New Forestry Principles from Ecosystem Analysis of Pacific Northwest Forests.

Forest management practices on Federal lands in the Pacific Northwest of the United States have been the center of intense controversy. Conflicting value systems, new information, and new perspectives have fueled the debate over the balance between timber production and preservation of natural ecosystems. In this paper we consider examples from three aspects of forest management: (1) management of forest stands, (2) management of the patchwork of forest stands at the landscape scale, and (3) management of streams and riparian networks. In each of these cases we examine: management practices and perspectives of the recent past, findings from ecosystem research that are leading to change in those practices, resulting changes in management practices, and future research directions. We also suggest a path for future change, including systems for managing in the face of uncertainty. Results of research in natural and managed forest and stream ecosystems have been pivotal in reassessment and redesign of management practices to provide a broader range of management options for society to consider. Results of studies of natural disturbance processes and their effects are used as reference points for management systems intending to sustain biological diversity and ecosystem productivity. Stand management practices, for example, are being modified to retain some live trees and greater amounts of dead woody debris, both standing and down, in areas that would instead be clear-cut under intensive plantation forestry practices. The motivations for these modified practices are to sustain biological diversity, including key wildlife species, and to maintain soil productivity. Models of alternative forest-cutting patterns at a landscape scale are being used to examine their effects on ecosystem structure and function. One result of this analysis has been to shift from the previous system of dispersing cutting units to a system involving greater aggregation of units using designs to provide for species preferring forest interior habitat as well as species favoring edge and early seral habitats. As a result of ecosystem research, the management of stream and riparian networks can now be based on understanding of forest-stream interactions and designed within a drainage-basin context. Overall, emphasis in research and management seems to be in early stages of shifting from featured species-e.g., Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and Northern Spotted Owl (Strix occidentalis caurina)-to ecosystems, and from the scale of forest stands to landscapes and the entire region. In addition to the contributions of ecosystem research to redesign of management techniques, ecosystem scientists also have roles in the social processes for determining the future course of management of natural resources. An important medium for scientist participation is establishment of adaptive management programs, in which management activities are conducted as experiments to test hypotheses and to develop information needed for future natural resource management.