Fighting Fire With Fire! Controlled Burns Saved Nearly 2,000 Giant Sequoias
Quick Summary
A new study found that carefully planned, controlled fires helped save about 1,900 giant sequoia trees from deadly wildfires in California. Trees that had received these treatments were four times more likely to survive. The findings give scientists and forest managers a powerful new reason to use this ancient technique.
What Happened?
Giant sequoias are the largest trees on Earth. Some of them are over 2,000 years old and as tall as a 26-story building. They live in groves in California’s Sierra Nevada mountains, and they have survived hundreds of natural wildfires over their long lives.
But something changed. In 2020 and 2021, two enormous wildfires called the Castle Fire and the KNP Complex Fire tore through 19 sequoia groves. These were not ordinary fires. They were supercharged by years of dry weather and built-up dead wood on the forest floor. They burned so hot that even ancient, fire-resistant sequoias could not survive. The fires killed about one in every five mature giant sequoias.
Scientists from UC Davis wanted to find out if anything could have stopped this. They looked at roughly 26,400 sequoia trees in those 19 groves. Then they compared trees that had received something called a prescribed burn with trees that had not.
A prescribed burn is a carefully planned, controlled fire. Forest rangers deliberately burn small sections of forest on purpose. This clears away dead branches and dry leaves on the ground. It is like cleaning up a pile of dry newspaper before a campfire can get too close. With less fuel on the ground, a real wildfire burns much less intensely.
The results were striking. Sequoias in areas that had been treated with prescribed burns were nearly four times more likely to survive the megafires. The researchers estimated that those earlier, planned burns saved the lives of about 1,900 ancient trees.
Why Does It Matter?
Giant sequoias are irreplaceable. A tree that is 1,000 years old cannot be regrown in a human lifetime. Scientists say that more than 17 percent of all mature giant sequoias have now been lost to wildfire since 2015. That is a dramatic change: in the 30 years before that, less than 1 percent were killed by fire.
This study, published in the scientific journal Nature Communications, gives forest managers a clear answer. Using prescribed burns — a technique that Native American communities have used for thousands of years — really works, even against today’s extreme fires.
The news is hopeful. Scientists estimate that if every sequoia grove in the affected area had been treated with prescribed burns beforehand, an additional 3,900 trees might have survived. That means there is still a lot that people can do to protect these magnificent trees going forward.
Big Words
- Prescribed burn — a carefully planned, controlled fire set by forest rangers to clear away dead plants and leaves so future wildfires won’t burn as hot or spread as fast
- Sequoia — one of the world’s largest and oldest types of tree, found only in California; the biggest ones can be wider than a city bus is long
- Megafire — an unusually large, intense wildfire that burns far more land and far more intensely than a normal wildfire
- Sierra Nevada — a large mountain range running through eastern California, home to many of the world’s giant sequoia groves
- Conservation — the work of protecting and preserving natural things, like animals, plants, or forests, from harm
Fun Fact
The giant sequoia tree called General Sherman in Sequoia National Park is the largest living tree on Earth by volume. It weighs about as much as 15 adult blue whales and has been alive for over 2,700 years.
Think About It
People sometimes worry about setting fires on purpose near forests. But this study shows those small, planned fires can actually protect the trees. Can you think of other examples where a little bit of something difficult or dangerous might actually prevent a bigger problem?
Sources
- UC Davis — ‘Prescribed Burns Saved Thousands of Giant Sequoias’ (July 2026)
- ScienceDaily — ‘The best way to save giant sequoias may be more fire’ (July 26, 2026)
- Phys.org — ‘Record fires killed nearly 1 in 5 mature giant sequoias, but controlled burns can boost survival’ (July 21, 2026)
- Nature Communications — Dixon et al., ‘Previous prescribed burns saved thousands of ancient sequoias during historically unprecedented wildfires’ (2026)