According to Safford, increased fuel on National Forest lands resulting from the long-term lack of fire is one of the principal drivers of recent increases in the size and severity of wildfires, trends which appear to be absent in the National Parks.
"The Rim Fire is not random occurrence. It's part of a trend in big fires, and a real wake up call," Scott Stephens agreed. Stephens, a professor at the University of California, Berkeley, authored a recent review on the characteristics and challenges of mega-fires with fellow fire specialists from Australia, Canada, Spain, and China, as well as the western U.S. in the March 2014 issue of Frontiers in Ecology and the Environment.
Large fires are a problem facing many of the world's temperate and boreal forests. As was the case with the Rim Fire, mega-fires are often driven by a combination of drought, heat, wind, fuel from fire suppression, budget cuts, and encroaching development, Stephens said.
These big fires are more expensive to contain and to recover from than the more frequent but less destructive fires that used to characterize the Sierra's mixed conifer forests, and they are dangerous for firefighters. They char enormous swaths of land, leaving large areas of up to 30,000 acres with no mature trees to seed a new generation.
"Most of the trees died in the Rim Fire. Not just the little guys. We're looking at multiple patches of high severity fire that are of thousands of acres in size," said Safford. "Where are the seeds going to come from? The landscape will be dominated by brush for a long time."
|Contact: Liza Lester|
Ecological Society of America