State, county grapple with historic tree die-off

By Joshua Emerson Smith, The San Diego Union-Tribune

As wildfires burn in Southern California, a debate is smoldering about what to do with millions of dead and dying trees -- which have been ravaged by drought and beetle species up and down the state.

Facing the biggest die-off since recordkeeping on the topic started about four decades ago, state officials have already started to cut down hundreds of thousands of dead trees near houses, roads, power lines and other sensitive areas.

"This is the largest coordinated effort to remove dead trees in California, as the tree mortality is unprecedented," said
Daniel Berlant, chief of public information for
Cal Fire, the agency leading the effort.

"We are in the middle of fire season, so these dead trees, especially around homes and other infrastructure, are a major concern for wildfires," he added.

What the state will do with the wood once it's cut down remains something of a question -- as does how far into the backcountry officials will continue chopping.

Emergency removal efforts have so far centered on populated areas of the Central Sierra, where pine trees affected by the native bark beetle have accounted for the lion's share of the state's recent tree mortality. However, a greatly expanded "hazard zone" has been identified by state officials that stretches much deeper into state and federal forests.

Agriculture Secretary
Tom Vilsack recently renewed a call for Congress to allocate money for firefighting to the Forest Service, which could help expand operations to cut down dead trees on federal lands. The agency spent 56 percent of its budget last year on fire management.

At the same time, efforts at the county and city levels to remove dead or dying trees in and around urban areas, as well as parks and forest areas, have sprouted up around the state. In the Tijuana River Valley in San Diego County, for example, officials are cutting down thousands of willows weakened by years of drought and destroyed seemingly overnight by the invasive shot hole borer beetle.

Some scientists have cautioned against too aggressively pruning back the forest. Patches of forest covered in fallen trees are an integral part of natural ecosystems, providing key species habitat and aiding in future woodland growth.

"In essence, this is one big statewide experiment," said
Matt Rahn, director of the environment institute and wildfire program at California State University San Marcos.

"What you're really dealing with is short-term risk versus long-term risk," he added. "Removal of trees right now might be a good thing, but what does that lead to in the next five, 10 or 20 years. Are you increasing the potential for fire risk? I think you are in some respects."

Since 2010, more than 66 million trees have died -- about 1.6 percent of the state's nearly 4 billion trees. The number is continuing to rise -- and at an accelerating pace. More than three-quarters of the devastation came in roughly the past 18 months.

While the state plans to remove only a fraction of those dead trees, the wood has already started to pile up, stoking fears that it could become a fire hazard itself.

Last fall, Gov.
Jerry Brown issued a state of emergency that called for cutting down the trees and diverting much of the material to power plants that use biomass. But it's not clear to what extent that shrinking industry will be able to consume all the chopped wood.

"One of the things that's been worked on for almost a year has been market development, and biomass energy has one of the biggest things," Berlant said. "The challenge is there are not that many biomass facilities available, and now there's more supply than there is demand.

"Right now there's no clear market for the wood, and so we have to continue to figure out are there new markets that maybe could use this wood in the future," he added.

At the same time, a newly created Tree Mortality Task Force has been working with dozens of local agencies and private stakeholders across the state to explore alternative ways to dispose of the material and even sell the lumber.

Because trees infested by the bark beetle are stained blue by a fungus carried by the insect, the value of a significant portion of the lumber has been somewhat diminished.

Traditional methods of disposing of unwanted dead trees such as mulching and chipping have also been ramped up, creating an excess of masticated material. Ideas for disposal have ranged from exporting it to foreign markets to using chipped wood in the Salton Sea for dust abatement.

Cal Fire recently spent several million dollars to purchase dozens of pieces of equipment including chippers, portable saw mills and, most notably, 10 air curtain burners.

Seen as a last result, the burners, also called fireboxes, are designed to reduce air pollution like soot that would otherwise be released into the atmosphere during a controlled burn or forest fire. Incinerating wood in such a devise still releases some smoke and greenhouse gasses into the atmosphere.

While officials are preparing to use the burners first in counties such as Kern, Fresno, Madera and Mariposa, plans are in motion to bring the incineration devices to other areas like Southern California.

"I know (San Diego County) is working desperately with other counties to raise the flag with the state, saying, 'Yes, you've got an enormous pine tree problem up north, but we have an enormous oak and sycamore and willow problem down here,'" said
James Bethke, an entomologist with the UC San Diego Cooperative Extension who works closely with the county parks department.

"In some places, they're grinding trees so they can use it as mulch," he added. "But when you have a two- or three-story-high pile of mulch, it's hard to move that somewhere to spread it in enough places."

The idea of using the burners and the associated greenhouse gases has frustrated environmental groups that have questioned the extent to which the dead trees actually pose a fire risk.

"If our concern is fire, then we need to be looking very specifically at what is a fire hazard," said
Brian Nowicki with the Center for Biological Diversity, a small but nationally prominent environmental organization based in Arizona. "Folks aren't looking at the science.

"So far, over the course of this year, the vast majority (of removed trees) have been along roads or communities," he added. "Those projects the center doesn't take issue with. The concerns are when you leave the roadway."

Recent studies have downplayed the link between increased wildfires and forests ravaged by beetles. Specifically, studies have found that dead and downed trees lose their most flammable properties within a year or two, and that harvesting large trees to reduce fire severity can actually be counterproductive.

"The fundamental claim that dead trees increase the potential for wildland fires to spread and burn intensely, that is dramatically contradicted by an overwhelming consensus of scientific studies," said
Chad Hanson, an ecologist with the Earth Island Institute.

"What the science is telling us is that fire is driven by weather," he added. "It's not driven by dead trees or even forest density so much."

Forest Service officials have said that at least two years of normal or above-average rainfall would be needed to improve the health of the state's most vulnerable trees.

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