Minneapoli/St. Paul --The world's land plants will probably not be able to absorb as great a share of the rising atmospheric carbon dioxide as some models have predicted, according to a new study led by Peter B. Reich, professor in the department of forest resources at the University of Minnesota. The work showed that limitations on the availability of nitrogen, a necessary nutrient, will likely translate to limitations on the ability of plants to absorb extra carbon dioxide (CO2). Given that a large proportion of the world's soils are nitrogen-limited, the study implies that the rate of increase in atmospheric CO2 levels could turn sharply upward as nitrogen-limited plants lose their ability to take advantage of the extra CO2 "food." Since rising atmospheric CO2 levels are the largest cause of global "greenhouse" warming, this raises the possibility of accelerated global climate change. The work will be published in the April 13, 2006, issue of Nature.
The six-year study is the first long-term examination of how soil nitrogen affects the abilities of long-lived plants in realistic "natural" open-air ecosystems to increase their size by absorbing extra CO2. Only two other long-term experiments in the world are asking similar questions.
As fossil fuel burning continues and increases, more CO2 is pumped into the atmosphere. Some reports, including the Intergovernmental Panel on Climate Change's "Climate Change 2001: The Scientific Basis," predict that terrestrial plants will be a considerable "sink" for excess CO2. But the researchers, including University of Minnesota scientists Sarah Hobbie, David Tilman and Jared Trost, conclude that the sink may not be as big as projected because the effects of low nitrogen on plants' ability to increase their growth wasn't taken into account.
"After a few years, there was only a very modest increase in growth due to CO2 unless extra nitrogen was added," Reich said. "This lack of CO2 growth stimulation wPage: 1 2 3 Related biology news :1
Contact: Deane Morrison
University of Minnesota
. Plants recognize their siblings, biologists discover2
. Plants that produce more vitamin C may result from UCLA-Dartmouth discovery3
. Plants tag insect herbivores with an alarm4
. Plants with male and bisexual flowers on the same plant are better mothers5
. Plants do not emit methane6
. Plants management of nutrient suggests environmental remedies7
. Plants point the way to coping with climate change8
. Plants, plasmids and possibilities -- Methods permit functional gene studies in plants9
. Plants give up answers in the war on bacteria10
. Plants tell caterpillars when its safe to forage11
. Plants role in global warming re-examined in ORNL Science paper