Abstract

Ecological systems are already responding to modern changes in climate. Many species are moving in directions and at rates that correspond with recent climatic change. Understanding how species distributions and abundances are likely to be altered can inform management and planning activities resulting in more robust management.

We projected climate-driven changes in the abundances and distributions of 31 focal bird species in Oregon and Washington using the latest downscaled CMIP5 climate projections and corresponding vegetation model outputs.

We mapped these future projections and integrated them into an existing web-based tool to allow managers and planners to access and download the projections. Our model outputs forecast significant changes in vegetation across much of Washington and Oregon by the end of the century. These changes are particularly dramatic east of the Cascade Mountains. Our bird models project much less dramatic changes in avian communities across the two states, but those changes tend to be largest in the Olympic and Cascade Mountains as well as across portions of the Columbia Plateau and in eastern and southeastern Oregon. Despite the smaller changes in avian communities, our models do project significant changes in abundance for some species in specific locations ranging from large increases to local extirpations.

Our results also show that for some bird species, vegetation model projections are particularly important for forecasting changes in abundances and distributions. For example, Columbia Plateau Low Sagebrush Steppe and Shrubland, Northern Rocky Mountain-Vancouverian Montane-Foothill Grassland, and Great Basin and Intermountain (Sagebrush) Shrubland and Steppe were particularly important predictors for Oregon Vesper Sparrow (Pooecetes gramineus affinis). Dynamic general vegetation model (DGVM) outputs, such as fire, fuels, and carbon were important predictors of these habitat types.

In conclusion our results forecast significant climate-driven changes in vegetation for the region and highlight areas where nuanced management actions will be warranted.