DUPUYER – Even the living whitebark pine trees look tragic.
Each living tree points gnarled limbs at 10 dead fellows on this mountain pass in the Bob Marshall Wilderness. They bend and twist the way the wind shrieks along the Continental Divide, implying a mix of pain and defiance. They adapted to grow on the most hostile ground in Montana. But they’re failing.
Diana Six calls them “ghost forests.” At the edge of the tree line, beyond where the Ponderosa pine and spruce and alpine fir can survive, the whitebark pine used to rule. The University of Montana forest entomologist seeks them out on the slopes of Ch-paa-qn Mountain west of Missoula, in the Beaverhead Mountains above the Big Hole Valley, and the high ridges of the Bob Marshall. Her search gets harder every year.
Blister rust, an invasive fungus that followed western settlement of the Rocky Mountains, wiped out most of the whitebark stands in Glacier National Park and the Bob Marshall Wilderness Complex nearly a century ago. The Greater Yellowstone area kept its whitebarks far longer, until mountain pine beetles attacked the stands. Now nearly 95 percent of those trees are dead.
If they know it at all, most Montanans hear about whitebark pines in the debate over removing Yellowstone-area grizzly bears from federal Endangered Species Act protection. Delisting opponents based much of their argument on the recent collapse of whitebark groves in the Greater Yellowstone Ecosystem, and the subsequent loss of a major food source for bears.
Red squirrels collect the whitebark pinecones and stockpile them in middens. Grizzlies sniff out these stashes, which contain so much concentrated protein biologists half-jokingly measure them in “Big Mac equivalents” of several thousand calories.
Searching for replacement protein would move bears out of high-altitude isolation and into human-traveled lowlands, delisting opponents claim. That raises the odds of more conflicts and deaths.
The Rocky Mountains of Montana and Wyoming are the grizzly’s last real stronghold, with roughly 2,000 bears. The continental United States can’t afford to lose any to hunting or livestock defense, the opponents say.
Researchers for the Interagency Grizzly Bear Committee disagreed. Their study on bear food supplies found grizzlies were able to switch to other foods without risking their population numbers.
“It was an important food source in the Northern Continental Divide Ecosystem and it’s been gone for years, but the bears are doing well there,” said IGBC spokesman Gregg Losinski. “Our food synthesis report found that even if it’s available, bears didn’t always utilize it. Some love it, and others don’t care for it.”
So if the grizzlies may or may not care to eat them, and most of us will never climb high enough to see them, why care about the fate of an ice-age refugee?
Because around the base of each living whitebark grows what Six calls a “life island.” Creeping juniper and other plants shelter in the folds of its roots and build soil with their detritus. Pikas and marmots nibble the vegetation and shelter under the branches.
Those gnarly limbs spread outward so they catch snow like a baseball glove, instead of shedding it the way more cone-shaped pines do. That fortifies high-elevation snowpacks. In summer, meltwater coming from whitebark groves cools trout streams in valleys far below.
“If we lose these trees, it’s compounded even farther than the high-elevation ecosystem,” Six said. “It all cascades downhill.”
Whitebark pine is up for consideration as a threatened or endangered species because of loss of habitat due to climate change. Many discussions about saving whitebark pine consider transplanting trees to new, hospitable locations. That typically means northern latitudes in Canada that mimic the severe conditions of mountainsides in Montana.
Several long-running research programs seek ways to improve the tree’s resilience to drier, warmer conditions. Forest Service regional geneticist Mary Mahalovich recently informed the IGBC the tree may depend on a community of soil microbes or chemistry essential to its success. If correct, moving the tree north wouldn’t be enough. We’d have to move whole hillsides.
“And a whitebark pine takes 80 years to grow to maturity,” Six said. “We can’t breed them out of this problem. They take too long to reproduce.”
Deep in those ghost forests, Six looks for hope.
“Even when it looks like the entire area is dead, there’s always a few trees that are perfectly fine,” Six said. “There’s no evidence of failed attacks – no damage. The beetles didn’t miss these trees. They just didn’t go for them.”
Six would love to know why, but she’ll settle for which. It’ll take far too long to reveal what metabolic tricks those survivors used to fend off the fungus, discourage the insects and endure the drought.
Instead, she’s scanning whitebark DNA for a signature pattern amongst the survivors.
“It’s like a fingerprint,” Six said. “You don’t know if the person has blue eyes or likes art, but you know who it is.”
Finding that pattern has real urgency. Reforesting nursery-raised trees without first knowing which ones are the extra-hardy strains could even mean watering down the strong traits by flooding new groves with weak trees. Using “adaptive migration” transplants to northern latitudes might simply postpone the demise. It could also make whitepine into an exotic, invasive species in an ecosystem perfected for something else.
But advances in DNA have made the identification process faster and cheaper. Six recently received new support from the U.S. Geological Survey’s Climate Science Center to improve forest management tools with the genetic ID tactics.
“I used to think they were doomed,” Six said of the whitebark pine. “But there’s a little bit of evidence that some are climate-adaptive. I’ve been studying these since 1999, and when the beetles hit, I was going to give up. Now I think we’ve maybe got a shot.”