Replies from the fire gods.

In the great debates over how to manage our public domain, the 1988 Yellowstone fires provided something for everyone. We have seen them used to support every imaginable management scenario for the national parks, as well as a few that seem unimaginable.

Sagebrush rebels announced that the fires prove the entire Greater Yellowstone Area (GYA) should be transferred to private ownership. Proponents of single-direction management of the GYA-composed of two national parks, six national forests, and a variety of other lands- assert that the fires prove this 12-million-acre area should be even more firmly controlled by some overarching federal body. Wilderness purists find in the fires proof that the only "disaster" associated with the fires was cultural-the loss of buildings and commercial revenueand that we should turn the park entirely back to nature. These and many other positions have been put forward. Most of them claim to have science on their side.

Dr. Thomas Bonnicksen's recent comments on fire policy in AMERICAN FORESTS provide an excellent example of how this process of dialogue becomes derailed. His is only one of hundreds of voices in the current debates, but like several of his fellow commentators, he has regrettably set himself up as an omniscient observer rather than as someone engaged in earnest inquiry.

He tells us that he "investigated the effects of the Yellowstone wildfires for members of Congress." Actually, Dr. Bonnicksen spent three days here at the invitation of one Congressman, and reveals throughout his essay an appalling ignorance of Yellowstone fire ecology.

He says, for example, that the fires of 1988 "were not a natural event." He seems to change his mind frequently about what "natural" is, but his statement is not the view of the scientific authorities.

Dr. William Romme of Fort Lewis College and Dr. Don Despain of the National Park Service have put more than 25 years into studying the longterm fire history of Yellowstone. Their judgment, published in such respected journals as BioScience and Scientific American, is that the fires of 1988, despite having a variety of natural and human causes, very nearly replicated similar natural events that have occurred every 200 to 400 years in the past in this region.

This judgment was supported by the Greater Yellowstone Postfire Ecological Assessment Workshop, a blueribbon panel of 13 prominent non-NPS authorities chaired by Dr. Norman Christensen of Duke University. This panel's findings, released last summer, are the kind of penetrating, critical analysis, firmly based in science, that the fire dialogues require.

Dr. Bonnicksen believes that the NPS is managing the parks on some bizarre emotional or spiritual basis rather than on a sound scientific basis. In fact, the science upon which we base our management is excellent, copious, and teaching us new things at an exciting rate. It appears that the only real problem with our science is that it disproves Dr. Bonnicksen's viewpoint.

Consider his discussion of the scientific work of Dr. James Brown, U.S. Forest Service fire specialist who recently analyzed the possibility of using controlled burns in Yellowstone to prevent large fires. Dr. Bonnicksen quotes a recent paper by Dr. Brown as saying that planned ignitions are "necessary to deal with fuels and topography that have high potential for fire to escape established boundaries." Then Dr. Bonnicksen uses that statement to prove" that the acreage burned could have been substantially reduced by prescribed burning in the years before 1988.

In fact, Dr. Brown reached exactly the opposite conclusion. Dr. Brown believes-and demonstrates clearly in his paper-that prescribed burning might have helped protect villages, but that even if the NPS had embarked on aggressive prescribed burning in 1972, at the beginning of the Yellowstone natural fire program, "the amount of area burned would not have changed significantly."

This sort of misrepresentation is common in Dr. Bonnicksen's article. He has set up a series of strawmencaricatures of the actual federal positions on fire management-for the convenience of his criticisms. This does nothing to advance meaningful dialogue. The same is true, by the way, of his casual assertions about park ecology. If he was up on his science, for example, he would know that Yellowstone's grizzly bear population is not declining; it's doing so well that pressure is growing to remove the grizzly from the threatened and endangered species list.

It is necessary to stand some distance from the fire dialogues to appreciate what they are about. They are largely about differing views of our relationship with nature. Again, there is a full spectrum of perspectives. On one extreme are the people who would manage natural areas such as parks and wilderness areas as gardens what Dr. Bonnicksen views as "safe and attractive forests"-where humans are always in control. There are others for whom nature has no higher value than its very freedom, the sort of wilderness promoted by Robert Marshall and Aldo Leopold, which has its highest value when it is least controlled.

Dr. Bonnicksen's position in these dialogues falls under the "intensive husbandry" heading, and he understates the situation when he says it is unpopular among some conservation groups. It is very unpopular among many conservationists, who regularly criticize the NPS for any inclination to manipulate park settings for the convenience of humans.

For example, many conservationists would object that when Dr. Bonnicksen calls for "standards of naturalness" by which to judge the health of parks, he really is recommending ceilings on wildness" that will limit and restrict natural processes to the point that wilderness is no longer wild. He advocates a very well-behaved sort of nature, and many wilderness advocates want no such thing. The debate goes on.

The agencies charged with managing fire and other wilderness processes are exposed to many proposals for how to do our jobs better. If we're smart, we'll listen, and we'll know how to respond to the good ideas. But until the fire dialogues rise above their participants' separate convictions that each of them is the only one with a true understanding of nature, polemicists and position-takers will continue to run amok in the woods, and fire and fire policy will continue to be misunderstood.

In the meantime, we in the NPS will rely on the best science-and the most persuasive scientific consensus-we can find. And in the meantime, we invite any interested readers with questions to contact us directly (Office of the Superintendent, P. 0. Box 168, Yellowstone National Park, WY 82190). We are proud of our science program, and awed by Yellowstone's endless capacity to teach and inspire us. More than 200 researchers-federal, university, and independently funded-work in Yellowstone in a typical year, and their findings deserve as much attention as we can give them. We suggest that there is a better example than Zeus and his thunderbolts-Dr. Bonnicksen's image-to describe our fire-management program. Mythology tells us that fire was brought to man by the wise Prometheus, whose name means forethought.

The example of Prometheus is particularly apt because our fire-management goal, which is to restore or maintain natural fire regimes, cannot be achieved by merely letting fires burn. Restoration of natural fire regimes requires foresight-knowledge of the consequences of restoring natural fire.

This foresight is provided by research on fire history and effects. Far from having an "anti-scientific-management" philosophy, resource managers in Sequoia and Kings Canyon Parks work in conjunction with an active, cooperative research program aimed at providing the scientific information necessary to achieve specific fire-management goals. Prescriptions that define how, when, and where fires are allowed to burn-whether those fires are ignited by lightning or by fire managers-are based on that research program.

Space prohibits more than a cursory review of fire research in these parks. To provide a yardstick for judging success in restoring natural fire, we need to know the frequency, season, intensity, and size of fires that burned before Europeans arrived. Dr. Thomas Swetnam and his colleagues (University of Arizona) have found that tree rings of giant sequoias, when cross dated against a master tree-ring chronology, reveal a rich and detailed history of fires over the last 2,000 years or more. Recently completed chronologies already have provided the longest and most accurate assessment of fire frequencies for any forest type.

Additionally, microscopic examination of fire scars within individual annual rings often reveals the time in a tree's growing season in which the fire occurred. This will help us pinpoint the season-perhaps to the nearest month-of many ancient fires. Sequoia tree rings sometimes show an abrupt increase in width (growth release) in the years following ancient fires. We are designing studies to test our suspicion that the magnitude of these growth releases is proportional to the number of canopy trees killed locally by a fire, thus providing a measure of past fire intensities. Finally, we use the spatial distribution of scarred trees to infer the size of ancient fires.

This information on natural fires provides a target for the parks' firemanagement program and a standard for judging program success. Unfortunately, practical considerations (such as economics, air quality, and safety) make it unlikely that the management target-a completely natural fire regime-will ever be reached. Thus it is important to understand the ways in which natural fires shaped forests, so that those aspects of natural fire regimes most critical to determining forest structure are identified and preserved. For example, if practical considerations make it difficult or undesirable to manage high-intensity fires in areas where they were found to be natural, can we substitute low-intensity fires and expect the same effects on forest structure? Preliminary results from our research on forest age structure, coupled with observations of effects of modern fires, suggest that most sequoias occur in nearly even-aged clumps which appear to have resulted from natural "hotspots" intense enough to kill the canopy locally. In order to maintain sequoia abundance, therefore, we may have to let at least some managed fires burn with patchy high intensity.

Other cooperative studies model fuel accumulation under fire suppression and different fire regimes (Dr. J. van Wagtendonk, National Park Service), examine charcoal and pollen from meadow sediments to determine longterm changes in fire and vegetation (Dr. R. S. Anderson, Northern Arizona University), evaluate visitor perceptions of prescribed fire (Dr. J. Quinn, California State University, Fresno), examine the interactions of fire and forest pathogens (Dr. D. Piirto, California State University, San Luis Obispo, and Dr. J. R. Parmeter, University of California, Berkeley), and record soil and cambial temperatures to determine heating under different burning conditions (S. Sackett and S. Haase, U.S. Forest Service).

Curiously, Dr. Bonnicksen referred to some early results of the latter study -to which he was introduced when we gave him an on-site tour of our fire-research program in 1988-to bolster his contention that fire management in Sequoia and Kings Canyon National Parks lacks a scientific basis. On the contrary, one goal of Sackett's and Haase's soil-temperature work is to determine the relationship between burning conditions and soil temperatures. The results, together with the information we are gathering on the effects of different fire intensities on vegetation, provide a scientific basis to adjust our burn prescriptions if necessary.

Prometheus, by the way, had a scatterbrained brother named Epimetheus, which means afterthought. Dr. Bonnicksen is correct in stating that research funds are too precious to spend on fending off criticism. It is our intention to use those funds to make the prescribed-fire program of these parks a model of scientifically guided fire management, in which information needs are anticipated, obtained, and used in the planning process, rather than gathered as an afterthought. AF