Flanked to the west by the Cleveland National Forest, Lake Elsinore and Wildomar have been threatened by wildfires throughout history.
But research out this week provides new thinking on how to prevent forest fires: Mountain forests should be managed according to local fire history and ecology - not with whole-scale fire suppression or "one-size-fits-all" plans, according to a study cited Tuesday by the U.S. Geological Survey.
While the local Cleveland National Forest is comprised mostly of chaparral, conifers are prevalent at peak elevations.
"In dry temperate forests, such as mixed-conifer forests in California and ponderosa pine forests in Arizona, the long-term result is that trees are getting killed by fires faster than they can grow back," Matthew Hurteau, an assistant professor at the Northern Arizona University School of Earth Sciences and Environmental Sustainability, told the USGS.
"And, since burning trees release carbon and growing trees store carbon, the result is that some of our forests are becoming a net source of carbon emissions," Hurteau said.
In their study published this month in BioScience magazine, Hurteau and Matthew Brooks of the USGS studied forest ecology and fire treatment research in California and Arizona.
Although decades of fire suppression have reduced fire frequency, they have allowed forest fuels to build up in some forests to the point where fires are now more severe and kill more trees, according to Hurteau and Brooks.
Catastrophic fires in 2003, 2006, 2007, 2008 and 2009 destroyed thousands of homes in Southern California. In October 2006 five U.S. Forest Service firefighters died in the arson-set Esperanza Fire that started in Cabazon.
Forest managers in California already have to balance habitat protection, timber production, carbon sequestration and community risk to wildfires, according to the USGS.
Hurteau and Brooks suggested in their study several ecology-based fire management practices to help dry temperate forests return to more natural fire regimes -- steps that are already being practiced in and around some fire-endangered communities in the San Bernardino National Forest.
Throughout Southern California, local, county and federal forestry efforts in recent years have included manual and mechanical thinning or removing small to medium trees -- because they act as "ladder fuels" for fires to spread to tree tops, where flames can spread to surrounding trees and increase in intensity.
Some communities are safer from catastrophic fires thanks in part to tree thinning, but the costs involved mean there are still thousands of dead trees in the San Gorgonio and the local San Jacinto mountains.
Hurteau and Brooks in their study recommend other practices to thin ladder fuels such as allowing low- to moderate-severity wildfires to spread or using prescribed fires.
"By managing a forest according to the natural fire regime it is adapted to, it stands a better chance of long-term survival," said Brooks, who is based at the Yosemite Field Station of the USGS Western Ecological Research Center.
"A dry temperate forest returned to its fire regime of regular burns is a forest that stores more carbon, provides more habitat and timber, and isn’t prone to wide-spreading, tree-killing fires."
Funding for the study came from the Forest Service, the Bureau of Land Management, the USGS and the National Park Service.