Tree mortality epidemic in California forests keeps spreading

A task force set up by Gov. Jerry Brown is seeking solutions as drought, pests and other factors have killed 102 million trees in California forests since 2010.
Tim Hearden

Capital Press

Published on February 15, 2017 9:16AM

An aerial survey finds dead trees in the Los Podres National Forest in Central California. State and federal officials estimate that drought and pests have killed as many as 102 million trees in the Sierra Nevada since 2010.

Courtesy of U.S. Forest Service

An aerial survey finds dead trees in the Los Podres National Forest in Central California. State and federal officials estimate that drought and pests have killed as many as 102 million trees in the Sierra Nevada since 2010.


ANDERSON, Calif. — Drought, pests and overcrowded forests are contributing to a tree mortality epidemic in the Sierra Nevada that’s rapidly spreading, the leader of a state task force says.

Aerial surveys by the U.S. Forest Service last year found 36 million more dead trees, bringing the number of trees that have died in California forests since 2010 to more than 102 million, according to the state Tree Mortality Task Force.

The mortality epidemic has spread from the Fresno area to Placer County and is continuing to move north, said Gabe Schultz, the task force’s Redding-based chairman.

“It takes anywhere from a couple of months to a couple of weeks for (trees) to change,” Schultz said during a panel discussion Feb. 9 at the Sierra Cascade Logging Conference.

He showed several photos of dead conifers towering over houses, on which they could fall at any moment.

“This is a year-round life threat right now, not just a fire threat,” said Schultz, the state Department of Forestry and Fire Protection’s chief of resource management for the northern region.

As of this winter, Cal Fire and other agencies have removed more than 423,000 trees in 10 counties, inspected and cleared nearly 52,000 miles of roads and power lines, treated more than 26,000 acres and created roughly 1,300 acres of fuel breaks, according to a news release.

More than $10 million in state funds have been given out in grants for local projects to combat tree mortality, focusing on the removal of dead and dying trees around homes, the release explained. Another $6 million has been used for equipment to remove dead and dying trees in high-hazard zones.

The nearly five-year drought has been identified as the main cause of the die-offs, weakening trees and making them more susceptible to deadly attacks from pests.

The lack of water has left trees without the pitch necessary to prevent beetles from burrowing into the tree through the bark, leading to an infestation that overcomes the tree, University of California researchers have found.

Susie Kocher, a UC Cooperative Extension adviser, has written in a report that the best defense is to space trees widely enough to give them more access to resources and thinning the forest to reduce overcrowding.

State Assemblyman Brian Dahle, R-Bieber, agrees that a solution should be to allow more forest thinning.

“We’re going to see some huge fires” fueled by dead trees, he said. “There’s no way around it.”

But the sheer number of dead and dying trees in Central California forests could make their harvest and removal difficult.

For one thing, the number of trees greatly exceeds mills’ capacity to turn them into lumber, Sierra Pacific Industries corporate affairs and sustainability director Mark Pawlicki has said.

“The issue is where to put logs,” agreed Schultz, noting that sawmills are full and the number of biomass facilities is dwindling. He said the task force is considering obtaining more storage sites for logs, of which there are already a half-dozen.

However, a tree can only be turned into marketable lumber within three or four months of when it is harvested, he said. Otherwise, it has to be used for chips, firewood or other purposes, he said.

An October 2015 executive order by Gov. Jerry Brown created the Tree Mortality Task Force, which has representatives from more than 80 local, state and federal agencies, utilities and other organizations.

The group is redoubling its efforts as the epidemic of dead and dying trees keeps expanding, members say.

“This is going to be a continuous management problem for us,” Schultz said.



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