Experts talk about the remarkable resilience of Yosemite's Giant Sequoia trees

FRESNO, Calif. (KFSN) -- As the Washburn Fire continues to spread, having burned more than 3,500 acres as of Tuesday night, all eyes are on the Giant Sequoias of Yosemite.

Firefighters are working to save the mighty trees, which until recently, were believed to be invincible.

The Giant Sequoias have evolved over hundreds of years to be mostly fire-resistant, but over the last few years drought conditions have weakened them.

Action News spoke with Alejandra Borunda, an environment writer for National Geographic.

"In the past six years, there's been an incredible shift in the climate system and in wildfire behavior that has ended up killing about 20% of the mature trees across the state," said Borunda.

That's an alarming statistic, but none of the Giant Sequoias have been destroyed by the Washburn fire yet.

She says there are a number of factors that have helped protect the giants.

For 50 years, Yosemite has had prescribed burns in and around the Mariposa Grove - that has helped crews in the area.

Also, a temporary sprinkler system has been soaking the trunks of the trees.

"They're just remarkable things that have lived through so much, have lived through an incredible amount of history," she says.

The base of some of the Sequoias have been burned a bit, but Borunda said that could actually be beneficial.

"Sequoias actually need fire to regenerate. Their seeds don't open without fire. There's a chance this burning could have helped with regeneration," she said.

Borunda says it will be a few years before we know just how much the Giant Sequoias benefited from the burn.