The purpose of this study was to review scientific knowledge and model projections on vegetation vulnerability to climatic and other environmental changes in the Pacific Northwest, with emphasis on five major biome types: subalpine forests and alpine meadows, maritime coniferous forests, dry coniferous forests, savannas and woodlands (oak and juniper), and interior shrub-steppe. We started by reviewing and synthesizing the scientific literature on past and projected changes in atmospheric carbon dioxide concentrations and climate for the Pacific Northwest (and globally), and how these changes are likely to influence snowpack dynamics, soil water availability, and selected disturbance regimes. We also reviewed and synthesized the scientific literature on plant growth, reproduction, and mortality in response to changing climate and disturbance regimes, and on the ability of plants to adapt to these changes through phenotypic plasticity, local adaptation, and migration. We then reviewed the strengths and weaknesses of several types of simulation models commonly used to project vegetation responses to climate change and discussed recent model projections of vegetation responses to future climate change scenarios in the Pacific Northwest, as well as how these projections might best be used in developing management plans for forests and rangelands. We next reviewed the existing scientific literature on plant sensitivity and adaptation to changing climate and disturbance regimes for five major vegetation biomes in the Pacific Northwest. We concluded with a discussion of current approaches and resources for developing climate change adaptation strategies, including restoring historical vegetation structure and composition, promoting resistance to change, promoting resilience to change, and facilitating anticipated responses to change.
Peterson, David W.; Kerns, Becky K.; Dodson, Erich K. 2014. Climate change effects on vegetation in the Pacific Northwest: a review and synthesis of the scientific literature and simulation model projections. Gen. Tech. Rep. PNWGTR-900. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 183 p.