Ravaged by an introduced pest and facing threats from climate change, stands of whitebark pines are disappearing rapidly from the West’s high-elevation forests.
The gnarly looking pines, whose fat-laden seeds are an important grizzly food, could be extinct within 120 years, U.S. Fish and Wildlife officials said Monday. While the trees are worthy of federal protection, officials said whitebark pines won’t be listed under the Endangered Species Act at this time because of budget constraints and higher priorities within the agency.
But whitebark pines will remain a candidate for listing, and the tree’s status will be reviewed annually. Most of the whitebark pine habitat occurs on federal land, where efforts are already under way to protect remaining trees.
“The rapid decline of whitebark pine is one of the most dramatic signs of how quickly our mountain ecosystems are warming,” said Sylvia Fallon of the Natural Resources Defense Council, which petitioned the Fish and Wildlife Service in 2008 to add the tree to the endangered species list.
Whitebark pine habitat is scattered throughout the West, including parts of the Selkirk, Bitterroot and Cascade ranges in Idaho, Montana and Washington. Scientists consider it a “keystone” species for its role in colonizing inhospitable sites.
The trees grow on wind-swept ridges at elevations of 5,500 feet and higher, where they block the wind and prolong snowmelt. Their high-calorie seeds are favorites of grizzlies, squirrels and Clark’s nutcracker, a jay-like bird that stores the seeds in caches raided by other animals.
The slow-growing pines don’t start producing seeds until they’re 50. Once established, whitebark pines can live 500 to 1,000 years. Their picturesque broken tops and twisted branches are frequently photographed by hikers.
Concerns about the whitebark pine’s long-term survival, however, have been raised since the early 1980s.
About 80 percent of the whitebark pine forests in the Greater Yellowstone ecosystem are dead or dying from disease and beetle attacks, according to the Natural Resources Defense Council. Stands in the Idaho Panhandle also have high mortality rates, said Art Zack, the Idaho Panhandle National Forests silviculturist and ecologist.
A European blister rust knocked the vigor out of the species. The disease weakens the trees, leaving them susceptible to attacks by native mountain pine beetles. The trees also face threats from warmer winters, which have expanded the pine beetles’ range into high elevations, according to the Fish and Wildlife Service.
Wildfire suppression also contributed to the whitebark pine’s decline. Without large openings, the trees have trouble regenerating.
“It’s the combination of all three of these things going on simultaneously that has made the threat so dire,” Zack said. “The situation is pretty urgent, because we’re losing so many of the seed trees.”
The Forest Service Nursery in Coeur d’Alene grows blister-rust resistant strains of the trees, which the agency uses in restoration projects. Despite efforts to re-establish whitebark pine, the long-term prognosis is grim.
While pockets of individual trees might survive, whitebark pine forests are likely to disappear from the landscape, U.S. Fish and Wildlife officials said.
Conservation groups fear that will create gaps in the ecosystem, eliminating a critical food source for grizzlies. In Yellowstone National Park, fewer bear-human conflicts are reported during years of abundant seed crops.
But Fish and Wildlife officials said that grizzlies’ versatile eating habits will help them survive the loss of whitepark pine nuts. The seeds aren’t a reliable food source, and “grizzlies have been coping for millennia by switching to other food when whitebark pine seeds are not available,” officials said.