1. Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
2. Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, ON K1S 5B6, Canada
3. Fisheries and Oceans Canada Cooperative Resource Management Institute, School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
4. Department of Forest Sciences, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada