Almost 20 Percent of the Planet's Sequoias Burned in Wildfires the Last Two Years

Giant sequoia trees, which were once considered nearly fireproof, are being destroyed in wildfires at rates that are alarming experts.

According to the Associated Press, wildfires last year killed an estimated 7,500 to 10,400 of the 75,000 trees native to about 70 groves in the western Sierra Nevada range. With the fires caused by lightning strikes in California this year killing an estimated 2,261 to 3,637 trees, the total of trees destroyed in the last two years alone amounts to nearly 20 percent of all giant sequoias.

The intensity of the fires that burned hot and large enough to have an impact on so many of the massive trees underscores what climate change is doing to unique parts of the environment like the sequoia forests.

Officials said the overall rising temperature of the planet in addition to a historic series of droughts in California, along with decades of fire suppression tactics have allowed such intense fires to ignite that it could cause the destruction of so many of the trees, many of which are thousands of years old.

The giant sequoia has adapted over the centuries to have a bark thick enough to protect itself from the lower intensity fires that were commonly ignited by lightning strikes in the region previously.

The lower intensity fires even help the trees, clearing other vegetation so the great sequoia can continue to grow and the fire will open the cones, causing the tree to release seeds. However, due to the dry and hot environments, the fires of the past several years have burned too hot for the seeds to grow, endangering the areas where the most trees were burned.

For more reporting from the Associated Press, see below.

Great Sequoia Trees, California Wildfires
Sequoia National Park says lightning-sparked wildfires in the past two years have killed a minimum of nearly 10,000 giant sequoia trees in California. Above, flames scorch a tree in the Windy Fire in the Trail of 100 Giants grove in Sequoia National Forest on Sept. 19, 2021. Noah Berger/Associated Press File

"The sobering reality is that we have seen another huge loss within a finite population of these iconic trees that are irreplaceable in many lifetimes," said Clay Jordan, superintendent of Sequoia and Kings Canyon National Parks. "As spectacular as these trees are, we really can't take them for granted. To ensure that they're around for our kids and grandkids and great-grandkids, some action is necessary."

California has seen its largest fires in the past five years, with last year setting a record for most acreage burned. So far, the second-largest amount of land has burned this year.

After last year's Castle and SQF Complex fires took officials by surprise by wiping out so many sequoias, extraordinary measures were taken to save the largest and oldest trees this year.

The General Sherman tree — the world's largest tree — and other ancient trees that are the backdrop for photos that often fail to capture grandeur of the giant sequoias was wrapped in a foil blanket.

A type of fire-retardant gel, similar to that used as absorbent in baby's diapers, was dropped on tree canopies that can exceed 200 feet in height. Sprinklers watered down trunks and flammable matter was raked away from trees.

The measures spared the Giant Forest, the premier grove of ancient trees in the park, but the measures couldn't be deployed everywhere.

The bulk of the Suwanee grove in the park burned in an extreme fire in the Marble Fork of the Kaweah River drainage. The Starvation Complex grove in Sequoia National Forest was largely destroyed, based on estimates of how much burned at high severity.

In 2013, the park had done climate modeling that predicted extreme fires wouldn't jeopardize sequoias for another 50 years, said Christy Brigham, chief of resource management and science at the two parks. But that was at the start of what became a punishing 5-year drought that essentially broke the model.

Amid the drought in 2015, the park saw giant sequoias torched for the first time. Two fires in 2017 killed more giant sequoias. Just over 200 giant sequoias were killed in the fires that served as a warning for what was to come.

"Then the Castle Fire happened and it was like, 'Oh, my God,'" Brigham said. "We went from the warning sign to hair on fire. To lose 7,000 trees in one fire is crazy."

A full mortality count from last year's fire is still not available because crews in the forest were in the process of confirming how many trees died when lightning struck Sept. 9, igniting the Windy Fire in Sequoia National Forest and the SQF Complex in the park, Brigham said.

Not all the news in the park's report on the fires was bleak.

There was also less damage in many of the groves where the park has routinely used prescribed fire to clear out accumulated vegetation under cooler and more humid conditions to control the blaze. The fires emphasized the need to expand that work and, where that's too risky, begin thinning forests, Jordan said.

However, areas where fire burned so hot that seeds were killed and trees can't regenerate may need additional help. For the first time, the park is considering planting seedlings to preserve the species.

"I'm not ready to give up on giant sequoias," Brigham said. "This is a call to action to better protect the remaining old growth and make our Sierra Nevada forests wildfire resilient, because the fire's coming."

Great Sequoia Trees, California Wildfires
As climate change and years of drought push wildfires to become bigger and hotter, many of the world's biggest and oldest trees, the ancient sequoias, have been killed. Above, the Windy Fire tears through the Long Meadow Grove of giant sequoia trees near The Trail of 100 Giants overnight in Sequoia National Forest on September 21, 2021, near California Hot Springs, California. David McNew/Getty Images