conditions even more from their natural >state. > >Another interesting finding, said Perakis, was that the nitrogen cycle - >the way nitrogen compounds are exchanged between plants, soil, waterways >and the atmosphere - in South America is more uniform than it is in the >United States. > >"We found that even though there were some noticeable variations in South >America, they were pretty small compared to the variations caused by air >pollution," Perakis explained. "We live in a transient world, a world >that's changing because of many human activities, so many systems are >responding in unique ways." > > > > >Enter your email to receive the Environment News Service daily. > >Search ENS News and E-Wire Press Releases >Type Word or Exact Phrase, Hit Enter > ><mailto:[log in to unmask]>Email the Environment Editor > > > >© ><http://ens-news.com/ens/jan2002/2002l-01-25-06.html../../../aboutens.html> >Environment News Service (ENS)<http://www.hartcons.com/> 2001. All Rights >Reserved. >web site production by <http://www.hcstudios.com/>HC Studios > >Get your personalized Lycos news <http://my.lycos.com/>here. > > > » > <http://ens-news.com/ens/jan2002/2002l-01-25-06.htmljavascript:;>Lycos > Worldwide © <http://www.lycos.com/lycosinc/legal.html#copy>Copyright > 2001, Lycos, Inc. All Rights Reserved. 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