Breaking down California's fire ecology
What ecological conditions are contributing to the fires in California this year?
The Erskine Fire is being described as one of the most destructive in Kern County's history.
Two people, Brian and Gladys McKaig, died in the blaze, apparently from smoke inhalation. About 70 square miles have been blackened, and firefighting costs have reached more than $7 million.
The fire is now 45 percent contained, but what ecological conditions are contributing to California's fires? Brandon Collins is a research scientist with the U.S. Forest Service. He's also part of UC Berkeley's Fire Science Lab. He joined the show to explain.
What factors are contributing to this year's fire season?
"There's big concern for how things are lining up," Collins said. Though we did see a bit more rain this year compared to last year, there are ongoing effects of the drought to deal with. The millions of dead trees in California's forests, particularly in the Sierras, are also a factor.
The Erskine Fire is being fueled by brush, and not those dead trees. What's the difference?
Drought affects shrubs and trees differently. "What drought does in shrubs is it'll kill some limbs of the shrubs, so it'll be a little bit more dead material, but overall the shrub is stressed and has overall lower fuel moisture," he said. "So it means that shrubs can ignite more readily, given the current status of fuel moisture, and that's really driven by the drought. And that's a slightly different story on the forest side, which is exacerbated by this dead tree condition."
Where are dead trees the biggest fire threat?
Collins said an increase in dead trees is observed as you move south from Stanislaus River, and intensifies as you move into the southern Sierra National Forest. "What that does from a fire standpoint is that dead trees are basically already at a really dry level of fuel moisture, meaning that it will take very little for them to ignite. Whereas if you have a green tree, you have to basically drive off all the moisture in the needles before it can ignite. Now you have all these trees intermixed, sort of green and dead intermixed, so it basically brings up the hazard all over the forest."
What can be done now to lessen the risk of these fires?
Thinning the forests is the most obvious step, Collins said. "We know how to engineer these fuel treatments, if you will, but the problem is a lot of these issues related to wildlife, or other social issues. Sometimes people, frankly, just don't like seeing machinery in the woods cutting down any trees. But I think it's getting to a point now where we're going to have to start dealing with some of those issues for the sake of our forests into the future. We're losing big chunks of them in some of these fires, and it's going to take a long time to get them back."
Note: In an earlier version of this audio, we incorrectly stated there has been more than $7 million in damage from the Erskine Fire. That amount is the cost to fight the fire so far. We regret the error.