Their findings are published in the September 23, 2004 edition of the leading science journal Nature and are featured in the journal's News and Views section.
Bret-Harte, Chapin, lead author Michelle Mack of the University of Florida, Gainesville, and colleagues set out to investigate whether the commonly held assumption that a warming climate will lead to bigger plants that can store more carbon and thereby reduce atmospheric carbon dioxide was indeed a silver lining in the global warming cloud that some people had hoped for.
"The broadest implication of this research is that climate warming could lead to a much greater release of carbon dioxide to the atmosphere and a greater positive feedback to further warming than we originally thought," Bret-Harte said.
In the experiment, conducted at IAB's Toolik Field Station, researchers measured the amount of carbon and nitrogen in plants and soils from plots of tundra that have been continually fertilized since 1980 a condition thought to simulate the increased nutrient availability expected as a result of a warmer climate. The plots are part of a 20-plus-year project by Terry Chapin of IAB, and Gus Shaver of The Ecosystems Center at the Marine Biological Laboratory in Massachusetts.
"One of the greatest values of IAB's Toolik Field Station is that it provides opportunities for long-term uninterrupted research in a pristine environment. We could never have gotten the results we did without such a long-term experiment," said Bret-Harte.
"The connection between fertilization and warming is that warmer temperatures should stimulate decomposition of dead plant materi
Contact: Marie Gilbert
University of Alaska Fairbanks