9/25/2000

KUFM / KGPR

T. M. Power

Protecting Homes from Wildfire without Destroying Forests

One of the primary sources of emotional trauma associated with this summer’s wildfires was the threat that the fires would burn entire communities, obliterating people’s homes, their life’s work, and threatening their lives. A significant part of the overall fire control effort was aimed at protecting those homes and steering the fires away from areas of human habitation. It was the presence of uncontrollable wildfires in our backyards that made this fire season different from others in the past that actually burned more total acres.

A significant part of the emotional and political energy that is now going into proposals to reduce future fire dangers by physically removing fuels from our National Forests, by thinning and logging them, is generated by the vivid memories of fires sweeping down on our neighbors’ homes. Since most of us have no intention of abandoning our homes in the West’s forested mountains and valleys, it seems logical, even necessary, to do something to those forests so that they do not threaten us again. But, in fact, it is neither logical nor necessary. The problem that threatens our homes is not primarily tied to the forests but to our homes themselves.

Fire scientists have been studying the ways in which forest fires threaten homes for some time. They do this both through experiments that expose components of buildings to intensely burning forests as well as by studying how it was that homes that were destroyed by forest fires were actually ignited. The 200 homes destroyed in the Los Alamos fires this year, for instance, provided a case study that fire scientists have been carefully analyzing.

What these studies indicate is that it is rarely the intense radiant heat or flames from burning trees that lead homes to ignite and burn. If there is any significant break between dense forest and home, the structure will not be ignited by the heat and flames from the burning forest itself. Instead, the fire travels to the house by moving through the ground fuels in the area around the house or by wind-carried firebrands. In both cases, the fire will succeed in igniting the house only if highly flammable materials are available in the immediate vicinity of the home. A shake roof, rain gutters full of pine needles, stacks of split firewood, open windows, and lots of ground fuels are the types of things that allow wildfires to actually burn our homes. In the Los Alamos fires the pine trees in residential areas usually did not burn; it was not they that carried the fire. It was ground fire that usually ignited the homes. Those burning homes then ignited the immediately adjacent trees, leaving the rest of the forest crown untouched by fire. It was homes that were causing trees to burn, not trees causing homes to burn.

These facts raise serious questions about whether thinning and logging our forests can reduce the threat that wildfires pose to our homes and communities. Even if we thin and log all of our forested landscapes, some of them, as always, in dry, hot, windy years will burn. They may not burn as hot because the fuels available have been reduced. But it is not the heat of the fire that sets fire to our homes; it is the firebrands carried by the wind and the surface fuels. In an open, logged or thinned forest, the surface fuels will be dryer and wind speeds will be higher. The fire will still be carried to our home sites. If those home sites are not made fire resistant, the homes will still burn. The logging and thinning will have done nothing to prevent that. On the other hand, if there is no logging and thinning throughout the forest, but home sites have been treated to prevent both ground and crown fires from approaching the structure and to keep fire brands from finding ignitable fuels at the house, homes will not burn even if there is a very hot wildfire in the surrounding forests.

Given that sparks and firebrands can be carried a half-mile or more by the wind, if we do not focus our home protection efforts on the forested home sites instead of on the surrounding forest, we would have to remove all flammable vegetation for a mile or more around all homes. Well-watered, closely cropped lawns might fit that bill; but not trees, shrubbery or grazing or cropland. That would remove those lands from timber or almost any other production and eliminate the forested landscape that defines the region. I doubt that we are willing to pay that price to “fire-proof” our forests when there is a much less costly and less environmentally damaging solution: maintain our homes and home sites in a manner that protects them from the inevitable wildfires that are a natural part of our forested landscapes.

There may be other reasons for seeking to reduce fuel loads on extensive portions of our forests. But protecting homes is not one of them. It is crucial, if we care about our neighbors’ and our own homes, that we separate the issue of protecting homes from the issue of a major expansion of logging (under the guise of “thinning”) on our public lands. There is no logical, scientific, or public policy reason to link the two together. Those who insist on doing so are irrational fear mongers, pure and simple, who are pursuing their own self-interest at the expense of vulnerable homeowners.