USDA Forest Service

Pacific Northwest Research Station - Ecological Process & Function - Wildlife Ecology Team


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United States Department of Agriculture Forest Service.

Biological Diversity Research

Conservation of Biological Diversity

• Improve understanding of the factors affecting biological diversity and ecosystem structure and function, including the role of human activity;

• Investigate alternatives and tools for conservation of biological diversity, including viability assessments for species of concern, development of broader ecosystem-based strategies, and analysis of functional roles of species and assemblages of species; and

• Develop scientific knowledge needed to enable the design and management of habitats to support both human uses and native biota. The ecological literature contains an active debate on the relative values of ecosystembased and species-based approaches to the conservation of biological diversity. A recent forum, “Preserving Biodiversity” (Ecological Applications 3(2), 1993:202-220) and subsequent letters to the editor (Ecological Applications 4(2), 1994:205-209) contain a lively debate that highlights why both approaches are necessary. As stated by Wilcove,“The distinction between ‘single-species management’ and ‘ecosystem management’ is a false dichotomy; both are part of a continuum of steps necessary to protect biodiversity Wildlife Ecology Team Problem Analysis October 10, 2002 Page 5 of 33 (Wilcove 1994). Ecosystem based approaches are needed because there are too many species to handle on a species-by-species approach: such an approach will exhaust available time, financial resources, societies patience, and scientific knowledge (Franklin 1993). However, as pointed out by Wilcove (1994), an ecosystem plan that fails to ensure a viable population of, say, marbled murrelets or northern spotted owls, would be considered a failure. Needs of individual species, whether species listed under the Endangered Species Act or other legislation or species afforded special status in their role as keystone or umbrella species, are a vital part of any conservation strategy. Therefore, studies undertaken by the Wildlife Ecology Team address both ecosystem and species approaches.

A problem recognized by the Survey and Manage Office the Region 6 Office is that of the intractability of many concurrent single-species inventory, monitoring, and management activities, such as is currently evident in the Survey and Manage Species Program. Although management for species viability and biodiversity are specified in the National Forest Management Act and in agency policies pertaining to ecosystem management, much of this is interpreted in regulatory and operational procedures in terms of species-specific actions.

For example, organism- or species-based approaches can entail use of indicator or surrogate species (including umbrella, keystone, flagship, and focal species; e.g., Lambeck 1997, Niemi et al. 1997). Habitat- and site-based approaches can include identifying core habitats (such as “source habitats,” sensu Wisdom et al. 2000, Donovan et al. 1995) and habitat corridors or connections, using “coarse filter” assessments (sensu Haufler et al. 1996). Ecosystem-based approaches can include identifying functional groups of species (e.g., Marcot and Vander Heyden 2001, Stone 1995), and managing landscapes in light of disturbance regimes (e.g., Angelsgam 1998, Dale et al. 1998) and community- and ecosystems-level patterns and dynamics of food webs, energy flow, trophic structure, biodiversity patterns, and nutrient cycling (e.g., Kitchell 1992, Lawton and Brown 1994, Strange et al. 1999).

However, the efficacy of most such approaches is largely untested empirically, particularly in the Pacific Northwest. The development of scientific approaches to managing multiple species would greatly add to the array of potential tools that managers could consider. Such approaches require a broad review and synthesis of existing literature and case examples, and local empirical study of selected taxonomic groups of organisms. Some of our ongoing and proposed studies are designed to provide such understanding and testing. 1.1 Review of Multi-species Concepts and Assessments in a Decision Modeling


Pacific Northwest Research Station, Director’s Office, and the Regional Ecosystem Office requested a review and synthesis as a basis for exploring alternatives to the individual- Wildlife Ecology Team Problem Analysis October 10, 2002 Page 6 of 33 species approach used in the Survey and Manage Program. This study entails a major review and synthesis of multi-species ecological concepts and assessment methods, and decision analysis modeling approaches that could provide a framework for such assessments. The study consists of an extensive review of literature, models, methods, and case examples, and a synthesis of such information into matrixes that help the user determine what approach and tactic has been used to address specific kinds of multispecies problems or planning needs.

Team Lead: Bruce G. Marcot

USDA Forest Service - Pacific Northwest Research Station - Olympia Forestry Sciences Laboratory
Last Modified: Monday, 16 December 2013 at 14:18:50 CST

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