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WASHINGTON, Nov. 15 (Xinhua) -- In the southern United States, the land's ability to soak up carbon from the atmosphere took a hit from Hurricane Katrina, which caused death and severe structural damage to approximately 320 million large trees, according to a new study released Thursday.
With the help of NASA satellite data, a team of biologists at Tulane University in New Orleans has estimated the losses inflicted by Katrina on Gulf Coast forest trees. Their study results will be published in the Nov. 16 edition of journal Science.
The August 2005 hurricane affected five million acres of forest across Mississippi, Louisiana and Alabama, with damage ranging from downed trees, snapped trunks and broken limbs to stripped leaves.
The disturbance weakened the role the forests play in storing carbon from the atmosphere, because the dead vegetation then decays, returning carbon to the atmosphere, and because the old vegetation is replaced by smaller, younger plants, said the researchers.
"The carbon that will be released as these trees decompose is enough to cancel out an entire year's worth of net gain by all U.S. forests. And this is only from a single storm," says Jeffrey Chambers, lead author of the study.
In their papers, the researchers speculate that if climate warming causes more extreme events and greater storm intensity, the corresponding damage to forest trees may contribute to atmospheric carbon dioxide levels, which seems to be a vicious circle. (Nov.16) |
