3/17/2010 - 1:51:13 PM
NCAR: Burns reduce carbon footprint
By Business Report Staff
BOULDER - The use of prescribed burns to manage Western forests may help the United States reduce its carbon footprint, according to a study conducted by the National Center for Atmospheric Research in Boulder.
The study finds that such burns, often used by forest managers to reduce underbrush and protect bigger trees, release substantially less carbon dioxide emissions than wildfires of the same size.
"It appears that prescribed burns can be an important piece of a climate change strategy," said Christine Wiedinmyer, a scientist with NCAR and lead author of the study. "If we reintroduce fires into our ecosystems, we may be able to protect larger trees and significantly reduce the amount of carbon released into the atmosphere by major wildfires."
The study is being published this week in Environmental Science and Technology. It was funded by the National Science Foundation.
Drawing on satellite observations and computer models of emissions, researchers concluded that widespread prescribed burns can reduce fire emissions of carbon dioxide in the West by an average of 18 percent to 25 percent, and by as much as 60 percent in certain forest systems.
Wildfires often destroy large trees that store significant amounts of carbon. Prescribed fires are designed to burn underbrush and small trees, which store less carbon. By clearing out the underbrush, these controlled burns reduce the chances of subsequent high-severity wildfires - protecting large trees and keeping more carbon locked up in the forest.
"When fire comes more frequently, it's less severe and causes lower tree mortality," said Matthew Hurteau of Northern Arizona University, the study's co-author. "Fire protects trees by clearing out the fuel that builds up in the forest."
Forests have emerged as important factors in climate change. Trees store, or sequester, significant amounts of carbon, helping offset the large amounts of carbon dioxide emitted by factories, motor vehicles and other sources. When trees burn down or die, much of that carbon is returned to the atmosphere. It can take decades for forest regrowth to sequester the amount of carbon emitted in a single fire, according to the study.
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