Durham, N.C. -- The increased levels of carbon dioxide in the atmosphere predicted for later this century may reduce the damage that future ice storms will cause to commercially important loblolly pine trees, according to a new study.

Researchers working at a Duke University outdoor test facility found that loblolly pines growing under carbon-dioxide levels mimicking those predicted for the year 2050 -- roughly one and a half times today's levels -- fared somewhat better during and after a major ice storm that hit the area than did loblollies growing under current concentrations of the gas.

The results came as a surprise, the researchers said.

"Before the storm, I was absolutely certain the pines would be more susceptible to ice damage under elevated concentrations of carbon dioxide," said Ram Oren, an ecology professor at Duke's Nicholas School of the Environment and Earth Sciences who directs the test site and participated in the study.

"My impressions were absolutely wrong," he said. "Instead of increasing the sensitivity to ice-storm damage, carbon dioxide decreased the sensitivity."

The researchers reported the findings August 8, 2006, in the Journal of Geophysical Research. The first author of the report is Heather McCarthy, a Nicholas School graduate student. The study was funded by the U.S. Department of Energy and the Forest Service.

Scientists predict that concentrations of carbon dioxide in the air will continue to rise as people continue to burn fossil fuels and clear land for agriculture, and that this rise will help drive global warming. Carbon dioxide is widely thought to play a major role in global warming because it traps solar heat in the atmosphere, much as the glass in a greenhouse traps heat.

At the Free-Air Carbon Dioxide Enrichment (FACE) experiment, located in the Duke Forest research reserve, researchers since 1994 have been studying how this predicted extra gas would a
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Contact: Monte Basgall
monte.basgall@duke.edu
919-681-8057
Duke University
15-Aug-2006