Adaptive Management of Forest Ecosystems: Did Some Rubber Hit the Road?

摘要

Although many scientists recommend adaptive management for large forest tracts, there is little evidence that its use has been effective at this scale. One exception is the 10-million-hectare Northwest Forest Plan, which explicitly included adaptive management in its design. Evidence from 10 years' implementation of the plan suggests that formalizing adaptive steps and committing to monitoring worked better than allocating land to adaptive management areas. Clearly, some of the problems in implementing any new strategy should have been expected and probably would have been avoided if the plan had called for even more focused feedback. But decisions made after monitoring results were analyzed have led to new management priorities, including new approaches to adaptive management. These decisions suggest that one adaptive management loop has been completed. A continued commitment to learning about and adapting practices and institutions will most likely be needed to improve performance in the future.nnWe explore the concepts of adaptive management as they were developed in a regional-scale scientific assessment (FEMAT 1993) and applied on federal lands through the Northwest Forest Plan (USDA and USDI 1994). By the early 1990s, federal land managers, who are responsible for managing roughly a third of the forests in the Pacific Northwest, were confronted with difficult issues concerning the harvesting of old-growth forests; the decline of northern spotted owl, marbled murrelet, and salmon populations; and the social well-being of forest-dependent rural communities. The controversy over those issues—and a 1991 court-mandated injunction on timber harvesting, issued in response to threats to the northern spotted owl—led to a presidential summit in 1993 in Portland, Oregon. President Clinton issued a mandate for a plan to resolve the conflict between timber and other resources by using the following five principles (FEMAT 1993): Never forget the human and economic dimensions of the problem.n n Protect the long-term health of forests, wildlife, and waterways.n n Be scientifically sound, ecologically credible, and legally responsible.n n Produce a predictable and sustainable level of timber sales and nontimber resources.n n Make the federal government work together and work for its citizens.n nnnThe process used to write the plan had never been tried before, but it has become a model for many other planning efforts nationally and internationally. A team of federal scientists, the Forest Ecosystem Management Assessment Team (FEMAT), was commissioned to write a science-based assessment (FEMAT 1993) that developed and analyzed a range of alternatives to be applied to all 10 million hectares of federal land in the region. Planning hitherto had been confined to smaller forest, district, and project scales. The assessment fed directly into a traditional planning process and ultimately into a record of decision (USDA and USDI 1994). Scientists had never before wielded so much influence over policy. The resulting plan was a watershed in the management of federal forest lands: Giving ecological concerns priority led to placing 80 percent of the land in late-successional and riparian reserves and reduced federal harvest projections by four-fifths. The FEMAT focus on developing an approach based on conservation biology was to be expected, given the injunction over the owl. What was more surprising, and less widely appreciated, was the addition of a regional adaptive management program. In effect, the plan chose adaptive management as its cornerstone (Pipkin 1998, Stankey et al. 2003) because of the explicitly acknowledged uncertainties in the conservation biology approach and in the likely ecological and social outcomes (FEMAT 1993).nnThe origin of adaptive management can be traced back to the ideas of scientific management pioneered by Frederick Taylor in the early 1900s (Haber 1964, Bormann et al. 1999).Various perspectives on adaptive management are rooted in parallel concepts found in business (total quality management and learning organizations; Senge 1990), experimental science (hypothesis testing; Popper 1968), systems theory (feedback control; Ashworth 1982), and industrial ecology (Allenby and Richards 1994). The concept has gained attention as a means of linking learning with policy and implementation (Stankey et al. 2005). Although the idea of learning from experience and modifying subsequent behavior in light of that experience has long been reported in the literature, the specific idea of adaptive management as a strategy for natural resource management can be traced to the seminal work of Holling (1978), Walters (1986), and Lee (1993).nnIn this article, we define adaptive management as a systematic and iterative approach for improving resource management by emphasizing learning from management outcomes. Adaptive management is not simply changing management direction in the face of failed policies; rather, it is a planned approach to reliably learning how to improve policies or management practices over time in the face of uncertainty. Adaptive management requires exploring alternative ways to meet management objectives, predicting the outcomes of alternatives based on what is known, implementing one—or if possible, more than one—of these alternatives, monitoring to learn which alternative best meets the management objectives, and then using results to update knowledge and adjust management actions. Adaptive management is not an end in itself, but a means to more effective decisions and enhanced benefits; thus, its true measure is in how well it helps meet environmental, social, and economic goals, adds to scientific knowledge, and reduces tensions among stakeholders.nnBefore the Northwest Forest Plan, federal forest managers had not institutionalized adaptive management at any scale. Although managers have a long history of trying innovative treatments, typically these were applied on small scales, with inadequate experimental design, without broad coordination, and, more often than not, without monitoring. More important, learning was rarely considered a legitimate task for managers; learning was the task of researchers, who transferred “technology,” usually in a one-way fashion, to managers. Typically, research-based learning was from retrospective studies; from well-designed, small-scale experiments with narrowly constructed treatments; and from models. The Northwest Forest Plan called for learning that would evaluate large-scale, complex management strategies well enough to drive changes in those strategies.nnScientists generally see adaptability as essential to managing complex, poorly predictable ecosystems (Walters 1986). Thus, most ecosystem assessments call for adaptive management (Ayensu et al. 1999). But when the scientists look back to assess the results of applying adaptive management, they are often disappointed in what managers have been able to implement (Walters 1997, Stankey et al. 2003). A continued drumbeat of failure will, at some point, lead people to question whether adaptive management is a viable concept or a hollow marketing tool. Here we examine the role of adaptive management as it led to, and played out in, the implementation of the Northwest Forest Plan in its first decade.