It’s dire news as California heads into the hot summer months and fire season: Federal officials announced Wednesday they had documented 26 million additional dead trees in California’s southern Sierra Nevada in just the last few months.
Those trees have been spotted in flyovers since October, and are located across 760,000 acres in six counties: Fresno, Kern, Madera, Mariposa, Tuolumne and Tulare. That’s in addition to another 40 million dead trees that forestry officials say they counted statewide between 2010 and October 2015, bringing the total number of blighted trees to a staggering 66 million.
While there are an estimated 3.9 billion trees in California, federal forestry officials said the large swaths of dying trees underscore a crisis in the nation’s forest management funding. Department of Agriculture Secretary Tom Vilsack called on Congress to bolster funding for the U.S. Forest Service to support management practices that would make the woods healthier and safer.
“Tree dies-offs of this magnitude are unprecedented and increase the risk of catastrophic wildfires that put property and lives at risk,” Vilsack said in a prepared statement. The Department of Agriculture is the parent agency of the Forest Service.
The drought has strained California’s forests, particularly stands of pine and fir. The problem is more pronounced in Southern and Central California south of the Eldorado National Forest, but foresters say they’ve seen signs of the blight spreading north. In the Tahoe Basin, for example, tree mortality doubled in 2015, according to ecologists. An estimated 35,000 dead trees were found in the basin last year.
The reason trees are dying is simple enough. In many drought-ravaged areas, there’s not been sufficient water for tree roots to siphon. Weakened needle-covered trees are unable to secrete the sticky resin required to fight off bark beetle infestations. Mild winters also don’t kill off as many of the bugs, which burrow beneath bark and into the tree’s soft innards on which their larvae feed.
Though some regions of the state – particularly in the north – received a fair amount of rain and snow last winter, more trees are likely to succumb in the years ahead because it takes time for drought-parched trees to recover, said Mark Schwartz, director of the John Muir Institute of the Environment at UC Davis.
“I suspect we’ll still see additional mortality no matter what next winter is like,” Schwartz said.
Experts say the problem is likely to become more common as California grows hotter and drier due to global climate change. Those trends are already becoming apparent in the huge fires that routinely scorch the Western landscape. The Forest Service says that on average, fire seasons are 78 days longer than they were in 1970 and the number of acres burned each year has doubled since 1980.
The Forest Service, which incurs 70 percent of national firefighting costs, is hamstrung in its efforts to restore the nation’s woods to a healthier state, Vilsack said. The explosion in firefighting costs has forced federal land managers to shift money that otherwise would be spent on forest restoration.
Last year, fire management accounted for 52 percent of the Forest Service’s budget, up from 16 percent in 1995. Federal officials said 2015 was the most expensive fire season in the Forest Service’s history, costing more than $2.6 billion.
Ecologists generally agree that forests across the West have grown unnaturally dense, leading to catastrophic fires that burn out of control. The Forest Service has signed off on a comprehensive national fire management strategy that includes prescribed burns as a critical component to thinning the woods. But how much commercial logging should also be employed is a source of passionate political dispute that’s played into the agency’s funding battle.
Forest Service officials for years have been asking that fire suppression be funded as a natural disaster rather than an ongoing agency operating expense. Last year, Western lawmakers from both parties supported legislation that would prevent the Forest Service from cannibalizing its budget to fight wildfires, but disagreement over how much logging should be allowed in national forests caused a deal to collapse.
Vilsack said Wednesday that California’s dead trees ought to pressure Congress to act one way or the other.
“Forcing the Forest Service to pay for massive wildfire disasters out of its pre-existing fixed budget, instead of from an emergency fund like all other natural disasters, means there is not enough money left to do the very work that would help restore these high mortality areas,” Vilsack said.
Schwartz, the UC Davis professor, said the problems and risks multiply year to year, as the Forest Service struggles to replant trees in the areas already scorched by fire.
“Something has to give,” Schwartz said. “You can’t have a Forest Service that is really a firefighting service and does nothing else.”
California tree species
The drought has strained California forests, particularly its stands of pine and fir. Here is a breakdown of the state’s tree population, by species.
No. of trees
Ponderosa and Jeffrey pines
Western white pine
Engelmann and other spruces
Western red cedar
Other western softwoods
Cottonwood and aspen
Other western hardwoods
Source: U.S. Forest Service