Wildfire Science

The articles below offer information on the evolving science of understanding and living with wildfires.

By Chad T. Hanson
January 31, 2018

The U.S. Forest Service recently proposed a sweeping effort to identify aspects of environmental analysis and public participation to be “reduced” or “eliminated” regarding commercial logging projects in our national forests. The Trump administration is attempting to spin this as an effort to promote “increased efficiency” for the expansion of forest “restoration,” but these are just euphemisms for more destructive logging.

Last summer, the Trump administration endorsed the Resilient Federal Forests Act, an extreme bill that would dramatically curtail environmental analysis and restrict public participation to increase logging of old forests and post-fire clear-cutting in our national forests. The bill passed the House of Representatives in the fall but stalled in the Senate. This new regulatory proposal is simply an effort to implement the same pro-logging agenda without going through Congress.

The proposal targets an astonishing “80 million acres of National Forest System land” for commercial logging — much of it comprising old-growth forests and remote roadless areas — based on the claim that logging and clear-cutting of these areas is needed, ostensibly to save them from fire and native bark beetles. Not so.

The overwhelming scientific consensus among U.S. forest and fire ecologists is that these natural processes are essential for the ecological health of our forests, including large events that create significant patches of dead trees, known as “snag forest habitat.” It may seem counterintuitive to some, but the science is telling us, loudly and clearly, that this unique forest habitat is comparable to old-growth forest in terms of native biodiversity and wildlife abundance. Many native species depend upon patches of dead trees, and the understory vegetation that grows in such patches, for food and homes. Forests naturally regenerate after fires, including the largest ones such as the 2013 Rim Fire in the Sierra Nevada, creating a complex and rich ecosystem.

The Trump administration’s claim that increased logging will curb forest fires is equally suspect. Science tells us that forests with the fewest environmental protections, and the most logging, actually burn more intensely, not less. This is because logging companies remove relatively non-combustible tree trunks, and leave behind flammable “slash debris” — kindling-like branches and twigs — and remove much of the forest canopy, which otherwise provides cooling shade.

The Forest Service has now begun promoting the notion that the 257,000-acre Rim Fire emitted about 12 million tons of CO2, based on a computer model that makes the mythological assumption that trees are essentially vaporized during fires. This is part of the “catastrophic wildfire” narrative that the Trump administration has weaponized to argue for rollbacks of environmental laws, and more commercial logging.

In fact, even in the most intensely burned patches, only about 2 percent of the total biomass of trees is actually consumed. Don’t be fooled. Trump’s proposal is nothing more than a thinly veiled attack on our national forests for the benefit of the logging industry.

Chad T. Hanson is director of the John Muir Project (www.johnmuirproject.org) and the author of “The Ecological Importance of Mixed-Severity Fires: Nature’s Phoenix” (Elsevier, 2015).

by Rick Coates

Fire season in California is normally a tense time.

Particularly in Sonoma County where so many of us live in and about the forest and depend upon the tourism that it generates. The recent large fires in Mendocino County and the ongoing drought has only heightened our fears.

One would think that CalFire would be looking for ways to decrease the likelihood and intensity of fires. One would expect that both the Governor and the Legislature, who must allocate taxpayer money to fire fighting, would be interested in ways to decrease the frequency and damage of fires. So I offer these suggestions in hope that they are listening.

It has been known for a long time that clearcutting, contrary to intuition, actually increases the likelihood of catastrophic fire. In 1970 a Stanford University study by Allan Cox and Davison Soper documented this effect. They found a high correlation between those areas that were clearcut and those areas that experienced major fires. The likelihood of fire in heavily cut areas was nearly 10 times greater than in uncut forests! In fact in 1969, a court of law confirmed that clearcutting increases fire danger.

Of course correlation is not causation, but it is difficult to see how forest fires might cause clearcuts. (“Selvage” logging of burned over forest was not included in the designation “clearcut” in the Stanford study.) After a little thought, it is far easier to see why clearcuts might cause fires.

Here is what the research shows:

A great deal of slash is left over from a clearcut which is where a majority of fires start and spread. In response to public pressure CalFire instituted meager regulation of slash but the industry fought them and the final regulations were pitifully inadequate.

After a clearcut, larger areas are opened up to grasses which dry out in the summer increasing flammability.

Clearcuts usually require extensive roadbuilding which produces even more slash and opens up formerly inaccessible areas to hikers, campers, fisherman, marijuana growers and the homeless with their cigarettes and campfires.