Ancient sequoias safe for now as crews continue battling 3,500-acre Washburn fire in Yosemite

But sequoias have also evolved with wildfire and in fact rely on extreme heat to help release their seeds. Crystal Kolden, a fire scientist at UC Merced who has been tracking the blaze, said she was “not worried” about the trees in Mariposa Grove. “They’ve been doing prescribed burns in that grove for over 50 years, and it’s early in the season yet,” Kolden said via email. “This fire should actually be pretty beneficial for them, and it is much better for them to burn in July — which is normally when most of the lightning ignitions are in Yosemite, so it’s the natural fire timing — rather than in September.”