The daunting task of fire protection against bark beetle destruction
The number of trees killed by bark beetles and severe drought in California reached a new high in the latest count, but foresters say a few more wet and cold winters like last year’s would make a big difference toward restoring forest health.
An additional 27 million trees have died throughout California since November 2016, bringing the total number of dead trees to 129 million on 8.9 million acres, the Forest Service said this week in a joint statement with Cal Fire.
“The number of dead and dying trees has continued to rise, along with the risks to communities and firefighters if a wildfire breaks out in these areas,” said Randy Moore, regional forester for the Pacific Southwest Region. “It is apparent from our survey flights this year that California’s trees have not yet recovered from the drought and remain vulnerable to beetle attacks and increased wildfire threat.”
One good sign is the number of additional dead trees counted dropped 56 percent compared to last year’s count. Last winter’s rain and snow gave the forests a chance to recover, said Stephanie Gomes, Tree Mortality Team leader at the Forest Service.
It is apparent from our survey flights this year that California’s trees have not yet recovered from the drought.
Randy Moore, Pacific Southwest Region regional forester
“If we get a seriously good precipitation year, perhaps that number can go down in 2018,” she said.
Many dead trees are pines in the central and southern Sierra Nevada, the Forest Service said. Besides drought and beetles, other factors in tree mortality are forest density, climate change and air pollution.
The hardest-hit counties in a 10-county region are Tulare (25.2 million dead trees), Fresno (21.1 million) and Madera (14.3 million). The Tulare County Board of Supervisors voted unanimously Tuesday to continue its emergency proclamation, allowing it to seek federal funds for tree removal and other projects.
The Sierra National Forest north and east of Fresno has 760,000 acres where dead trees have been counted. That’s the most of the six national forests – El Dorado, Lake Tahoe Basin Management Unit, Sequoia, Sierra, Stanislaus and Tahoe – from north of Lake Tahoe to Lake Isabella east of Bakersfield.
The Sierra National Forest also has largest number of dead trees at nearly 32 million.
“On the Sierra, 55 to 60 percent of trees have died,” said Sierra National Forest supervisor Dean Gould.
With luck, Mother Nature will kill beetles, he said: “We need two or three years of really cold winters.”
If there’s a silver lining to the die-off, it’s that having fewer trees will result in a healthier forest over the long run, he said. Additionally, the Forest Service and public and private entities are taking action, Gould said.
The Forest Service and Cal Fire have been thinning forests around communities and using prescribed burns to reduce fire risk.
“It has brought a focus to the forest and forest health we have never had before,” Gould said. “It’s unfortunate it took a situation like this.”
On the Sierra (National Forest), 55 to 60 percent of trees have died.
Dean Gould, Sierra National Forest
To date, the Tree Mortality Task Force – an entity of 80 local, state and federal agencies, and utility companies including Southern California Edison and Pacific Gas and Electric – have felled 860,000 trees and are removing more. Of the felled trees, 480,000 were removed by the Forest Service, of which 258,787 trees were from the Sierra National Forest.
Some downed trees are being taken to seven biomass plants that produce electricity, the Forest Service said. Felled trees around campgrounds not removed are being stacked.
Some trees are being harvested for lumber, but beetle-killed trees quickly turn blue from a fungus that makes the wood hard to sell even though it’s still structurally sound, said Steve Brink, vice president of public resources for the California Forestry Association, a member of the task force. There are niche markets for blue-stained wood, he said.
Wood-boring insects also attack dead trees, which hurts their value.
Sawmills taking beetle-killed trees want them quickly before they are too low-value to process, he said. They mostly get them from private holdings because the approval process is faster, he said.
Sierra Forest Products in Terra Bella, the only sawmill still operating in the Fresno area, is getting beetle-killed trees from Southern California Edison property around Shaver Lake.
“There’s a short shelf life,” said general manager Kent Duysen. “A very high percentage of what we’re cutting is either fire-damaged or beetle kill.”