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Wednesday, February 8, 2023

A Bold Plan to Save the Last Whitebark Pines

Melissa Jenkins usually doesn't take pictures on hikes in Montana's Whitefish Range. Here, the whitebark pine that she works to restore has been so decimated by a fungus that gray skeletal ghost forests reign, haunting symbols of a once widespread species. But last summer, she paused to snap a shot of survivors flanking the trail, ragged but defiant. "It felt like walking through soldiers standing guard even though they had little left to give to the battle," she recalls. "Walking through ghost forests is somber, because you can envision what once was, and you aren’t sure if it will ever be that way again."

For 30 years, Jenkins has been working to save these trees, which grow where no other trees dare. They grow in sterile soils on exposed slopes, marking the tree line, and they provide habitat and forage for birds and bears where there is nothing else. “It represents wildness. It represents my passion for the outdoors,” Jenkins says. “It's a keystone species so important to high-elevation ecosystems. Man introduced the blister rust that has decimated this species, and I feel like it’s our responsibility to try and help restore the species.”

Jenkins is a founding member of the Whitebark Pine Ecosystem Foundation, and she retired from the US Forest Service last summer. Retirement changed little. She became a federal contractor spearheading a restoration strategy for the Crown of the Continent Ecosystem, which covers 18 million acres straddling the Continental Divide in northern Montana and southern Canada.

Today, there are more dead whitebark pines in the United States than live ones, according to the Forest Service. In some areas, including northwest Montana, where Jenkins is based, up to 90 percent of the whitebark have perished. In Canada, the trees have been listed as endangered since 2012. They have fallen prey to the ravages of blister rust infection and pine beetle infestation, exacerbated by climate change in recent decades.

The range of whitebark pines extends north to British Columbia, south to northern Nevada, west to the Pacific Northwest, and east to Wyoming, growing at up to 12,000 feet, their trunks often contorted by harsh winds. They are a keystone species critical to ecosystem health. Their high-protein, high-calorie seeds (1 gram has between 5,000 and 7,700 calories) are important food for more than 100 species, including grizzly bears, birds, and squirrels. They are among the first to regenerate after fires, a "nurse tree," providing shade and shelter from the wind for smaller, slow-growing species. And their candelabra canopy slows snowmelt, helping to regulate runoff and mitigate spring flooding and summer drought, important to drinking and agricultural water supplies. Without whitebarks, the West faces a more perilous future.

For a decade, environmental groups have unsuccessfully pushed for the whitebark pine, Pinus albicaulis, to be protected under the Endangered Species Act in the US. In late November, the US Fish and Wildlife Service proposed giving it threatened species status. Jenkins and others working to resurrect the species hope that the new attention will bolster funding for innovative answers: combining old-fashioned seed collection and grafting techniques with modern strategies to identify trees resilient to the fungus, collect their seeds, and then plant seedlings in places where they will thrive.

"It's one of the most rigorous, forward-thinking forest restoration efforts in the country. Geneticists, field biologists, field foresters, and nursery staff are engaged in this and thinking through what's needed,” says Eric Sprague, vice president of forest restoration for American Forests, a nonprofit that has partnered with the Forest Service and the Whitebark Pine Ecosystem Foundation to help plant 700,000 trees so far.

Whitebark pine regenerates almost exclusively thanks to the Clark's nutcracker, a gray and black bird with a long, sharp-tipped bill. Nutcrackers are foresters with wings, harvesting ivory seeds from cones, storing them in a throat pouch, and then flying as far as 20 miles away to bury them in caches of four or five seeds to get them through the winter. Each bird hides tens of thousands of seeds in thousands of locations, and, naturally, they forget where some of them are, essentially planting new whitebark colonies. But as the tree continues to decline across its range, fewer seeds are borne by nutcrackers, reducing the species' regeneration. 

In recent years, they have been felled mainly by a fatal fungus introduced to North America more than a century ago by pines imported from Europe. "White pine blister rust is the existential threat," says Diana Tomback, a professor of integrative biology at the University of Colorado, Denver, and a founder of the Whitebark Pine Ecosystem Foundation who has studied the trees for four decades. "It is spread by wind and it cannot be contained. The foundation of restoration is finding these resistant individuals."

Rust spores from infected currant or gooseberry shrubs enter through whitebark needles and move down to the branch, where a canker develops as the infection works its way to the trunk, preventing the tree from taking up water and nutrients. A few trees, perhaps only 5 percent in some areas, have a natural resistance.

People’s effort to do the work of birds begins when foresters look for those specimens, nominees for what they call mother trees, which may yield offspring genetically resistant to the fungus. In July, climbers cage the cones of those trees to foil the Clark’s nutcracker. In September, they return to collect them. The cones are harvested for seeds, which are grown for two years in a Forest Service nursery before being exposed to the rust spore by laying infected leaves over them to test whether they are resistant. They are then monitored for five years. Why? Just because trees appear rust-resistant doesn't mean they are. The mother tree nominee may just have gotten lucky and escaped infection. "At a minimum, it's eight years between when you collect the seed and when you find out how resistant it is," Jenkins says.

But cone collecting is expensive and requires taking the long view. Seedlings cost $2.15 each, including the cost to collect seeds and grow them in a nursery. Restoring an acre runs about $800. Tomback says the whitebark range encompasses about 55 million acres in the United States, and the national restoration plan’s goal is to plant between 11 and 16 million acres of them within 15 years. Whitebarks don't begin producing cones with seeds until their fourth or fifth decade and may not bear them in meaningful numbers until they reach the century mark (some live 1,000 years or more). 

So in an effort to trick time, some seedlings at the nurseries are grafted with a small cone-bearing branch from the top of a mother tree. These have yielded young "conelets" within a year, but they will not be pollinated until the trees are large enough to support mature cones. If successful, though, the effort could eliminate decades of waiting for seeds. "These orchards are investments for the future to make it easier to gather seeds and grow seedlings," Tomback says. "But we need another technology."

That technology is gene sequencing. The Whitebark Pine Ecosystem Foundation is raising funds for the project, which could identify fungus-resistant trees by analyzing a small amount of needle tissue. “We hope by identifying the genes which can confer resistance, we can shortcut the process for figuring out which trees are resistant,” Tomback says.

In the meantime, the pilot restoration strategy for the Flathead National Forest, Glacier National Park, and the Confederated Salish and Kootenai tribal lands in Montana has identified places most likely to be successful for the limited seedlings and funding available. Sprague points to the Repairing Existing Public Land by Adding Necessary Trees (REPLANT) Act, that had bipartisan backing in Congress to fund $120 million more annually, as one step towards the needed support. The bill, pushed by forestry associations, hunting groups, and outdoor recreation groups, passed the House but did not get a vote in the lame-duck Senate session. It will be reintroduced in the new Congress.

So far, restoration has been slow. In the Flathead National Forest, for example, between 30 and 125 acres have been planted annually in recent years, a fraction of what’s necessary, Jenkins says. "It's going to take a long time," she says. "It's complicated. The more we learn, the more we realize what we don't know. But we've got a really good start."

In the past, she questioned whether the tree she considers a companion on those high-elevation hikes would survive. Now she has hope. "It depends on how much humans want to invest," Jenkins says. "We can definitely restore this species. There's no doubt in my mind."

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