The Death of Ancient Trees: How to Continue the Genes of Great Ancient Trees
n 2005, several centuries-old ponderosa pines died suddenly in a forest I owned on about 15 acres in the northern Rocky Mountains of Montana. I soon discovered that they were killed by mountain pine beetles, deadly killers the size of the eraser end of a pencil that burrow through trees.
The following year, the number of dead trees increased exponentially. I feel powerless and sad to see these huge, towering trees disappearing around me, and there is nothing I can do to stop them from dying.
While native insects are the direct cause, the indirect cause of tree death in my hometown and throughout the Rocky Mountains is that winters no longer get cold. When I first moved to Montana in the late 1970s, winter temperatures were typically minus 34 degrees Celsius, sometimes dipping below minus 40 degrees for weeks at a time. The coldest temperature ever recorded in Montana was minus 57 degrees Celsius. Today, winter minimums rarely drop below around -18 degrees Celsius. Even if there is, it is only a day or two. This low temperature is not enough to kill pine beetles that are naturally frost tolerant.
Within three years, over 90% of the trees in my forest were dead. We hired loggers to fell the tree and truck it to a factory where it was pulped and made into fiberboard.
It's not just happening in Montana. Trees are dying across western North America. In 2006 and 2007, British Columbia lost 80% of its mature pine trees, turning from a carbon sink to a carbon source. Throughout the West, trees continue to die; a few years ago, 129 million trees died in California.
Seeing my forest die has piqued my interest in figuring out what's going on with these trees. In Montana and around the globe, I embarked on a 20-year investigation into the life and death of trees and forests.
Trees keep our water clean, our climate pleasant, wood for buildings, and a food source for humans and the animals we eat. They're even related to stars in some way. However, surprisingly little is known about what they do.
We also lack knowledge about the genetics of trees: especially the effect on the gene pool of the largest and strongest trees that have been felled over centuries. We also don't know how the trees that survive will fare in a hotter, drier world.
However, in the past few years, scientists have begun to study the importance of ancient tree genes, and there is growing evidence that ancient tree genes will play a key role in forests. The research follows a seemingly prescient attempt by a group of tree enthusiasts to plant these giant tree species in order to preserve ancient DNA they call the "library of lifeCraig D Allen spends most of his time observing forest death. His desire to understand how trees are dying due to climate change has earned him the nickname "Tree Coroner". Despite his recent retirement from the US Geological Survey, he is now busier than ever researching the crisis in the world's forests, and is an adjunct professor of ecology at the University of New Mexico.
Years ago today, I walked with him through groves of dying young pine forests near Santa Fe that had been killed by prolonged drought and heat. When I met him again recently, he told me that global deforestation is accelerating.
Allen's research team has meticulously revealed the impact of climate change on the world's ancient forests -- forests that live at least a few hundred years, and which we all love. It's a complex subject, but Allen points out that research papers published over the past decade have summarized the dire effects of a warming planet on these ecosystems.
One, a 2012 paper Allen co-authored, combined tree-ring data, climate records and future climate projections for the American Southwest. Future megadroughts triggered by climate change could have devastating effects on forests in the region, the study found. The crux of the matter is that while air temperature rises linearly, the atmosphere's ability to hold moisture increases exponentially. That means the atmosphere is getting drier at an alarming rate, with drought rapidly reducing moisture in soil, trees and other plants.
In 2012, a team of Australian researchers published a second study, collecting data on hundreds of species of trees—about the path water takes within a tree from its roots to its canopy. The study found that intensified droughts are draining water from forests at an even faster rate, and in many places trees can no longer keep up with the increased water stress, leading to symptoms akin to embolisms.
A third study, published in 2015, looked at the adaptation of trees to drought around the world. Allen told me, “From Arizona and Algeria to Alberta and Argentina, every major forest tree, wet or dry, is reported to be Drought, all dying in historically rare ways."
Because a warming atmosphere can hold more precipitation, in some places that are both warm and humid, some The forest is growing really well, better than ever. But in hot and dry regions, the number of dead trees is also increasing. "Climate extremes kill trees," Allen said. "It's getting worse." Unprecedented extreme events are happening, such as temperatures hitting 49 degrees Celsius in British Columbia this summer.
Bearing the brunt of this changing world are older trees, many of which are more than 200 feet (61 meters) tall, or even 300 feet (91 meters).
“One of the risks to giant old trees is that they become very expensive to survive,” Hammond said. They need more water and more energy to pump water up the canopy. They can be damaged by drought, or severely weakened, falling prey to insects, disease or fire.
More frequent heat and drought also means less time for trees to recover. "After the drought is over and the trees are well watered again, they have a chance to regrow," said Anna Trugman, an assistant professor at the University of California in Santa Barbara who studies the effects of climate change on forests. grow, restore some damaged organs. But if the drought becomes more frequent and continuous, it leads to a longer-term decline in the quality of growth because they cannot recover.”
Those tall old trees basically have no resistance.
That's a problem because not only are these ancient trees huge, old, and awesome, but they're also vital for storing carbon to keep the world from accelerating warming. The largest 1% of trees store 50% of the carbon in the forest.A dire future for trees is yet to come, even as we strive to learn more about them. Suzanne Simard, an ecologist at the University of British Columbia, has discovered that trees are connected, that through roots and fungi, they communicate with each other and transfer resources. Researcher Diana Beresford Kroeger believes trees release large amounts of aerosols such as terpenes and limonene, which are natural antibiotics, antivirals and chemopreventives that help keep The health of nature, including humans.
Hammond and Allen predict a mass extinction of the world's largest trees and forests. Research shows that today's forests are very different from those in history, partly because of hotter and drier environments. Hammond said: “Forests are getting shorter and younger, and dominant species are shifting. Trees are here to stay and will be with us for a long time. But they will change.”
So what can we do? Reducing carbon dioxide emissions to slow climate warming is a top priority, but it may not get better for decades. In some places, deforestation or periodic fires can help. Some forests have 800-1000 trees per acre, which means intense competition for water; a healthy forest should have one-tenth that. Also, some redwood groves are being considered for irrigation.
In addition, attempts have been made to replicate the largest tree species in existence
As early as the 1990s, a father and son in rural northern Michigan planned to use vegetative propagation of cuttings to grow one of the largest tree species in the United States.
It's a program called the Champion Tree Project. David Milarch is a fourth-generation shade tree farmer. He looked at the largest tree species in the National Register of Big Trees maintained by American Forests, a Washington, DC-based nonprofit. He and his son Jared drove to the champion tree and asked its owner if they could take some cuttings.
They unloaded the ladder from the back of the pickup truck, and Jared climbed up a tree to pick a few twigs. Cuttings are sent to nurseries to grow copies. Mirage and his son will then plant the cuttings in different settings, such as cemeteries or parks, in what Mirage calls "living herbariums." The idea is to preserve the genetics of 800, 2,000 or 5,000-year-old trees around the world in case the original tree dies.
“The genes of the big trees are disappearing,” he told me when I reported on the program in 2001. "Someone had to take cuttings and keep them and document them. No one knew what that meant at the time."
Mirage's project focuses on America's oldest and most iconic tree species: the redwood. More than 20 years ago, I watched his team climb some of the largest trees in the world so that they could cut needles from high up, the best material for cuttings. These include the majestic Waterfall Tree, a giant sequoia on a privately owned central California forest that is the whale of a species, with orange-red bark that dwarfs humans. A photo of this tree is on the cover of my book, which tells the story of an arborist who has gone to great lengths to grow the world's largest tree species from cuttings and multiply it around the globe.
I moved on to other things, but in the summer of 2021, my 20 years of experience with Mirage came to the fore again. Wildfires have swept through California's famous redwood forests, killing one in five trees. The waterfall tree was one of them - charred.
Long thought to be indestructible, these trees have been dying in increasing numbers in recent years. "What we're seeing now is wildfires that can burn huge numbers of giant sequoias," said Christy Brigham, director of resource management and science for Sequoia and Kings Canyon National Parks. We have 100 years of experience fighting wildfires, but climate change making the environment hotter and drier is making things worse."
The disappearance of giant sequoia populations is also a concern. "We don't know what might be lost," Brigham said. "But we're talking about a species that's already at risk of extinction, and only 78 forests have it. Now the fires have destroyed 19% of the adult trees. In the In one grove, 80 percent of the saplings were destroyed."Mirage's organization, the Archangel Ancient Tree Archive, is still propagating trees from cuttings, and they're heading to California to find seeds in hopes of growing a "lost" grove of redwoods, Mirage. Luckey thinks the size of the redwood grove could be a record.
They are still planting groves. “We planted 75 sequoias from cuttings in San Francisco’s Presdio,” he told me recently, referring to a former military base, the San Francisco Presidio, that has been turned into a park. "As part of the transplant, we've planted redwoods in 41 cities in the Puget Sound area."The philosophy of the Archangel Ancient Tree Archive is that while these 2,000-year-old trees cannot move, their genes can. While planting cuttings to create a new forest didn't save the species, it did preserve their genetics. In the fall of 2021, the group will be planting cuttings in its own greenhouses, planting waterfall trees and other species in places where forests have been destroyed by fire this summer, and farther north where, in a warmer future, they may It is more conducive to the growth of sequoia. "A 2,000-year-old tree needs to be preserved," Mirage said.
The importance of ancient tree genes has inspired composer and music producer Timothy Smit to learn from the Archangel Forty-nine cloned sequoias were bred from the collection of the Ancient Tree Archives, a program that includes thousands of plants from around the world. He recently told me, “These saplings came from 3 feet (0.9 meters) tall and are now 15 feet (4.6 meters) tall. They survived.”
After two decades of breeding from cuttings, a study published this year confirmed Mirage's method of preserving the genes of ancient trees. The study concluded that ancient trees fundamentally contribute to genetic diversity, thereby contributing to the long-term resilience and adaptive capacity of surrounding forests.
"These ancient trees represent individuals who have survived a long history," said study co-author Chuck Cannon, director of Morton Arboretum's Center for Tree Science in Illinois. "They contain specialized combinations of genes that can span centuries and provide beneficial genes in extreme environments that occur only once in hundreds of years. They are critical to the long-term resilience of forests."
Despite this, Cannon said, little research has been done on the genes of ancient trees, which are both rare and difficult to identify. That's why he thinks it's so important for the Archangel Ancient Tree Archive to clone ancient trees.
"Learning to propagate this living material could be invaluable so that we don't lose the unique combination of genes these trees represent," he said. In essence, creating these ancient gene forests could help other forests increase their genetic diversity , and adapt to a rapidly changing world.
As I walk through my tree farm these days, I am heartened to see the descendants of the dead pines return. Although the ancient trees that once stood are gone, the mountains and forests have not disappeared, at least not yet.
However, I no longer take forests and trees for granted. They are increasingly vulnerable, and the loss of them would be immeasurable
