The Aquatic Conservation Strategy of the Northwest Forest Plan—A Review of the Relevant Science After 23 Years
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Synthesis of Science to Inform Land Management Within the Northwest Forest Plan Area Volume 2 Thomas A. Spies, Peter A. Stine, Rebecca Gravenmier, Jonathan W. Long, and Matthew J. Reilly, Technical Coordinators U.S. Department of Agriculture Forest Service Pacific Northwest Research Station Portland, Oregon General Technical Report PNW-GTR-966 Vol. 2 June 2018 Synthesis of Science to Inform Land Management Within the Northwest Forest Plan Area Chapter 7: The Aquatic Conservation Strategy of the Northwest Forest Plan—A Review of the Relevant Science After 23 Years Gordon H. Reeves, Deanna H. Olson, Steven M. Wondzell, to develop a network of functioning watersheds that supports Peter A. Bisson, Sean Gordon, Stephanie A. Miller, populations of fish and other aquatic and riparian-dependent Jonathan W. Long, and Michael J. Furniss1 organisms across the NWFP area (USDA and USDI 1994a). The ACS is based on preserving and restoring key ecological Introduction processes, including the natural disturbance regimes (USDA The Aquatic Conservation Strategy (ACS) is a regional and USDI 1994a) that create and maintain habitat for native strategy applied to aquatic and riparian ecosystems across aquatic and riparian-dependent organisms, and it recognizes the area covered by the Northwest Forest Plan (NWFP, that periodic natural disturbances may be required to sustain or Plan), encompassing broad landscapes of public lands ecological productivity. As a result, the ACS does not expect administered by the U.S. Department of Agriculture Forest that all watersheds will be in favorable condition (highly Service and the U.S. Department of the Interior Bureau of productive for the same aquatic organisms) at any point in Land Management (BLM) (USDA and USDI 1994a). The time, nor does it expect that any particular watershed will ACS was developed during the analysis (FEMAT 1993) that remain in a certain condition through time. If the ACS and led to the NWFP, but its foundation was a refinement of the NWFP are effective, the proportion of watersheds in earlier strategies: the Scientific Panel on Late-Successional better condition (for native organisms) is expected to remain Forest Ecosystems (“The Gang of Four”) (Johnson et al. the same or increase over time (Reeves et al. 2004). 1991), PacFish (USDA and USDI 1994b), and the Scientific The primary objective of the ACS is to maintain Analysis Team (Thomas et al. 1993). and restore the distribution, diversity, and complexity of The ACS uses an ecosystem approach to management of watershed-level features and processes to which aquatic and riparian and aquatic habitats (Everest and Reeves 2007) and riparian species are uniquely adapted. Programs and actions was designed to (1) protect watersheds that had good-quality under the ACS are to maintain, not prevent, attainment of habitat and strong fish populations at the time the Plan was this goal. The ACS designates watershed analysis as the tool drafted, and (2) halt further declines in watershed condition for developing baseline conditions against which to assess and restore ecological processes that create and maintain maintenance and restoration conditions, and improvements favorable conditions in aquatic ecosystems in degraded eco- in biological and physical processes are to be evaluated systems (FEMAT 1993). The long-term goal (100+ years) is relative to the natural range of variability (USDA and USDI 1994a). ACS objectives address (1) diversity and complexity of watershed features; (2) spatial and temporal connectivity within and between watersheds; (3) physical integrity; (4) 1 Gordon H. Reeves is a research fish ecologist, Deanna H. Olson is a research aquatic ecologist, and Steven M. Wondzell water quality; (5) sediment input, storage, and transport; (6) is a research geologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson instream flows (e.g., both peak and low flows); (7) floodplain Way, Corvallis, OR 97331; Jonathan W. Long is a research inundation; (8) riparian plant-species composition and ecologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 1731 Research Park, Davis, CA structural diversity; and (9) habitat to support well-distrib- 95618; Peter A. Bisson is a research fish ecologist (retired), U.S. Department of Agriculture, Forest Service, Pacific Northwest uted populations of native, aquatic and riparian-dependent rd Research Station, 3625 93 Avenue SW, Olympia, WA 98512; species of plants, invertebrates, and vertebrates. Michael J. Furniss is a hydrologist (retired), U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, The ACS sets out five components to meet its goals: 1700 Bayview Drive, Arcata, CA 95521-6013; Sean Gordon is a research assistant professor, Institute for Sustainable Solutions, • Riparian reserves: Riparian reserves are specif- Portland State University, 1600 SW Fourth Avenue, Portland, OR ically designated portions of the watershed most 97204; Stephanie A. Miller is the Riparian Program lead, U.S. Department of the Interior, Bureau of Land Management, 20 M tightly coupled with streams and rivers that provide Street SE, Washington, DC 20001. 461 GENERAL TECHNICAL REPORT PNW-GTR-966 the ecological functions and processes necessary to efforts prior to 1993. The ACS, along with PACFISH (USDA create and maintain habitat for aquatic and riparian- and USDI 1994b) and the riparian component of the Tongass dependent organisms over time, as well as habitat Land and Resource Management Plan (USDA FS 1997), connectivity within and between watersheds. The made two substantive changes in how riparian management reserve boundaries were considered interim until was formulated (Everest and Reeves 2007). First, they a watershed analysis was completed, at which time addressed riparian management at the watershed scale they could be modified based on suggestions made in (5th- to 6th-code hydrologic units), with specific emphasis the watershed analysis. on maintaining ecological functions over the long term. • Key watersheds: 5th-code (40,000 to 250,000 ac Second, they rejected the previous philosophy of trying to [16 187 to 101 171 ha]) to 6th-code (10,000 to 40,000 define and achieve the absolute minimum set of practices ac [4047 to 16 187 ha]) hydrologic units that were that would meet stated riparian-management goals, and the intended to serve as refugia for aquatic organisms, concept that goals could be met by implementing yet another particularly in the short term for at-risk fish popula- set of best management practices. The new (at that time) tions, and had the greatest potential for restoration, management philosophy under the NWFP represented a par- or to provide sources of high-quality water. At the adigm shift in how managers viewed resource coordination. time the NWFP was drafted, Tier 1 key watersheds In previous riparian rule-sets, riparian and aquatic technical had strong populations of fish, productive habi- specialists shouldered the “burden of proof” to demonstrate tat that was in good condition, or high restoration resource damage from forestry activities and the need for potential. Tier 2 key watersheds provided sources of more comprehensive forest-practices rules to meet ripari- high-quality water. an-management goals. Under the NWFP, the precautionary • Watershed analysis: An analytical process that principle was invoked—the burden of proof shifted (Thomas characterizes the features and processes of water- et al. 2006, USDA and USDI 1994a). Forest managers who sheds and identifies potential actions for address- wanted to alter the comprehensive default prescriptions for ing problems and concerns, along with possible riparian management under the NWFP (described above) management options. It assembles information nec- to pursue other management goals were required to demon- essary to determine the ecological characteristics strate through watershed analysis that changes would not and behavior of the watershed and contribute to the compromise established riparian-management goals. development of options to guide management in This chapter focuses on the scientific literature related the watershed, including adjusting riparian- to the management and conservation of aquatic ecosystems, reserve boundaries. particularly as it has developed since the 10-year NWFP • Watershed restoration: Includes actions deemed review (Reeves 2006), with particular emphasis on the area necessary to restore degraded ecological processes of the NWFP. Among the key issues considered are: and habitat. Restoration activities focus on restoring • The ecological, physical, and biological importance the key ecological processes required to create and of headwater and intermittent streams. maintain favorable environmental conditions for • The contribution of periodic disturbances to the aquatic and riparian-dependent organisms. resilience and productivity of aquatic ecosystems. • Standards and guidelines: These directives impose • The inherent variation of aquatic ecosystems in specific requirements (standards) or recommended space and time. approaches (guidelines) for management activities in • A better understanding of the variation in where key riparian reserves and key watersheds. ecological processes occur within the stream net- work and the development of new tools to identify Note that a key philosophical shift occurred in the these locations. development of the ACS and NWFP as compared with 462 Synthesis of Science