By Susan Milius
One of the Rube Goldberg effects of climate change — a dwindling winter snowpack that changes elk grazing habits — might end up as a major menace to the iconic aspen trees of the Rocky Mountains.
As the climate changes, winter snow isn’t building up as deeply and densely as it used to, explains ecologist Jedediah Brodie, now a Fulbright scholar working in Borneo. To study the winter dining habits of local elk, he and his colleagues set out motion-triggered cameras in northern Yellowstone National Park. They found that skimpier snow let elk do more foraging in the high stands of aspen when grazing grass died back in winter. And comparing fenced versus unfenced aspen shoots showed that grazing elk lowered the chances that young aspen shoots would survive to maturity, Brodie and his colleagues report online October 5 in Proceedings of the Royal Society B.
Brodie is concerned about aspen in areas with declining snowpack and increasing elk populations. “Climate change, in conjunction with elk, is tearing the recipe for aspen persistence out of the cookbook,” he says.