Whitebark pine trees can live more than 1,000 years, but in just two decades more than a quarter of the trees that are a key food source for some grizzly bears have been killed by disease, climate change, wildfires and voracious beetles, government officials said as they announced federal protections Wednesday.
The U.S. Fish and Wildlife Service will designate whitebark pine as threatened with potential extinction, according to details obtained by The Associated Press. The belated acknowledgement of the tree’s severe decline will require officials to craft a recovery plan and pursue restoration work.
Whitebark pines are found at elevations up to 12,000 feet — conditions too harsh for most trees to survive. They are considered a “keystone” species other plants and animals depend on for survival, and their edible seeds are spread almost exclusively by a bird, the Clark’s nutcracker.
A nonnative fungus — white pine blister rust — has been killing whitebark pines for a century and they’ve been largely wiped out in areas. That includes the eastern edge of Yellowstone National Park, where seeds from the trees are a source of food for threatened grizzly bears.
More recently, the trees have proven vulnerable to bark beetles that have killed millions of acres of forest, and climate change that scientists say is responsible for more severe wildfire seasons.
The trees occur across 126,000 square miles of land in Wyoming, Montana, Idaho, Washington, Oregon, California, Nevada and western Canada.
Wildlife officials declined to designate which forest habitats are critical to the tree’s survival, stopping short of what some environmentalists argue is needed.
An estimated 88% of whitebark pine habitat is federally owned, with most of that area managed by the U.S. Forest Service.
Just over 50% of standing whitebark pine trees are dead, according to researchers. That includes about 25% that died in the past two decades, said Alexandra Kasdin with the U.S. Fish and Wildlife Service.
Despite the losses, remaining whitebark populations are resilient enough to withstand disease and other problems for decades, she said.
“We have found it is likely to become endangered with extinction in the foreseeable future, not that it is in danger of extinction now,” Kasdin said. “The species is still relatively widespread throughout its extensive range.”
Noah Greenwald with the Center for Biological Diversity said the decision not to designate critical habitat means whitebark stands could be harmed by construction of ski areas or other developments.
“How it’s going to be able to survive in a warming world isn’t totally known, so it would be prudent to identify places likely to be refuges and ensure they get protected,” Greenwald said.
The species is not commercially harvested, but California wildlife officials said timber harvests should nevertheless be considered a threat in areas where whitebark pine are intermingled with other trees.
A 2009 court ruling that restored protections for Yellowstone grizzly bears cited in part the tree’s decline, although government studies later concluded the grizzlies could find other things to eat.
That has complicated government efforts to declare grizzlies in the Yellowstone area as a recovered species that no longer needs federal protection. Grizzlies raid caches of whitebark pine cones that are hidden by squirrels and devour the seeds within the cones to fatten up for winter.