ASHEVILLE, NC--Hurricanes significantly lessen the capacity of US forests to sequester atmospheric carbon, according to a recent analysis by a USDA Forest Service researcher.

Global warming has been tied to increasing amounts of carbon dioxide released into the atmosphere from human activities ranging from clearing land to burning fossil fuels. Attention has been focused on US forests as possible sinks for carbon dioxide from various emissions. Estimates of the amount of carbon dioxide taken up by forests vary; predictions based on these estimates are an important factor in policy debates about global warming control.

In the March 2002 issue of the journal Environmental Pollution, Steven McNulty, USDA Forest Service Southern Global Change Program Leader, suggests that the effects of hurricanes must be taken into account in predicting the carbon storage capacity of US Forests along the southeastern seaboard.

At least one major hurricane hits the southeastern US coastline two out of every three years. Over 55 percent of the land in the southern U.S. is forested: timber damage from one hurricane can exceed $1 billion and significantly reduce carbon stored. A single hurricane can convert ten percent of the total annual carbon storage for the United States into dead and downed forest biomass, said McNulty. Hurricanes leave behind a lot of dead trees that decompose and return carbon to the atmosphere before it can be harvested.

McNulty analyzed hurricane damage data collected between 1900 and 1996 to address three issues related to carbon sequestration. First, he looked at how much carbon is transferred from living to dead carbon pools when trees are broken or uprooted. Second, he explored what happened to the downed trees whether they were salvage logged, burned, or consumed by insects. Finally, he examined the long-term impacts of hurricanes on forest regeneration and productivity.

McNulty found that even though hurricanes do
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Contact: Zo Hoyle
zhoyle@green.gov
828-257-4388
Southern Research Station - USDA Forest Service
22-Mar-2002