Assessing the combined effect of climate change and herbivores' activities on the tundra

From a plant’s point of view, what exactly will happen as the climate changes? Depending how its neighbors fare, one species might be more successful at grabbing space and resources. But, as conditions warm and the range of herbivores is altered, this will affect the plant community, too. The overall effect of climate change will surely be a combination of both factors, as Guillermo Bueno set out to test for the first time.
Studying Alpine plants of the Canadian Yukon, he is assessing the effects on plants of removing their neighbors, pruning a full third of their leaves to simulate grazing, and examining the impact of actual grazing by small mammals called pikas. Pikas live only about 5 years, but, across generations, their grazing can go on for decades. Measuring plants’ total biomass in the end reveals who is “winning” this complex competition. Dr. Bueno’s approach combining climate- and herbivore-induced changes goes further than past studies by identifying the precise mechanisms at play. His work could help predict for this and other ecosystems the risks of a changing climate.