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Tuesday, May 27, 2008 - 10:15 AM
134
Influences of Pacific Salmon on stream ecosystems: A quantitative literature synthesis
David J. Janetski, Dominic T. Chaloner, Scott D. Tiegs, and Gary A. Lamberti. Department of Biological Sciences, University of Notre Dame, 290 Galvin, Notre Dame, IN 46556-0369
Pacific salmon (Oncorhynchus spp.) can function as both nutrient resource subsidies and agents of benthic disturbance in the freshwater ecosystems in which they spawn and die. Enrichment and disturbance by spawning salmon can be powerful ecological forces, but the contribution of environmental factors to variation in these two processes remains unclear. To identify relationships between environmental factors and the effect of salmon on various response variables in stream ecosystems, we conducted a meta-analysis of 36 relevant publications from the primary literature. Results indicated a positive overall effect of salmon on streamwater nutrient concentrations and algal abundance, but the magnitude of the effect varied considerably among response variables. Ammonium concentrations, for example, increased on average by 500% in the presence of salmon while dissolved organic carbon increased by only 20%. The effect of salmon on streamwater nutrient concentrations was positively correlated with salmon biomass. Increases in algal abundance during salmon runs were significantly larger on large pebble- to cobble-sized substrates. We conclude that the physical stream environment (1) modulates the magnitude of ecological effects attributable to salmon and (2) determines whether the predominant role of salmon is nutrient enrichment or physical disturbance.
Web Page: salmon, streams, meta-analysis
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
See more of Contributed Sessions
See more of The Nabs 56th Annual Meeting (25-28 May, 2008)