Fire strategy for our sick forests.

There is a rising tide of alarm over the condition of millions of acres of America's forests. In assessing forest health, the diagnosis in too many places is that today's forests are sick. Obviously, the reasons vary, and it is dangerous to generalize. But the problem is too widespread, and too serious, to ignore.

In the intermountain West, for example, large expanses of pine forest have become major risks for disastrous wildfires. Typically, the native forest was a pine savannah, characterized by large trees and an understory of scattered shrubs or grass. Periodic fires burned the grass along with fallen needles, limbs, and windthrown trees. Because the fuel loads were low and light and the pine bark was thick and fire-resistant, these fires caused little or no damage to the large trees. Early settlers removed the huge pines, or the old stands suffered a major fire or other natural event that did kill many of the big trees, and the area was left to regenerate naturally.

However, by the early 20th century, the emphasis in forest management was on controlling and preventing fires. The result is that the forests we see today are no longer naturally functioning ecosystems, but the unnatural result of decades of fire suppression. Stands of small, crowded trees were spared, and allowed to become stands of larger, more crowded trees. The increased competition for moisture and space kept growth slow and individual trees weak. Finally, drought cycles or a natural invasion of insects and disease occurred, and the forest was no longer able to resist. Today, as a result, vast areas of dead or dying trees become a tinderbox of fuel, waiting for a combination of dry weather and ignition.

Millions of acres of western forest are now in this condition. The question is no longer whether they will burn, but when and under what conditions. Because they have not been allowed to burn often and lightly, or because the excess fuels have not been removed through some other kind of silvicultural management, these forests are poised to explode in a Yellowstone-like inferno that can be physically impossible to control or divert, let alone extinguish. Instead of light, cool fires, intense super-hot burns often occur, causing soil damage that can alter watersheds and significantly slow forest recovery.

Many of these forests are heavily laced with homes, businesses, farms, private forests, and communities, where the danger of human and property loss is enormous.

The question is what to do now. If these forests are to become natural, healthy ecosystems in the future, it will almost certainly take human intervention. But there is little agreement on where, how, and when such actions should be taken, and many proposals are hugely controversial.

One option is to intentionally burn small areas, under conditions that are manageable, so that large fuel areas get broken up. But setting intentional fires carries its own set of risks, creates smoke, and can be fairly costly to carry out. Some people argue that we should let natural forces prevail--they claim that this is more ecologically sound than yet another human intervention.

Another option is to remove overcrowded, sick, dying, or dead trees through timber harvest where feasible. But public opposition to timber removal and its associated roads and other impacts is great. Many people decry the waste of valuable raw materials and job opportunities involved in not utilizing this wood while it has some economic value.

Still others recognize the enormous costs involved when a fire shifts into a high-gear disaster event. An ordinary firefight in the backcountry is one thing. But a big blowup with homes and communities involved is something else.

Now is the time for thorough public debate on these issues. Many forest owners, managers, and agencies are involved, and they must adopt a unified strategy. This is not a simple task. A complex array of laws, regulations, and plans limit what can be done. Scientific knowledge is far from complete on many of these ecosystems. The public is skeptical of many aspects of forestry, and both public and private budgets are stretched to breaking.

But the time for action is now, before catastrophe strikes. We cannot afford to wait until our science is absolutely certain, because that will never happen. "Natural" forces are unlikely to prevail, because these situations are hugely unnatural. If we get an event that combines the Yellowstone inferno and the 1991 Oakland, CA, disaster, there will be no time or public patience for reasonable discussion and cost-effective action. We'll be trapped into spending millions--perhaps billions--to replace values that need not have been lost. And we will mourn those who die and can never be replaced.