Editor’s Comments: Against the Grain

The western US has had more than its share of wildfires in the last few years. They’ve set records for sheer size and have caused unprecedented damage, virtually destroying entire towns. The aftereffects—erosion and landslides—are also expensive and deadly.

A new report suggests a large-scale plan to prevent fires in 35 high-risk zones in California, but there is little agreement as to whether its recommendations, which mainly consist of thinning out the forests, will actually help. Even some of the people responsible for the plan admit it might not do much to prevent the “megafires” the state has been experiencing, but they say it might help in other ways—giving people a little more time to evacuate, for example.

The debate on fire prevention was fueled, so to speak, late last year when President Trump criticized California’s management of its forests and suggested it might do well to follow the example of Finland, “a forest nation.” “They spend a lot of time on raking and cleaning and doing things and they don’t have any problem,” he said in November. Although it spurred a number of jokes on Twitter and mocking photos on Instagram of Finns with rakes, there was widespread support for his idea—let’s get rid of the dead trees and debris.

There is more than one reason we have so much dead wood in the forests; one of those, of course, is the drought, which has weakened and killed more than 100 million trees in California, as determined by aerial surveys from the US Forest Service. Another is that, in order to protect structures, we tend to extinguish fires as soon as they start—if we’re able to—so that fewer lightning-caused blazes are naturally allowed to burn their way through the built-up fuel. So a general cleanup seemed like a reasonable idea, and in March the California Department of Forestry and Fire Protection, known as CalFire, sent a 28-page report to the governor proposing to do exactly that.

The report has come under fire, however, from people who say the effort would be futile or might even make things worse. Removing trees and thinning the tree canopy could reduce shade, dry out the underlayer, and promote the growth of plants that are less fire resistant than the ones we’re getting rid of. Harold Zald, a professor at Humboldt State University, has studied many fires and says areas in California and Oregon that have been partially cleared through logging tend to have more intense fires than those that haven’t. “Having bigger trees and a more complex fuel structure, associated with natural regenerating forest, will have lower fire severity,” he said in a recent article, available at www.bit.ly/2HjbEE6.

CalFire is proposing what it calls “surgical thinning” rather than clear-cutting, which it says will reduce the rapid spread of fires. On the other hand, sparks from last year’s fires were able to travel as much as a mile. The 35 areas proposed for thinning, comprising some 94,000 acres, are not necessarily the spots where embers from a fast-moving fire will alight.

The logistics of such an operation are also in question. Hiring crews to thin the forest is expensive, and the work would need to be carefully coordinated so that branches and vegetation are hauled away as soon as they’re cut; leaving debris in place exacerbates the fire risk. Some experts are suggesting the money could be better spent on making individual homes and other structures more fire resistant—replacing roofing materials with more resistant ones, perhaps, or clearing wider swaths of vegetation away from buildings.