PARENT SESSION
Oral Session #2: Riparian Ecology.
Presiding: M. Dixon
Monday, August 5. 8:00 AM to 11:30 AM. Greenlee Meeting Room, TCC.
Pacific salmon, nutrients, and the dynamics of freshwater and riparian ecosystems.
Naiman, Robert*,1, Bilby, Robert2, Schindler, Daniel1, Helfield, James1, Bartz, Krista1, O'Keefe, Thomas1, Drake, Deanne1, 1 University of Washington, Seattle, WA2 Weyerhaeuser Company, Federal Way, WA
ABSTRACT- Pacific salmon (Oncorhynchus spp.) accumulate substantial nutrients in their bodies as they grow to adulthood at sea. These nutrients are carried to predominantly oligotrophic lakes and streams, being released during and after spawning. Research over >3 decades has shown that the annual deposition of salmon-borne, marine-derived nutrients (MD-nutrients) is important for the productivity of freshwater communities throughout the Pacific coastal region. However, pathways and mechanisms for MD-nutrient transfer and accumulation in freshwater ecosystems are virtually unexplored with many uncertainties remaining. This presentation addresses two related topics. First, we summarize recent advances in understanding linkages between MD-nutrients, freshwater (including riparian) ecosystems and community dynamics by addressing the importance of MD-nutrients to lakes, streams, and riparian vegetation and by then reviewing large scale and long-term processes in the atmosphere and ocean governing variability in salmon populations. Second, we evaluate the "validity" of the discoveries and their implications for active ecosystem management, noting areas where extrapolation of results still requires extensive caution. Collectively, the data suggest that the fresh water portion of the salmon production system is intimately lined to the ocean and therefore, to be sustainable, it will require a holistic approach to management. This holistic approach, presented in a conceptual framework, treats climate cycles, salmon, riparian vegetation, predators, and MD-nutrient flowpaths and feedbacks as an integrated system.
KEY WORDS: Pacific Salmon, MDN, riparian ecosystems