Pests, climate change put whitebark pine at risk

Ravaged by an introduced pest and facing threats from climate change, stands of whitebark pine are disappearing so quickly from the Western landscape that the species needs federal protection, conservation groups say.

On Tuesday, the Natural Resources Defense Council petitioned the U.S. Fish and Wildlife Service to add whitebark pines to the Endangered Species List.

The trees grow at high elevations, where their seeds provide high-calorie meals for grizzly bears. In Yellowstone National Park, fewer bear-human conflicts are reported during years of abundant seed crops.

“The whitebark pine is central to many of North America’s mountain ecosystems, and its loss would be devastating to our most iconic landscapes,” said Sylvia Fallon, lead author of the council’s petition.

Whitebark pine habitat is scattered throughout the West, including parts of the Selkirk and Cascade ranges. Scientists call it a “keystone” species for its role colonizing inhospitable sites, said John Schwandt, the U.S. Forest Service’s whitebark pine program coordinator, who is based in Coeur d’Alene.

The pine’s fat-laden seeds are favorites of grizzlies, squirrels and a jay-like bird called Clark’s nutcracker, which stores the seeds in caches raided by other animals. Whitebark pine trees don’t start producing seeds until they’re 50 years old.

“Because they grow in such harsh conditions, they’re slow all the way,” Schwandt said. After five decades, a tree might reach 3 feet in height. Seeds take two years to sprout. Once established, however, whitebark pines can live to 1,200 years.

A European blister rust has knocked the hardiness out of the species. The fungus weakens the trees, leaving them susceptible to attacks by native mountain pine beetles. The trees also face threats from warmer temperatures, which have expanded the pine beetle’s range into higher elevations, according to the Natural Resources Defense Council’s petition.

Schwandt examined two dozen whitebark pine stands from Yellowstone to the Selkirks last summer. Beetles had killed 75 percent to 90 percent of the mature, cone-bearing trees. In North Idaho, scattered whitebark pine stands once covered 200,000 acres. Only 4,000 acres remain.

Schwandt isn’t sure how great a role climate change plays. “These trees have managed climate change over the past 1,000 years and seem to manage,” he said. But the warmer temperatures do favor competitor trees, which are moving higher in elevation, Schwandt said.

Two years ago, the Bonners Ferry Ranger District burned 1,000 acres of ridgetops to clear the ground for whitebark regeneration. The Forest Service Nursery in Coeur d’Alene also grows blister rust-resistant strains of the trees.

In addition to their role in the natural ecosystem, whitebark pines define the high-country experience for many hikers, Schwandt said.

“When you see whitebark pine, you really know that you’re at the top of the world,” he said.