Abstract (from http://rspb.royalsocietypublishing.org/content/279/1732/1366.long): Altered species interactions are difficult to predict and yet may drive the response of ecological communities to climate change. We show that declining snowpack strengthens the impacts of a generalist herbivore, elk ( Cervus elaphus), on a common tree species. Thick snowpack substantially reduces elk visitation to sites; aspen ( Populus tremuloides) shoots in these areas experience lower browsing rates, higher survival and enhanced recruitment. Aspen inside herbivore exclosures have greatly increased recruitment, particularly at sites with thick snowpack. We suggest that long-term decreases in snowpack could help explain a widespread decline of aspen [...]
