and Chad Hanson
and Chad Hanson
This year, as in every previous year, fires are occurring in the forests of the Western United States. And, as in previous years, we read the predictable headlines about how many acres of forest were "destroyed" by wildland fires.
Some claim more logging is needed to "salvage" dead and dying trees and "rehabilitate" burned landscapes and nearly everyone complains about the smoke. But the central questions remain: Does fire harm forest ecosystems and what remedial actions are needed? And what should we do about all that smoke? Recent scientific evidence is providing answers that contradict many long-held assumptions.
There is far less fire in our forests today than there was historically. In the 19th century, prior to government fire suppression programs, the average annual area burned was eight to 10 times more than it is today. Over the past few decades, fires have increased somewhat, but still remain well below historic levels. Increasingly, forest managers are realizing that, despite a seemingly bottomless pit of fire-suppression government funds, we cannot and should not put all fires out.
Many of today's fires predominantly burn at low to moderate intensity as flames slowly creep along the forest floor, beneficially clearing out brush and leaving most trees with nothing more than fire scars. In other areas where most trees are killed by intense flames, scientists are making some of the most remarkable discoveries.
Far from being destroyed, these burned areas show extraordinary rejuvenation powers and unmatched ecological richness. Natural conifer regeneration is often rapid, with hundreds of seedlings per acre. Many of the largest, oldest conifers, because of their thick insulating bark, survive.
Even the threatened northern spotted owl makes use of severely burned forests, feasting on abundant woodrats in the forest regrowth and nesting in the remaining living and dead big trees. Many wildlife species such as woodpeckers depend primarily or exclusively on severely burned forests. They, in turn, perform vital checks and balances by feeding on insects that otherwise could become destructive pests.
So what should we do with forests before and after fires? Clearly, there are places where forests are more likely to burn uncharacteristically severely, primarily because of decades of fire suppression, some forms of logging and encroachment of homes into fire-sheds.
Tree farms are especially vulnerable, as small densely packed trees, lacking the thick insulating properties of older trees that were cut down, "torch" as fire races through them. To reduce such risks, forest managers can strategically target thinning of small trees, homeowners can remove flammable trees and brush, and developers can show some restraint about building in fire-sheds.
After fire, logging can actually affect a forest more than the fire itself by compacting and eroding life-giving soils, removing large trees that anchor fragile soils and shade new seedlings, taking big "snags" (fire-killed trees) that provide important habitat for wildlife and crushing conifer seedlings as logs are dragged uphill. Post-fire logging has even been shown to increase fire risks by leaving behind dense layers of logging slash as fuel for the next intense fire. Consequently, natural areas like old-growth forests and roadless areas should be allowed to recover on their own as they have for millennia.
Because we live in a fire-prone region, it is not a question of whether a forest will burn, but when and how. While no one likes smoke-choked skies, responsible fire management works with fire by carefully setting ground-burning fires during the spring and fall so that smoke and dense vegetation can be managed. It allows some fires to burn out in remote areas under safe conditions, because if we continue to suppress these fires, eventually they will burn out of control. And it puts other fires out that threaten lives and homes.
It is time we had a rational discussion on the proper role and management of wildland fire in our region; otherwise we will continue to confuse people about the inevitable and ecologically beneficial consequences of fire.
Dominick A. DellaSala, PhD (email@example.com) is chief scientist for the National Center for Conservation Science & Policy (www.nccsp.org), based in Ashland. Chad Hanson, Ph.D. (firstname.lastname@example.org) is director and fire ecologist for the John Muir Project (www.johnmuirproject.org), based in Cedar Ridge, Calif.