Fungus-killed oaks make Basin Complex fire hotter, harder to fight

Firefighters battling to protect Big Sur are working in forests riddled with many thousands of flammable dead oak trees, making the savage Basin Complex fire burn hotter and and travel faster, forest experts said Sunday.

Hundreds of thousands of oak trees in the area have been killed in recent years by a disease known as sudden oak death, producing fuel that allows flames to spread more quickly through redwoods and other evergreens, they said.

Although the massive oak die-off has swept through forests lining California's central and northern coasts, the Big Sur area is especially hard hit, said UC Davis plant pathology professor David Rizzo, an expert in the disease.

"It's reached its apex in Big Sur," Rizzo said Sunday. "The thing with Big Sur that's making it so bad is that's probably the worst place in the state for dead trees."

He estimates that 1 million dead oak trees can be found in a 200,000-acre sweep of Big Sur forest that he has studied for the last three years in a federally funded study of sudden oak death. That number was confirmed Sunday by retired U.S. Forest Service forester John Kelly, who conducted aerial surveys of dead trees in area forests and is now advising Basin Complex fire managers.

Sudden oak death has been traced to a fungus-like organism, Phytophthora ramorum, that can attack tanoaks, coast live oaks and California black oaks. Tanoaks can grow 60 to 80 feet tall and are major components of the coast redwood and mixed evergreen forests common on the Big Sur coast. Trees can take several years to die, and there is no known cure.

"You look in some of these canyons, and you'll see 70%, 80% of tanoaks are dead," said Rizzo, who expressed concern about the Palo Colorado Canyon area that fire crews have been defending.

U.S. Forest Service forest ecologist Lloyd Williams said Sunday that the dead oaks were most prevalent on the fire's western slope, representing about one-third of the 72,000-acre Basin Complex fire area.

"They're added fuel to the fire," said Williams, the botanist for Los Padres National Forest. "The intensity is much hotter. The fire burns hotter. It spreads faster." Since many of the dead oaks are still standing, he said "The fire can go up the tree and burning embers can spread."

The searing heat slows down crews.