The scientists' goal is to get an early look at how ever-increasing CO2 levels emanating from industrial smokestacks, vehicle exhausts and forest-clearing -- the same human causes being blamed for forecasted global warming -- could change future ecosystems.
Similar past experiments in greenhouses and open-top growth chambers have hinted that higher carbon dioxide levels could increase growth levels in some plant species. But until experiments like FACTS-1, scientists have had no way to evaluate the effects of high-CO2 in a "real-world" setting.
In 1995, researchers from Brookhaven and Duke had reported elevated photosynthetic activity at an initial Duke Forest tower ring erected to test the reliability of maintaining 1 1/2 times higher than current levels of the gas in the open air. But, standing alone, with no other test sites or matched controls to compare their results to, that initial Free-Air Carbon Dioxide Enrichment (FACE) experiment was not considered "fully replicated," a gold standard for research.
The fully replicated FACTS-1 experiment began in 1997 after additional funding from the U.S. Department of Energy allowed construction of six more rings. Project organizers at Duke and Brookhaven hope it can continue operation for at least a decade, allowing scientists time to gauge longer range impacts on a complex ecosystem.
A total of eight different scientific papers on FACTS-1's first year results were scheduled for the current ESA meeting.
Delivering a multi-authored analysis of overall tree growth, Shawna
Naidu, a post doctoral researcher at Illinois, reported that the 12 percent
increases at the active FACTS-1 sites occurred in the face of low soil fertility
and perio
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Contact: Monte Basgall
Monte@dukenews.duke.edu
919-681-8057
Duke University Medical Center
4-Aug-1998