U.S. scientists say higher levels of carbon dioxide predicted for later this century might help reduce damage to some trees caused by ice storms.
Researchers working at a Duke University outdoor test facility found commercially important 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 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, a Duke ecology professor. "My impressions were absolutely wrong. Instead of increasing the sensitivity to ice-storm damage, carbon dioxide decreased the sensitivity."
The scientists cautioned, however, they were not able to identify the actual mechanisms that helped to protect the trees grown under elevated carbon-dioxide conditions. "We just couldn't tease out anything obvious," McCarthy said.
The findings are reported in the Journal of Geophysical Research.
Copyright 2006 by United Press International
