Yosemite’s Sequoias Survive Washburn Fire—and Might Benefit From It
Fire is still burning but has missed the Mariposa Grove, lessening risk of blazes reaching giant trees in future; ‘Now we will have an awful lot of protection’
A grove of giant sequoia trees in Yosemite National Park survived a nearby wildfire that has been burning since last week. The blaze missed the grove and formed protective cushions around the trees. Photo: Nic Coury/AFP/Getty Images
By Jim Carlton, Updated July 13, 2022 2:43 pm ET
A grove of giant sequoias in California’s Yosemite National Park not only has escaped harm from a nearby wildfire this week, but also might benefit from it, according to forestry researchers and park officials.
The Washburn Fire broke out last Thursday and initially threatened the park’s Mariposa Grove, home to about 500 sequoias, some of which are thousands of years old. But in the past few days, the blaze has slowed to a crawl and steered around the grove, hitting areas intentionally burned by park crews in recent years to form a protective cushion around the sequoias.
At 3,772 acres, the Washburn Fire is a fraction of the size of mega-blazes up to a million acres that have burned in the West in the past few years.
“In the context of what we have seen, we’ll take this every day,” said Brandon Collins, an adjunct professor of fire science at the University of California, Berkeley and a U.S. Forest Service researcher.
The Washburn Fire has also burned a section of overgrown forest near the Mariposa Grove that had already been earmarked for prescribed fire, according to Garrett Dickman, Yosemite’s forest ecologist. As a result, the sequoias will be more protected from potentially destructive wildfires in the future, he said.
“Now we will have an awful lot of protection around the grove that is going to last a while,” Mr. Dickman said.
While the fire is proving a lessening threat to the sequoias, incident commanders said Wednesday it is expected to remain active for the next several days as it chews through thick timber below the Mariposa Grove amid warm, dry conditions. They said crews would continue building containment lines where possible, and setting backfires, to help protect homes in a community up the canyon.
Smoke rose from the Washburn Fire in Yosemite National Park earlier this week.PHOTO: GODOFREDO A. VÁSQUEZ/ASSOCIATED PRESS
Yosemite has been a pioneer in the use of prescribed fires, which help to thin forests in the West that became overgrown after decades in which officials suppressed blazes to lessen the chances they would burn populated areas.
Federal officials say they were nervous about the Washburn Fire because so many giant sequoias have been burned down in recent years. Known to grow only in California’s Sierra Nevada range, the trees are among the oldest and biggest on earth and adapted to withstand the region’s frequent wildfires. The sequoias are also a popular draw for tourists.
But as in much of the Western U.S., the Sierra forests have become so crowded with trees and brush that wildfires have regularly grown too large for the sequoias to survive. Over the past two years, roughly one-fifth of giant sequoias in the U.S. has been killed or is expected to die as a result of burn damage from fires, National Park Service officials estimate.
Many of the sequoias that have died were outside the most protected parts in Sequoia and Yosemite national parks, where officials have used prescribed fire to thin out the surrounding forest, said Zeke Lunder, a wildfire consultant in Chico, Calif. “The sequoias that burned were in areas of the national forest surrounded by thickets of cedar and other trees,” Mr. Lunder said.
Mr. Dickman said some of the groves that have been burned in the past are in remote areas where it is more difficult to use prescribed fire. He said the success in protecting the Mariposa Grove shows that more such burning is needed.
“The good part of this fire is it proves prescribed fire is an effective tool,” he said.
A sequoia in Yosemite National Park’s Mariposa Grove was shrouded in Washburn Fire smoke near Wawona, Calif., earlier this week.PHOTO: TRACY BARBUTES/REUTERS
Write to Jim Carlton at jim.carlton@wsj.com