During the summer of 1996, despite the meddling of thousands of firefighters and the expenditure of hundreds of millions of dollars in suppression efforts, fire blackened a record five million acres of forest and grasslands in the United States. Most media reports portrayed the fires as destructive, unnatural and yet another example of Nature out of control. From an ecological perspective, however, the summer of 1996 could be viewed as one of the best fires seasons in almost a decade.
Fire is one of the most significant ecological influences on a wide array of native ecosystems in North America. Its importance to everything from southern pine forests in Florida to boreal forests in Alaska is well-documented. Even ecosystems not typically thought of as "fire-dependent," such as the old-growth Douglas fir forests of the Pacific Northwest, often as not, got their start in the aftermath of a fire. Yet federal and state agencies continue to try to suppress and contain fires nearly everywhere they occur.
Although there may be a few instances where fire suppression on a local level is justified, a landscape-wide suppression policy is as misguided as the common practice of killing predators to "save" deer. Killing wolves or coyotes only delays mortality and the deer herd will ultimately succumb to disease, starvation or poor fawn survival. You don't "save" deer by killing predators anymore than you "save" a forest or grassland by suppressing fires. It is a narrow view of the ecosystem that sees fires as "destructive." Although fires kill trees, they support the forest ecosystem. It's a matter of seeing the forest for the trees.
Benefits of Fire
Fires perform a host of ecological "services" that are difficult, if not impossible, to replicate through human management and manipulation. Fires consume dead litter and debris, releasing nutrients for new plant and animal growth. Fires can thin a forest, freeing up resources such as water and soil nutrients for the survivors. Intense heat and smoke destroy some plant pathogens, creating better growing conditions. Fires create snags and other dead woody debris critical for providing cover or homes for many wildlife species from mammals to birds and insects.
Fires use different selective factors than humans or other animals in determining which plants and animals survive. For instance, in a grassland fires typically burn all plants equally, while grazing livestock select only the more palatable species. The result of livestock grazing is usually an increase in "non-desirable" species, while fire typically promotes a more balanced re-growth.
Despite the recognized benefits associated with fire, we continue to treat fires as if they "destroy" a forest. Fire fighters are often viewed as heroes, instead of like the old-time wolfers who pursued wolves to "save" the deer herd.
Salvage
One consequence of our relentless fire suppression policy is the idea that we need to "salvage" log the forest, either to remove dead and dying trees burned in fires or to "thin" the forest to remove fuels and thwart future large fires.
The idea that removal of burnt trees in the aftermath of a fire is harmless or even a beneficial activity is easily challenged. From an ecological perspective, dead trees are more important than live ones for a variety of the above-mentioned reasons--snags, wildlife habitat, nutrient storage and recycling. The assumption that dead trees are "wasted" is as antiquated as the idea that deer who are killed by predators, instead of hunters, are "wasted."
Secondly, once timber operations begin on a site, road construction, loss of wilderness qualities, and other associated impacts all contribute to the likelihood of future logging. Often, the time interval between logging rotations is insufficient to replace nutrients stripped from the site when trees are removed. Long-term loss of nutrients is a wide- spread occurrence, but it is not widely apparent because few places have gone through more than three or four logging rotations.
Thirdly, timber operations introduce a variety of unnatural impacts. These include soil disturbance and compression from the use of heavy equipment and road building, human access created by new roads, and the introduction of non-native plants, diseases and exotic wildlife that degrade ecosystem values.
Finally, nearly all salvage logging operations are money-losing affairs. Not only do we pay in the loss of ecological values, but we wind up paying for the environmental degradation that results.
Forest Health
The idea that forests need us to thin them for "forest health" is equally bankrupt. For one thing, although many forest stands are now experiencing heavy competition among individual trees for water, nutrients and light, the forest ecosystem is still healthy. A natural response to such competition is increased tree mortality from disease, insect attack and even fires. These are all natural thinning agents that help the ecosystem balance the flow of energy through living and non-living things. The idea that an increase in burned acreage, insect outbreak or disease requires a response and further manipulation from humans is suspect.
Furthermore, while it's true that in some ecosystems fire suppression has contributed to high fuel loading (build up of flammable materials), it doesn't necessarily follow that such forests require mechanical thinning to correct a perceived imbalance.
Management
First off, even if thinning were potentially a "solution," the amount of thinning necessary to make any kind of dent in fuel-loading across the West is immense. Literally hundreds of millions of acres would need thinning to markedly reduce the spread and intensity of fire on anything more than a local level. The financial cost of such thinning would be prohibitive, in part because most of the areas not already logged are among the highest, steepest and least-accessible sites--in other words, marginal sites for economical timber extraction. Furthermore, there are ecological costs to thinning because of the disturbance and disruption of natural processes associated with logging.
Secondly, all fire history analysis has a temporal and spatial component worth examining. The majority of all the areas burned, even in pre-suppression days, were burned by a few large fires. This was certainly true in 1996, when a handful of blazes contributed to the majority of acreage burned. Large blazes are controlled more by weather than by fuels. Conditions that contribute to huge fires are extreme drought coupled with high winds. Thinning forests will not appreciably change the occurrence of large fires because it can't change the climatic influences that create such blazes.
Thirdly, large fires should not be viewed as "abnormal." In many forest ecosystems, for example in the high-elevation lodgepole pine and fir forests in the West, "stand replacement" blazes are the norm. As a rule, these forests burned at widely spaced intervals of several hundred to a thousand years. Fire suppression has barely made any significant changes in fire frequency in these areas. Even the drier, low-elevation forests and grasslands of the West that on "average" experienced frequent, low- intensity burns occasionally experienced stand-replacement blazes.
Remember we are discussing "averages." The average fires prior to wide-spread fire suppression in the ponderosa pine forests, which stretch from east of the Cascades to New Mexico and Arizona, were frequent and low-intensity. But if viewed over a longer time interval, there were always exceptions to this generalization. Just as one can characterize a typical summer day in Montana as likely to be warm and sunny, I have, nevertheless, seen it snow occasionally even in the middle of July. Averages don't necessarily negate the occasional extreme event.
Historically speaking, if one looks back over a long enough time period, even low- elevation forests experienced occasional large stand-destroying blazes as a consequence of climatic variation. Over the short-term, frequent "cool" fires may dominate a site, but every few hundred to a thousand years, severe drought will affect an entire region resulting in intense, wide-spread fires. Though we may characterize such events as "extreme," one should not view such blazes as "abnormal" when considered within the proper temporal perspective.
Solutions
So what's the solution to our current forest health situation? I believe we need to re- evaluate our relationship with wildfires. With few exceptions, we should allow Nature to determine the appropriate fire intensity, acreage burned and timing of fire events. We should permit fires to burn unregulated over most of the natural landscape. In the few locations where such a policy is inappropriate--around human settlements, locally sensitive animal or plant communities, or other sites--fire defense, rather than suppression, should be the goal. Thinning trees or a prescribed-burn program to reduce fuels around a town, for example, is far less costly to implement than a policy of all-out suppression wherever fires occur.
We should also reduce conflicts with wildfire by zoning or otherwise restricting house construction in isolated, fire-prone locations. At the very least, the public should not spend tax dollars to provide fire protection in fire-prone areas. I have little sympathy for people who construct their homes on river floodplains, barrier islands along the coast or among western forests--all are gambling against what should only be viewed as natural events.
Finally, we need to challenge the assumption that logging, whether for salvage or otherwise, is "cost-free" or can be done in an ecologically sustainable manner. I suspect that any economically viable logging is unlikely to be ecologically viable.
Fires are as essential to most forest and grassland ecosystems as predators are to their prey. If we are concerned about preserving biodiversity we need to preserve the natural ecological processes that maintain that diversity. Fires are certainly a wide-spread and essential aspect of biodiversity preservation.