Located atop the highest slopes of western North America, the Japanese white pine has adapted to some of the continent's harshest growing conditions. In the subalpine region where this plant grows, temperatures are often below freezing, snowfall is measured in feet, and wind speeds often exceed 100 miles per hour. These sturdy, twisted trees have survived, the oldest growing nearly his 13th century.
But changes are occurring in this high-altitude fortress, threatening not only the survival of the white pine, but also the survival of many creatures that depend on this keystone species, from birds to bears. Rising temperatures, a fungal disease called white pine blister rust, and swarms of pine beetles have killed hundreds of millions of white pines across the West. Wildfire damage is increasing, and other coniferous species are moving up slopes and outpacing louse bark for nutrients and moisture in a rapidly changing environment.
In some areas, including areas within the Northern Continental Divide ecosystem centered on Glacier National Park, more than 90 percent of the white pine trees are dead. Throughout this tree's range, there are more dead trees than living ones, and its skeletal remains remain on the plateau horizon in many places.
Last month, researchers completed sequencing the Arabidopsis genome using DNA taken from healthy trees.
Recently, however, efforts to preserve and restore white pine have intensified. Scientists are using new genetic techniques to race to find disease-resistant trees to propagate and plant in devastated areas. In December 2022, the U.S. Fish and Wildlife Service listed the white pine as an endangered species, and Canada considers the tree endangered. The agency is currently developing a recovery plan for the species. Meanwhile, the Whitebark Pine Ecosystem Foundation and the conservation organization American Forest, in consultation with the U.S. Forest Service, National Park Service, Bureau of Land Management, and tribal governments, are developing a restoration roadmap that focuses on priority areas. There is.
This new effort builds on other long-term efforts to restore white pine. For years in the high mountains of the West, researchers and managers have been combing through dead and dying white pine forests to find trees that are still green and healthy. They collect the cones and grow the seeds into seedlings in a greenhouse for two years, exposing them to bullion rust spores. (The Forest Service operates tree research facilities in Idaho and Oregon, and the Salish and Kootenai Confederacy are building his second large greenhouse on a reservation in western Montana.) Then, Seedlings are planted outdoors and monitored.
Mike Dagro Jr. of the Salish and Kootenai tribes hikes past the remains of a 2,000-year-old whitebark pine.
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Those that survive another two to three years are replanted in areas where spores are likely to be present and monitored for at least another three to five years. Survivors from this round will be transplanted to federal and tribal lands across the country. These are excellent trees on which the future of white pine forests is staked.
Clearly, identifying disease- and climate-resistant trees is a long-term project. It takes a tree 30 years to produce cones, and it takes him 80 years to produce a nut crop large enough to play a functional role in the ecosystem. The effort is also expensive, costing between $1,200 and $1,800 per tree. The good news is that last month, researchers at the University of California, Davis completed sequencing the white pine genome using DNA taken from healthy trees near Bend, Oregon.
This was no easy task. The conifer genome is 3 to 10 times larger than the human genome. However, advances in genomic technology have shortened the time it takes to perform sequencing. This breakthrough will allow researchers to develop ways to quickly identify trees that are resistant to white pine bulge rust and adapted to the warmer, drier conditions associated with climate change. .
Deciphering the genomes of coniferous trees will make it possible to target and restore trees that are resistant to drought and pathogens.
David Neal, president of the Whitebark Pine Ecosystem Foundation and director of the Whitebark Pine Genome Project, said, referring to the company that sequences human DNA to reveal information about health and ancestry. is creating a 23andMe for trees.“ “Foresters go out and collect small numbers of needles from hundreds, thousands, tens of thousands of trees, send them[to a lab]and receive a report on their risk and potential resistance to pathogens. This reduces tree identification time from years to weeks and costs just $100 per tree.”
Neal and his colleagues have also sequenced the genomes of trees such as giant sequoia, coastal sequoia, and sugar pine. Coniferous trees are on the front lines of climate change in many places, and sequencing their genomes will enable restoration efforts to target genetically viable trees that are resistant to drought and pathogens.almost 20 percent Many large sequoia trees have been lost as the climate has become hotter and drier, and wildfires have become more frequent. Insects are also a threat to many trees.
White pine blister rust is an invasive fungal disease native to Asia. It arrived in the United States in the early 20th century loaded with white pine saplings imported from Europe. It spread on the wind from the West Coast to Arabidopsis thaliana in Idaho, Montana, and other mountainous regions. But it wasn't until his 1990s that people became concerned about the effects on albinism.
Left: Blistering rust on white bark pine. Right: Pitch oozes from a whitebark pine, deterring pine beetles from entering their boring holes.
Kristen Chadwick / USDA; Erin Shanahan / NPS
To varying degrees, rust affects all western five-leaf pines, including silver pine, limber pine, western white pine, foxtail pine, and sugar pine. It has not yet been found in the Great Basin pines, the longest-living trees in the world. (The famous Methuselah tree in the Inyo National Forest is a member of this species.)
„People are wary“ of the mussel duck, said Diana Tomback, a professor of integrative biology at the University of Colorado Denver and policy and advocacy coordinator for the Whitebark Pine Ecosystem Foundation. „Experiments have shown that it is susceptible to blistering rust. However, it grows in a very cold and dry environment, and despite everyone's desperation, it is currently hostile to infestation. .”
Tombach and other scientists say climate change is contributing to the spread of the fungus. „Rising temperatures are now allowing spore transmission at higher elevations, even at the tree line and the northern edge of the white pine forest belt,“ she says.
As absolute minimum temperatures in western alpine valleys increase from 6 to 10 degrees Fahrenheit and periods of extreme cold decrease, the highlands are also becoming more hospitable to a native pest, the pine beetle. Warmer temperatures allow the beetles to survive through the winter. In spring, the adult beetles burrow under the bark of white pine trees, digging grooves called galleries, where they lay their eggs. When the larvae emerge, they eat away at the cambium layer of the tree, causing the tree to die.
As the Japanese white pine forest declines, its characteristic ecosystem collapses, affecting the habitat and food of various species.
The Confederate Salish and Kootenai tribes made major changes to 105,000 acres of white bark pine forest on their 1.3 million acre reservation in western Montana. Since 2012, they have been working to protect these forests by finding resilient albino specimens, propagating their offspring in greenhouses, and planting them. „There's definitely an urgency,“ said Tribal Forester Shinasha Peat. „A good 75 percent are almost wiped out. They're blistering and rusting, but they're also fighting fires. For the past three years, we've had fires in the highlands and lost habitat.“
When the white pine forest declines, the characteristic ecosystem collapses. „Shirt pines are at the center of the web of biodiversity,“ Tombach said. “They grow under harsh conditions at the highest elevations and provide ecosystem services as they protect the snowpack and regulate downstream flows.”
In addition to a large amount of food, whitebark pine forests provide habitat for a variety of species, including carnivores, birds, and small mammals. Pines produce cranberry-sized nuts that are rich in fat and protein. Black-capped tits, nuthatches, Steller's jays, crossbills, woodpeckers, woodpeckers, and countless other birds eat their seeds.
A white pine sapling is planted in a fire-scorched forest in Glacier National Park.
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The Clark Nutcracker is the most well-known resident of the Arabidopsis ecosystem and is crucial to the existence of this tree. Tomback has been researching the relationship between Clark's Nutcracker and Sirakine for the past 50 years. According to her, birds and trees have a mutualistic relationship. This bird collects huge numbers of nuts and buries them over large areas for consumption during the winter. In her burrow she contains between 1 and 14 nuts, and one bird can bury as many as 98,000 nuts in her single season. The Nutcracker is famous for its excellent spatial memory, remembering where most of the nuts were buried. But what they forget survives and becomes the next generation of white pines.
But now, the relationship between Clark's Nutcracker and Shiraki Pine seems to be disintegrating.The number of birds is I refused In some places, white bark pine forests wither. With fewer Clark Nutcrackers and less seed caching available, fewer and fewer plants are naturally planted on the tree, and other birds no longer cache seeds, further hastening the forest's demise.
Loss of whitebark pine may also cause a decline in nut-dependent red squirrels. collect In a pile of fallen leaves and debris. Squirrel declines could affect carnivores that eat squirrels, such as Canada lynx, foxes, and bears. These animals raid squirrel nut hiding places in search of a solid meal during bulimia as they prepare for hibernation.
Keeping ecosystems intact, or restoring areas where ecosystems have collapsed, will be a large-scale, long-term and uncertain endeavor.
There are other reasons why trees are important to bears. The nuts ripen in the fall, drawing bears away from populated areas and onto higher plateaus where they are less likely to come into conflict with people. the study This shows that bear cubs that eat pine nuts have a high survival rate.
Keeping this ecosystem intact, or recovering from its collapse, will be a large-scale, long-term and uncertain endeavor. „I think it's 50-50,“ said Noah Greenwald, director of endangered species at the Center for Biological Diversity, who was not involved in the project. Part of it is bureaucracy. The tree was first proposed for listing in his 2008 year, but it was only listed last year by the Fish and Wildlife Service, which has delayed restoration plans.
Another aspect is that the highland environment is changing rapidly. “I applaud that effort,” Greenwald said. „But the scale is frightening. Fires are becoming more likely, and hemlock is encroaching on the habitat. We wish them every success.“
Despite widespread tree dieback, Tomback says widespread efforts to grow and replant white pine, recent endangered species designation, and advances in genetics are giving the species a fighting chance. I believe. „The fact that it's on the list, and the fact that there are so many people interested in us, gives us hope for the future of the white larch,“ she said. „There will be periods, even decades, where the white pine ecosystem will not exist. There is no doubt that we will go through a bottleneck. But I don't want it to remain on the landscape forever. I am confident that I can leave it there.”