MANAGING FOR UNCERTAINTY:
AS ECOLOGICAL RESERVES
David M. Graber
[Summary of remarks at the session: How Can Science be Used More Effectively to Manage National Park Resources? Annual Meeting of the American Association for the Advancement of Science, May 26-31, 1985, Los Angeles, California.]
OLICIES THAT DIRECT environmental management must be dynamic. As knowledge accumulates and new models replace older ones, goals that once made sense are seen in new light to be irrelevant, self-contradictory, or inappropriate. Policy dynamics reflects changes in societal values, changes in models of the natural world, and interactions of those elements. It has now been 20 years since the Leopold Committee presented its report to Secretary of the Interior Udall (Leopold et al. 1963) and provided park managers with an integrated and coherent basis for the stewardship of national park natural [and now wilderness] areas. The impetus for calling the committee had been recent removal by National Park Service staff of more than 4,000 elk from Yellowstone National Park by shooting, and controversy over whether it was proper to kill native animals in national parks, and who should do the killing. Leopold and his fellow scientists did not dispute that periodic removal of native ungulates from national parks was an appropriate management tool: "Good park management requires that ungulate populations be reduced to the level that the range will carry in good health..." They supported the Park Service action.
Nearly 20 years later, after exhaustive field study and a review of historical material, Houston (1982) largely refuted both the empirical basis and the conceptual framework of the Leopold Committee's findings on Yellowstone's Northern Elk Herd. Not only did Houston find little basis for the claim that elk range was overgrazed, and the herd
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itself above carrying capacity, but he suggested that the Park Service had been implicitly managing for the kind of ecological "scene"—that is, ecosystem structural elements, process elements, and their interactions—that it found appealing: lush vegetation, fat elk, and unburned forests. As if recognizing that this paradigm shift, resulting from a new ecological model and altered philosophical viewpoint, may be repeated in the future, Houston called for "experimental management," in which hypotheses may be generated and tested in a monitored and sometimes experimentally manipulated environment within the national parks.
The lesson of recent decades in the national parks and other large ecological reserves has been that ecology is rather more complicated than had previously been assumed, and consequently that "natural resource management" is not yet—and may never be—at the stage envisioned by the Leopold Committee in 1963 when it bequeathed the Park Service a noble vision:
"As a primary goal, we would recommend that the biotic associations within each park be maintained, or where necessary recreated, as nearly as possible in the condition that prevailed when the area was first visited by the white man. A national park should represent a vignette of primitive America." .....Leopold et al. 1963:32.
That vision raised the possibility of reintroducing extirpated species, controlling or eliminating exotics, and population management where natural controls no longer operated effectively. Fire was recommended as a tool to restore seral communities and reverse the mischief of many decades of natural fire suppression. It called attention to the growing truth that national parks were becoming ever more insular and subject to all the ailments of ecological islands. Parks were no longer in a condition to take care of themselves. The vision provided direct impetus for development of a professional cadre of scientists and resource management specialists within the National Park Service.
The Leopold Report supported management of park ecosystems as static scenes, and made the implicit assumption that ecology and its applications tools were sufficiently advanced to accomplish such an end. For example, taken literally a "primitive vignette" of western pyrophytic communities would have required perpetual simulation of the often-profound effects of Indian burning to recreate the landscape first seen by Europeans. Yet such a landscape undoubtedly was the nexus of a particular point in Indian cultural evolution, post-Pleistocene plant community succession, and contemporary climatic conditions. Moreover, although some have claimed that the composition of such communities now 1 or 2 centuries past can be determined by analysis of present-day structure and historical records (e.g., Bonnicksen and Stone 1982), such determinations are limited in scope and accuracy. No doubt new techniques will be developed and refined to improve the ac-
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curacy of ecological recreations, but such an objective is incompatible with the changing function of national parks.
As wild ecosystems are progressively compromised by a variety of human activities such as mining, grazing, logging, recreation, and settlement, what is left becomes increasingly valuable as laboratories of natural ecological processes. The wildernesses of our large national parks will assume this role to an ever greater extent. Yet to function effectively in this capacity as ecological reserves, scene management must be replaced by management for the unimpeded interaction of native ecosystem processes and structural elements. Both structural elements, including plants and animals, soil and parent material, water and air; and system processes, such as photosynthesis, wildfire, and erosion would then be protected, as would be interactions among them. While park policy historically has variously compelled, encouraged, and permitted intervention in ecosystems in order to enhance or inhibit different physical elements such as scenery or wildlife by influencing processes such as wildfire, predation, or erosion, the changing role of national parks and more sophisticated ecological understanding has reduced the perceived need for intervention to an extremely limited set of cases: (1) To reverse or mitigate anthropogenic factors where knowledge and tools exist to do so; (2) To protect a featured resource; and (3) To protect human life and property.
Several national parks have been dedicated as International Biosphere Reserves under UNESCO's Man and the Biosphere Program. This designation acknowledges the increasing scientific value of national parks as sites for study of natural ecosystem functioning and as controls against which human-induced changes in the rest of the world may be measured. In turn, such increased scientific presence in the national parks can be expected to provide new knowledge for park managers, and perhaps the kinds of subtle tools necessary to reverse or mitigate anthropogenic influences without excessive interference in natural processes.
Parks today are profoundly threatened with a new class of influences: regional and global phenomena such as air pollution and acidic deposition, aquatic pollution, enhanced atmospheric carbon dioxide, and increasing insularity resulting in growing boundary effects. In many ways parks are also the ideal sites to study these problems, because the problem of "intervening variables" is considerably less than on manipulated sites. Benefits from such studies accrue not only to the park study sites, but to society in general.
Such use of parks as natural laboratories is not without cost. Where recreation conflicts with scientific investigation it might have to be restricted. And some kinds of research—valuable as they may be—are aesthetically offensive and destructive of the natural landscape. Clearly a sophsticated kind of balance must be struck between cost to park values and potential benefits within and without the park.
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Managing parks as unimpeded natural ecosystems introduces its own host of difficulties. Prior to intervention, determination must be made whether a particular phenomenon—population irruption or collapse, wildfire, forest dieback—is natural or anthropogenic. Some of these events conflict directly with the aesthetic and recreation functions of national parks. By abandoning the notion of a desired "end product," it is much more difficult for park managers to measure their own success. And until our scientific database and understanding of ecological processes is substantially greater than it is today, this "managing for uncertainty" will be more of an ideal than an attainable objective. Happily, ecological and ecosystem-level research is becoming ever more prevalent in national parks, providing some kind of counterpoint to increasing threats to the parks' survival as viable entities.
Bonnicksen, T. M., and E. C. Stone. 1982. Managing vegetation within US national parks: a policy analysis. Environ. Manage. 6(2):101-102, 109-122.
Houston, D. B. 1982. The northern Yellowstone elk. Macmillan, Riverside, NJ. 474p.
Leopold, A. S., S. A. Cain, D. M. Cottam, I. N. Gabrielson, and T. L. Kimball. 1963. Wildlife management in the national parks. Trans. North Am. Wildl. Nat. Res. Conf. 28:28-45.
David M. Graber, Research Scientist, Sequoia and Kings Canyon National Parks, California.