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Quantifying fish responses to forestry—lessons from the trask watershed study

Informally Refereed

Abstract

We describe demographic processes and species interactions that infl uence Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) in small streams that are part of an eff ort designed to evaluate forest harvest impacts in the Trask Watershed, an industrial forest located in northwest Oregon, USA. Spatial variation in recruitment, individual growth, survival, and movement were quantifi ed during summer low fl ows for four years (2007–2010). Th e phenology of recruitment varied substantially among sites and years. Movement during summer was limited, and varied inconsistently among sites. Individual growth and survival showed consistent size-related patterns, with variability in growth showing more consistent diff erences among sites in diff erent years. Processes driving these patterns are challenging to identify, but companion studies of instream cover selection and seasonal diets of trout and other fi shes suggest strong roles for predators, species interactions, and seasonal food limitations. Based on these results, we fi nd that a process-based understanding of forestry impacts may prove more useful than traditional trend-based monitoring and impact assessments.

Parent Publication

Keywords

forest harvest, cutthroat trout, recruitment, cover selection, food availability.

Citation

Dunham, Jason; Bateman, Douglas; Hockman-Wert, David; Chelgren, Nathan; Leer, David. 2013. Quantifying fish responses to forestry—lessons from the trask watershed study. In: Anderson, P.D.; Ronnenberg, K.L., eds. Density management in the 21st century: west side story. Gen. Tech. Rep. PNW-GTR-880. Portland, OR: US Department of Agriculture, Forest Service, Pacific Northwest Research Station: 205-205.
https://www.fs.usda.gov/research/treesearch/45538