Sasha Berleman walks through 10 acres of burned woods in a coastal forest about 26 miles north of San Francisco, California. A fire ecologist for the conservation organization Audubon Canyon Ranch, she and a crew of 40 firefighters and trained volunteers had set the area ablaze three weeks earlier. Now she’s looking for signs of regeneration.

Berleman’s team was using low-intensity ground fire to remove a thick carpet of fallen pine needles and broken, sawed-off branches that littered the forest floor. The fire also took out small trees and shrubs that could have served as fuel ladders, bringing fire into the larger trees’ canopies. This formerly dense forest now looks like a wooded park, with wide spaces between the large