A controlled burn in Sequoia National Park. Anthony Caprio / National Park Service

The use of small, controlled burns to clear out flammable underbrush has saved thousands of giant sequoias from devastating wildfires, new research finds.

The largest trees on Earth, sequoias can reach more than 300 feet tall and live for 3,000 years, but they grow only in a narrow band of the Sierra Nevada mountains in California, where hotter, drier weather has left forests increasingly prone to wildfires. With their thick bark and high canopies, the trees can withstand small fires, but the more intense blazes seen in a warmer climate have proved deadly for thousands of trees.

Together, the 2020 Castle Fire and 2021 KNP Complex Fire killed as many as 13,000 giant sequoias, or close to a fifth of all sequoias. According to the new study, the death count would have been considerably higher without the use of prescribed burns.

The new study used aerial and satellite imagery to examine more than 26,000 giant sequoias.…