Whitebark pine trees are being listed as 'threatened' under the Endangered Species Act due to threats to their existence/Diana Tomback

Whitebark pines, majestic trees that grow across Western national parks and feed birds and bears and serve as living snow fences, are at risk of disappearing due to disease, beetle attacks, and climate change and deserve protection as a threatened species under the Endangered Species Act, the U.S. Fish and Wildlife Service announced Wednesday.

Roughly 70 percent of the species' range lies within the United States, according to Fish and Wildlife staff, with the remaining 30 percent in Canada, where the trees can be found in all of that country's mountain national parks - Waterton Lakes, Banff, Kootenay, Yoho, Mount Revelstoke, Glacier, and Jasper.

More than a decade ago the agency was sued to consider listing the species, a "stone" pine that grows in the very highest reaches of Yellowstone, Glacier, Grand Teton, Olympic, Lassen Volcanic, Rocky Mountain, Yosemite, Sequoia, and Kings Canyon national parks.

Whitebark pine health is designated by the National Park Service as a "vital sign" of the subalpine ecosystems where it grows because it is a keystone species. This means that it is critical to the ecosystems' ecological function, supporting many other plants and animals that live there and influencing ecological processes like snow retention and spring run-off.

Declines in whitebark pine populations have been attributed to an interacting set of factors including blister rust disease, mountain pine beetle infestations, and climate change.

The trees produce a calorie-rich nut that grizzly bears in the Greater Yellowstone Ecosystem like to feast on in the fall. It's a nut that also feeds red squirrels and the Clark's nutcracker. For grizzlies, as the days grow shorter in fall and the temperatures drop, the bears spend most of their waking hours trying to pack on the pounds. Whitebark pine nuts are particularly nutritious, and in the Greater Yellowstone Ecosystem grizzlies seek out squirrel middens piled high with the pine cones to feast on.

Studies in the ecosystem have shown that when there's a good whitebark pine nut crop, sows gorge on them and head into hibernation both fatter and healthier.

“As a keystone species of the West, extending ESA protections to whitebark pine is critical to not only the tree itself, but also the numerous plants, animals, and watersheds that it supports,” said Fish and Wildlife Service Regional Director Matt Hogan in announcing the listing. “The Service now looks forward to continuing engagement with the many whitebark pine conservation partners during the recovery planning process to ensure this species continues to endure for future generations.” 

Scientists regard the tree as a “foundation species” because it creates the conditions necessary for other plants and animals to get established in harsh alpine ecosystems. 

While mountain pine beetle infestations are not uncommon in Western forests, global warming has allowed them to reach high-elevation whitebark pine forests where the trees have not evolved defenses against the beetles. Prior to climate change, harsh winters kept mountain pine beetles (which are the size of a grain of rice) at bay. Warmer temperatures have dramatically increased the beetles’ numbers, allowing them to move upwards to attack the whitebark pine.

And whitebark pines are slow to reproduce; they can take 75 years of growth before they sprout their first pine cone.

Blister rust is an invasive disease thought to have arrived in North America around 1900 from France with imported eastern white pine seedlings. The fungus kills by girdling branches on infected trees.

Concerns over the fate of whitebark pines are not new. Back in February 1991 the Fish and Wildlife Service was petitioned by the Great Bear Foundation of Missoula, Montana, to list the whitebark pine under the act. The foundation cited the same underlying reasons that the agency now is saying pose threats to the species: impacts from mountain pine beetles and white pine blister rust.

There also are concerns that the loss of whitebark pines will lead to the loss of Clark's nutcrackers. The birds, a member of the crow family, feast on whitebark pine seeds and have a habit of stashing many seeds -- some say thousands -- for later use. Of course, sometimes the birds don't recall where they buried the seeds, which then can germinate and sprout if they're not discovered by squirrels, chipmunks, or even grizzly bears.

According to the Fish and Wildlife Service, providing ESA protections to whitebark pine will boost new and ongoing research efforts to conserve the species, including future developments in combatting white pine blister rust. The protections for whitebark pine also make it illegal to remove, possess, or damage the tree on federal lands, or to engage in interstate or foreign commerce, including the prohibition of importing or exporting the tree. Unlike the prohibitions for federal lands, it remains legal to remove or possess whitebark pine on non-federal lands per the ESA, as long as those activities are otherwise allowed under state law. 

“We have the tools and capability to make populations more resilient to these threats. Given the scale of this effort, we are approaching restoration both collaboratively and strategically," said Diana Tomback, Whitebark Pine Ecosystem Foundation policy and outreach coordinator and professor of integrative biology at the University of Colorado Denver. “One promising work in progress is the National Whitebark Pine Restoration Plan, a roadmap for restoration being developed collaboratively between the WPEF and American Forests, in consultation with the U.S. Forest Service, the National Park Service, Bureau of Land Management, and several Northwestern tribes.” 

The FWS is not designating critical habitat for this species as part of the listing because habitat loss is not a threat to the species’ continued survival; disease from white pine blister rust is the primary threat.

Previous Traveler stories about whitebark pines:

Declines In Whitebark Pine Could Prompt Declines Of Clark's Nutcracker In Parks

Is Climate Change Driving A New Forest Regimen in the Greater Yellowstone Ecosystem?

Plan Crafted To Address Threats To Whitebark Pine Forests in Greater Yellowstone Ecosystem

Whitebark Pine Trees In Crater Lake National Park Under Attack From Blister Rust, Pine Beetles

Parks Canada Striving To Help Whitebark Pines Avoid Extinction

Research Shows Steady Decline In Snowfall At Yellowstone National Park

Report Lists 10 U.S. Ecosystems Whose Species Are Most-Threatened By Climate Change