“If you look at the Sierra Nevada as a whole, by far the largest portion hasn’t seen a fire since the 1910s and 1920s, which is very unnatural,” said Safford, who has authored several papers on the increasing wildlife severity across California’s mountain ranges. “This one isn’t stopping for a while.”
Since a 1988 fire impacted nearly one third of Yellowstone National Park, forestry officials have begun rethinking suppression policies. Yosemite has adopted an aggressive plan of prescribed burns, while allowing backcountry fires caused by lightning strikes to burn unimpeded as long as they don’t threaten park facilities.
“Yosemite is one of the biggest experimental landscapes for prescribed fire and it’s going to pay off,” Safford said. “The Rim Fire is starting to hit all those old fire scars.”
The 350-mile-long Sierra Nevada is a unique mountain system in the U.S. with its Mediterranean climate, which means four-to-six months of drought every summer. California’s mountain flora is designed to burn and even flourish and regenerate healthier after a fast-moving fire.
Instead the Rim Fire is killing everything in its path. The understory ignites trees, and wind is sweeping the fire from treetop-to-treetop in 300-foot walls of flame.
Scientists also expect the impact on wildlife to be severe. The fire has encompassed nearly the entire migratory range of deer in the region, and the burning treetops likely displaced many of the remaining 300 members of a subset of Great Gray Owl along the Yosemite border, said Daniel Applebee of the California Department of Fish and Wildlife.
“Because their population is so small, any loss is significant,” Applebee said.
The fire also cut through habitat of the Pacific fisher, a weasel-like animal that is listed for state and federal protections. The fire has fragmented its range, likely leaving it nowhere to expand, Applebee said.