In California, a Race to Save the World’s Largest Trees From Megafires

When the Washburn Fire burned through part of Yosemite’s iconic Mariposa Grove in July, photos of its famed giant sequoias steeped in smoke and surrounded by automated sprinklers to shelter them from the flames shocked viewers around the globe. 

Less than a year earlier, similar photos showed the trunk of the sequoia known as General Sherman, the world’s largest tree, wrapped in a tinfoil-like material to repel the flames of the KNP Complex Fire. Yet, while those efforts helped save the celebrity trees from the infernos, the annihilation elsewhere in California’s Sierra Nevada mountains is difficult to grasp: The U.S. Forest Service estimates that, in 2020 and 2021 alone, wildfires killed 13 percent to 19 percent of the world’s giant sequoias. 

“Those are crisis numbers,” said Tim Borden, the sequoia restoration and stewardship manager at Save the Redwoods League, an advocacy nonprofit stewarding several sequoia groves that have been deeply impacted by high-severity fires. “The lights are flashing red.”

While climate is one driver of the growing size and intensity of the megafires decimating the world’s largest trees, it’s only part of the picture.

“Part of this is caused by how our forests have changed because of management decisions that were well intentioned at the time, but not really fully known,” Borden said.

For a century, federal and state agencies worked to extinguish all natural wildfires and prohibited Native people in the region from lighting the blazes they used to manage the land, which led forests to grow far thicker with trees that could fuel fires. Borden estimates that the Sierras are now home to three times more trees than when they were being stewarded by Indigenous communities. And more than 100 million of those trees had died due to drought by 2016. 

Now, on top of that heavier load of fuel “you have all the effects of climate change—of a drier, hotter environment,” he said. “It’s creating this perfect storm in sequoia groves.”

Those flashing red lights have prompted a new level of collaboration among the 11 groups that steward some of the world’s largest and oldest trees—federal and state agencies, a nonprofit, a university and a tribe. They’re also catalyzing a piece of federal legislation that could put more resources toward prescribed burning and other forms of active forest management, in hopes of speeding that work over the next decade. 

But the bill is controversial with some environmental groups, which worry that it undermines important environmental laws, could imperil endangered species and sets a dangerous precedent. Still, members of the coalition stress that it is essential to work fast at a time when the climate crisis—and the West’s “forever fire season”—has made it especially challenging to find safe windows for prescribed burning, and the political and social will to use fire to fight fire has yet to catch up to the urgency at hand.

Still, all sides agree that preventing megafires from continuing to decimate sequoia groves requires foresters and firefighters to intentionally set those forests on fire more often. And an increasingly recognized key to that work is supporting the one federally recognized tribe that still cares for five of the sequoia groves as it finds its way back to its long-outlawed tradition of burning the forests. 

Bigger, Hotter, Faster Fires

Giant sequoias are the size of small skyscrapers. As with the Grand Canyon or Niagara Falls, standing beside them reminds us of our relative insignificance in the vast expanse that is the natural word. It’s part of what attracts nearly 2 million people to Sequoia and Kings Canyon National Parks every year. And it’s what kept news watchers’ eyes glued to the firefighters protecting the Mariposa Grove this summer. 

“I really appreciate the deep love and connection that so many people around the world have for these trees because of their immense size and age,” said Christy Brigham, chief of resources management and science for Sequoia and Kings Canyon National Parks, home to around half of the existing groves of the iconic trees. “And a lot of people have been devastated by the wildfire’s effects; I know I have been.” 

Wildfire’s effects on sequoias, in fact, have historically been positive. Giant sequoias evolved to live with the lightning-ignited wildfires and Indigenous prescribed burns that regularly traveled across the floors of their groves. Bark that can be two feet thick shields their trunks from fire and bottom branches that tend to fall off as the trees grow leave their lowest limbs out of reach of the flames. The giant trees also depend on fire to release the seeds inside their cones and to remove competing trees that might deprive them of the ample sunlight they need to flourish.

Scientists now estimate that giant sequoia groves used to experience an average of 31 fires per century—either through Indigenous burns or wildfires. Those blazes would consume smaller trees from around the feet of the giants and give new sequoias a place to take root.

But the fires around the sequoias are changing. Scientists first noticed the impacts of increasingly severe conflagrations after the Rough Fire in 2015. Then, three massive wildfires—the 2020 Castle Fire and the 2021 Windy and KNP Complex fires—swept through the region in an 18-month period.

The growing number of dead and dried-out trees below the giants allowed fires to ignite easier and burn hotter, while the increasing density and height of the woods around the sequoias provided ladder fuels that allowed flames to climb into the forest canopy. 

A recent study looking at the high-intensity fires that took place in the Sierras from 2015 to 2017 found that numerous sequoias suffered from severe burn scars and many of their crowns went up in flames, ultimately leading to their deaths. In areas where fires burned at high severity, 84 percent of the towering trees died—a proportion that was essentially unheard of just a few years earlier.

Brigham and members of Save the Redwoods League suspected the long-established pattern of fire in the sequoia groves was shifting. Then the 2020 Castle Fire burned a dozen sequoia groves in the national park alone.

“A handful of them burned way outside what we call the natural range of variation,” Brigham said. The National Park Service estimated that between 7,500 to 10,600 giant sequoias were killed in that one fire.

“Some part of my brain was like, ‘There is no possible way that fire could have gotten up into those canopies and torched those trees,’” said Linnea Hardlund, a wildland firefighter and Save the Redwoods League’s forest ecologist. “‘They’re so tall!’” But when she entered the grove shortly after the fire, “it completely took my breath away, in a similar but very different way from the first time I saw a giant sequoia. And it rocked the foundation of knowledge I had started building from field experience.” 

In July 2021, the existential threat to sequoias began to come into focus across the forestry world. The National Park Service, the U.S. Forest Service and the Bureau of Land Management, which oversee much of the land where the trees reside—joined eight other entities responsible for stewarding groves of the giant trees, including the State of California, the University of California, Berkeley and the Tule River Indian Tribe to form the Giant Sequoia Lands Coalition to respond to the disaster. 

Among the numerous politicians and scientists who toured the charred groves in Sequoia National Forest were members of Congress led by House Minority Leader Kevin McCarthy (R-Calif.).

“After seeing the Giant Sequoias first-hand and understanding the damage fires have caused to our communities, it’s clear there is an urgent need to address this crisis through fire prevention and better forest management,” McCarthy said.

Bruce Westerman (R-Ark.), a ranking member of the House Committee on Natural Resources, called the devastation he witnessed “a clear sign that we have to dramatically and rapidly change our strategy to prevent any more loss.”

In late June, McCarthy and 44 bipartisan co-sponsors introduced the Save Our Sequoias Act, which—if passed—would declare the situation an emergency, assess the damage for Congress, codify the existence of the Sequoia Land Coalition and provide a pathway for federal funding to “support the implementation of hazardous fuels reduction treatments in and around Giant Sequoia groves,” which includes a grant program for forest stewards, among other things. 

The bill would allow the members of the coalition, scientists and land managers to carry out “special projects” to protect the sequoias as they see fit, without undertaking reviews of the potential impacts of the proposed work that are typically required under National Environmental Policy Act (NEPA), the National Historic Preservation Act (NHPA) or the Endangered Species Act (ESA). But those shortcuts so alarmed some critics that more than 80 environmental groups, including the Center for Biological Diversity, Earthjustice and the Natural Resources Defense Council—organizations that would normally support government efforts to protect significant stands of trees—penned a public letter opposing the bill. The groups expressed concern about “rushed and poorly planned logging projects,” harm to imperiled species and a lack of transparency at a time when conservative lawmakers have often sought to weaken NEPA and other environmental review processes.   

“Those environmental laws were put into place to ensure that when federal agencies like the Forest Service undertake land management decisions, they do that in a way that not only follows the best available science, but also conserves listed species, and provides a public opportunity to comment and be involved in those decisions,” said Susan Jane Brown, the wildlands program director and a staff attorney with the Western Environmental Law Center, who spoke for the groups opposing the bill. “In our view, even though the purpose of the legislation is a good one—we want to protect sequoias—we don’t believe that waiving environmental laws is necessary in order to get there.” 

Earth Justice’s Blaine Miller-McCafee called the bill a “Trojan horse to diminish important environmental reviews and cut science and communities out of the decision-making process.”

Other environmental groups, such as the Nature Conservancy, are behind the bill. Save the Redwoods League, which wants to see 2,000 acres treated in the most at-risk groves before the 2023 fire season, supports the bill, and even contributed language to it. Sam Hodder, the League’s president, said that the act provides what the stewards on the ground say they need. “The specifics don’t in any way change those bedrock environmental laws,” he adds. “They exercise the flexibility that’s built into those laws to allow stewardship and response to emergency.” 

Urgent action, unhindered by Environmental Impacts Statements and other preliminary reviews required by NEPA, ESA and NHPA, is necessary not only to save the sequoias, but the many other species that are dependent on their groves, Hodder argues. 

“I think first and foremost we are taking those species into account to ensure that their habitat doesn’t turn into a moonscape,” he said. “The landscape of the high-intensity fires after the fact is heartbreaking and devastating and for the protected species there is no respite, and there is no habitat.” 

In August, the White House announced separately that the U.S. Forest Service would conduct emergency fuels treatments “as expeditiously as possible” in 12 of the giant sequoia groves it stewards. But that came on the heels of the Forest Service pausing all prescribed burns on its lands for 90 days after two burns that escaped control merged into the largest wildfire in New Mexico history. A few months before that incident, it had announced its intention to steeply increase the amount of land it would treat with prescribed fires. The agency’s whipsawing has left some foresters and firefighters worried that burns that go wrong even far from California could slow the desperately needed treatment of the sequoia groves.

Reclaiming Tradition to Ensure the Future of Sequoia Groves 

One group hoping to use fire to save the sequoias would not be so vulnerable to shifts in the political winds, if it can just redevelop their capacity to do the work. And for those people, who live at the edge of those burned moonscapes, the urgency described in the bill is far from theoretical. On the Tule River Indian Reservation, located 8,000 feet to the south of Sequoia and Kings Canyon National Parks, the hillsides are a patchwork of life and death. 

In the huge swaths of forest blackened and emptied by the Windy and KNP Complex fires, a small crew of tribal members work through the spring and summer to clear and thin branches, salvaging and selling what timber they can to fund their work. The tribe has joined the Sequoia Lands Coalition and its members plan to apply for grants through the Department of the Interior and, if it passes, the Save our Sequoias Act to subsidize their forest restoration work in winter. It would also allow them to rekindle their tradition of cultural burning—intentionally igniting fires in the five sequoia groves they steward on the reservation to reduce the excess accumulation of woody fuels and improve the habitat for plants and animals the tribe depends on.

Harold Santos, a Tule River tribal council member, remembers helping his father with cultural burns in the 1970s. “My dad was the range manager up here. When we were little, we always had to go to work with him,” said Santos. “I always thought they were burning just to burn. But they did it for the plants. Because [after the regrowth] that’s where they picked their red bud and elderberry and stuff like that.”

Those critical plants for the tribe’s traditional foods and baskets fell into decline when the burns came to an end decades ago as state and federal policies prohibited such uses of fire by the tribes in the region.

“It’s funny that there’s a term for it: cultural burning,” said William Garfield, another member of the tribal council. “That’s just what people always did here to take care of the forests.”

For Santos, Garfield and the roughly 2,500-person tribe they represent, the choice to get involved with the Sequoia Lands Coalition was part of a larger decision to take a more collaborative approach to protecting the natural resources on the reservation. Last year, they hosted a meeting that brought representatives from all the organizations in the coalition to the reservation. 

Santos is optimistic that this collaborative approach—after years in which the tribe took a more protective, separatist stance—will better staunch the devastation in the sequoia groves. “We’re going to be able to protect the groves better with everybody getting together, sharing ideas and learning about what other people are doing,” he said.

The fires are just one in a range of climate change impacts hitting the tribe. Just a decade ago, the Tule River provided ample water for community members, the cattle they graze on the reservation and the 400 wild horses that roam the property. Now the river is shallow in summer. By mid-July, nearly all of the creeks had dwindled to a trickle. The tribe’s spring wildflower festival—once an annual occurrence—has been called off for the last three years because there are now so few blooms on the reservation.

“The bark on the sequoias, it was never completely dry,” said Santos. “But now it’s so dry, it just catches like that.”

And before the recent wildfires, the federal forest land that borders the reservation hadn’t seen fire in around a century, allowing an accumulation of timber that made it particularly susceptible to burning big and hot enough to ignite the once fire-resistant giants.

Carlos Desoto, a member of the tribe’s wildland fire department and the tribe’s new cultural fire specialist, has spent the last several years studying prescribed burns, working with experts on the cultural importance of fire and connecting with other tribes in the region that are also looking to bring back cultural burning as a tool to respond to the growing climate crisis. 

“I’ve gone outside my job skills and what I thought I could do to try to protect our lands, all our trees, and our waterways a little bit better—and to try to keep our animals safe,” he said.

The hope, he said, is to reforest the slopes of the mountains at the back of the reservation and help support the new life that is returning—as it always has—in areas where the fires burned at a lower severity.

“The goal is to make this land look like it did when I was little so that two or more generations from now they get to see the same things,” said Desoto. 

Yet, like most firefighters in California, Desoto admits that the pace of the work over the last few years has been exhausting. That’s a challenge many in the Sequoia Lands Coalition hope to address—the need for an expanded workforce to prepare the forests for the wildfires of the future.

“We need frequent fire within these forests to maintain their health, to keep the forest low-density, and establish areas for giant sequoia regeneration,” said Brigham, the national park resource specialist.

The coalition is in the process of identifying the groves that need prescribed fire most urgently and others that need the thinning work—clearing trees and vegetation with axes, chainsaws and rakes—that often precedes those fires. In Kings Canyon and Sequoia National Parks, she said, the highly trafficked areas have seen regular prescribed fire for decades, but other less accessible groves are way behind.

“We have a whole bunch of other burns that we’re hoping to be able to execute if we get a window,” said Brigham. Some of those will bring fire to the groves for the first time in decades, if not a century, to reestablish the role of fire in maintaining the health of the landscape.

“We also have three groves [where] we just got funding to do restorative thinning because there’s too much fuel to introduce fire yet.” 

Hardlund, a firefighter from a family of firefighters, said expecting the crews that fight fires to show up for prescribed burning and other forest management work isn’t realistic given their already growing workloads. “It needs to be a different workforce, or we need to double our wildland firefighting workforce, or stagger crews by the seasons,” she said.

Some of this growth may be on its way. The Biden administration recently announced that several federal agencies are working to expand their capacity. The Bipartisan Infrastructure Law (BIL) also designates $600 million to increase pay and create new programs to support firefighter mental wellness and healthcare among other efforts. 

Shrinking Windows for Fighting Fire with Fire

Whether conducted by federal or state agencies, nonprofits or tribes, prescribed burns are notoriously difficult to plan and execute. The weather has to be just right, with temperature and humidity within specific ranges. Burns require enough wind to stoke a low-intensity fire and dissipate its smoke so that it doesn’t present air quality problems in nearby communities, but not so much that it could blow the flames out of control. Changes in those conditions can lead managers to cancel a burn, or shut it down after it has been ignited.

In May, an unusually late spring storm brought rain and snow to Calaveras Big Trees State Park, delaying the prescribed burn planned for the forest several times.

The morning it finally came together started with a briefing and a test burn.

“Everyone watches the small fire,” said Save the Redwoods League’s Borden, who was coordinating the effort. “If it behaves the way we want it to, the burn commences. If not, we all go home.”

On this day, the conditions were right, so they proceeded with the burn. A firing team moved slowly across the space using drip torches—spouts that extend from hand-held canisters filled with a mix of diesel and gasoline—to burn the ground in what are called “dots and strips” to ignite the low-growing foliage and pine needles in multiple places. Meanwhile, more than 50 other people, in a long chain of command, filled a variety of roles to ensure that as the blaze gradually built in intensity it also stayed within the designated burn area. Some guard specific trees to protect important species or prevent hazards, like fire-weakened trunks that could fall on the burn crew, from developing. Others stood at the ready to find and put out small spot fires that could pop up along the way. Still other crew members filled holding positions with hoses and fire trucks at the ready.

Over the preceding weeks, crews had cleared and dug a containment line around the quadrants they planned to set ablaze and removed plants that could have burned the shallow roots of the red-barked behemoths when they ignited. 

Occasionally one of the smaller trees would torch, sending flames toward the sky, but most of the fire rolled along the ground through grass, scrubby brush and the trunks of young dogwoods and other smaller trees that crowded between the giants. 

The burn took place in the park’s north grove to prioritize the area most popular with tourists. It’s home to a visitor’s center and an easy half-mile loop hike through a handful of monarch sequoias—the kings and queens of a stand of several hundred giants up to 2,000 years old. The south grove, a 20-minute drive away, is much larger and is home to more than 1,000 sequoias. Borden had hoped to burn that grove, as it had been recently deemed among those at the highest risk of damage from a high-severity fire. Instead, its burn was pushed to the fall.

On the second day of the four days planned for herding the flames through the grove, veteran burn boss Ben Jacobs compiled specialists’ observations of weather, fire behavior and the effects of the flames, and made the call to end the burn early. 

The disappointment on the scene was palpable, but extra caution was warranted. It had only been days since a wildfire erupted from the prescribed burns in New Mexico. 

But playing it safe with prescribed burns is a balancing act in which delays to avoid less-than-ideal conditions can leave a forest primed to burn big when the wildfire season is at its peak. California’s historic fire season was right around the corner and the window for preventative burns was rapidly closing. There was just one more planned in the sequoia territory—in the Giants Grove inside Kings Canyon and Sequoia National Parks—before summer weather made burns untenable. 

Indeed, the window for prescribed burns is getting smaller by the year. 

“In the winter, there’s snow. It’s hard to access,” said Joanna Nelson, director of science and conservation planning for Save the Redwoods League. “In the spring, there are often threatened and endangered species on the landscape, so it’s a limited operating period. In the summer, you often can’t burn if the state agency or the Forest Service has put a ban on burning. And so you have the fall—and these days that’s when wildfires are either starting or already burning. If it’s too dry outside, if the temperatures are too high, you can’t burn.”

All those rules are there for good reason, Nelson said, but she hopes the Save Our Sequoias Act provides more flexibility in place of blanket rules, so they can put more “good fire” on the ground faster. 

“To be able to send in a weather report that’s really specific to your area, to be able to adapt to conditions and microclimates and say, ‘Actually right here, where I am, it’s a good time to burn. And I need the approval to go ahead,’” she said. “That’s what we’re asking for, the ability to go faster.”

The League estimates that it will take $500 million over the next five years to conduct the necessary treatments on the land around the ancient trees. But Nelson stresses that the price tag is much more affordable than fighting wildfires, which cost California a total of $1.2 billion in 2021 and grows more expensive nearly every year. And that number is dwarfed by the astronomical cost of the destruction caused by wildfires in the state, which researchers at Stanford have estimated to be $10 billion a year in 2020.

As for those mountainous slopes that are already blackened by fire? Sequoia Lands Coalition members assessed the combined impacts of the Castle, KNP Complex and Windy fires and found a silver lining—especially in the places where those fires burned at a lower intensity. 

“Even though there was a lot of loss of giant sequoias, an uncomfortable amount of loss, once we moved past the grief, we have begun to really understand that these fires did a lot of good,” said Borden. “In the last three years, wildfires have treated more acres of sequoia groves than we could have possibly imagined doing in a decade plus.”

On the Tule River reservation, for instance, some of last year’s burn scars are already dotted with flowering elderberry bushes. And in the nearby sequoia grove that’s rebounding from the 2021 Windy Fire, an entire hillside is covered with a thick carpet of bright green sequoia seedlings—an unusual site that may inspire a rare flush of optimism in the charred landscape.

A single prescribed burn isn’t enough to transform a landscape, Borden stressed. That requires a series of treatments, and a repetition of the process that mimics the natural cycle of fire to get the land to a place where it can withstand blazes and rebound when they—inevitably—arrive.

The hope is ultimately to create a cultural shift that returns fire to its rightful place as a cyclical, essential part of these landscapes. 

“What we’re focusing on now is making sure that it’s not 100 years before these groves burn again,” Borden said.