The recent rash of wildfires in Southern California will likely increase concern over long-term global warming. Research published in the Nov. 1 issue of the journal Nature concluded that wildfires in the boreal regions across northern Canada in 2003 were a major factor in higher carbon dioxide levels in that vast area, which is devoid of automobiles and other pollution sources such as factories.
Using a computer model to simulate the carbon balance of one million square kilometers of the Canadian forest over the past 60 years, scientists found that forest fires had the greatest direct impact on carbon dioxide emissions from the region. The fires resulted in a loss of the forest canopy and allowed more sunlight to reach the ground, in turn speeding decomposition and carbon dioxide emission from the soil.
"These results clearly demonstrate the direct control of disturbance, in this case wildfire, on the carbon balance of Canadian forests today," says Henry Gholz, program director in the National Science Foundation (NSF)'s division of environmental biology, which funded the research. "They also point toward a future where environmental conditions may be even more favorable for fires."