Climate Change and the Plight of the Whitebark Pine
By Editorial (The New York Times) - July 27, 2011
For centuries, the whitebark pine, Pinus albicaulis, has grown on hundreds of thousands of acres across the West. It is a keystone species of an entire ecosystem — one now seriously at risk. Most of the whitebark pines in Yellowstone and Glacier National Parks are dead. It has been declared an endangered species in Canada. And, last week, the Fish and Wildlife Service stated that the whitebark pine “warranted” listing as threatened or endangered, making it one of the very few species officially acknowledged as threatened by climate change.
Canada’s grim conclusion is that “none of the causes of decline can be reversed.” These include an invasive, foreign fungus and the suppression of forest fires, which are important in establishing pure stands of whitebark pine. But the most important threat is the spread of the native mountain pine beetle, which tunnels into the tree and lays its eggs under the bark. Historically, the pine’s defense against the beetle is living where conditions are too cold for it — at high altitude or at high latitudes. But as the climate warms, that defense has failed catastrophically.
The cascading effects of the white bark’s decline are already apparent. Grizzly bears, which feed heavily on pine seeds, have begun to disperse from their core habitat. When the pines were healthy, they also slowed snowmelt and reduced erosion. The tragedy is the ongoing demise of an ecosystem, one for which humans are culpable. What looks, from the air, like a plagued forest has been plagued by the choices we have made over the past century.