California's enormous Rim Fire had a devastating effect on soils and vegetation, according to Forest Service ecologists. A full 60 square miles (155 square kilometers) burned so severely that all vegetation died, a senior wildland ecologist told the Associated Press. "In other words, it's nuked," ecologist Jay Miller said.
The Rim Fire has scorched some 400 square miles (1,000 square km) of forest since Aug. 17, when it was sparked by a hunter's illegal fire. Most of the intense burn was in the Stanislaus National Forest, Miller told the AP. Approximately 7 percent of fire zone also suffered a high severity soil burn, and 37 percent received a burn of moderate severity, according to a survey by a Forest Service Burned Area Emergency Response team. Intense flames can create a layer of plant oils that keep soil from absorbing water, as well as destroying plant roots and organic matter that prevents erosion.
Despite the damage, the forests are already showing signs of new plant growth. In Yosemite National Park, campgrounds and giant sequoia groves that closed while flames raged nearby have reopened, along with many main roads. The Rim Fire continues to smolder in parts of Yosemite's forest. National Park system policy is to let non-threatening fires burn.