From late September through mid-November, professional burners set fire to hundreds of acres of diseased, dead and dying timber and volatile brush in a cautiously orchestrated program of prescribed burning.
"We're trying to create areas of modified fuels that will protect the rest of the park,"
said Gary Walter, a Department of Parks and Recreation resource ecologist and overseer
of the 11-year-old burning program. It's an ongoing process because treated areas usually
need to be burned again in about seven years to clean out regrowth.
Burning is tricky business. If not done correctly, a prescribed burn can quickly become an agent of destruction instead of prevention.
Prescribed burning is carried out after considerable testing and under optimal weather conditions. It carefully spares old-growth, such as 300-and 400-year-old pines, whose age has bestowed the advantages of height and thick bark that help them survive fires and insect infestations. The process targets areas of high probability for fires to start, generally next to roads and camping sites.
By November 1995, crews had burned about 70 acres at 2,000-acre D.L. Bliss State Park on the south shore, 90 acres at Sugar Pine Point State Park on the west shore, and six acres at Burton Creek State Park north of Tahoe City.
The fires cleared out much of the understory and thick, fuel-rich huckleberry oak and manzanita brush that feeds wildfires and carries flames aloft to destroy older trees that form the forest canopy. Burning also rids the forest of dead and dying trees that are victims of a bark beetle infestation aggravated by years of drought. At first, the beetles mainly bored into white fir, but now are killing the more hardy Jeffrey, ponderosa, and sugar pine.
"Last winter's rains and snows may have led people to think we were past the crisis, but we're not," Walter said. "We need several wet years to get the beetle infestation to slacken." Burning is the only practical way to cleanse the state parks of the beetles and the trees they have claimed. Aerial sprays exist, Walter said, but they're too costly, not wholly effective, and would never be acceptable to Lake Tahoe residents, who cherish the clean mountain air, already threatened by pollution from cars, and the water quality of the lake.
Besides reducing chances of catastrophic fire, burning releases nutrients that revitalize healthy trees and bares mineral soil that restores biodiversity, bringing forth vegetation from seeds that had lain dormant for a half-century.
"This process avoids loss of life and property, and you have a forest left afterward," Walter said.