As flames advanced toward Big Bear Valley from four directions Oct. 28, U.S. Forest Service Fire Battalion Chief Betty Ashe took the one bulldozer driver she had and put him to work.
Other crews arrived the next day, and within 48 hours the bulldozers had scraped and chewed through 12 miles of forest, clearing or widening firebreaks around the mountain community.
"We pushed a lot of dirt," Ashe said.In the bulldozers' path lay rare rubber boa snakes, scores of tiny endangered plants and the historic remains of Southern California's largest gold mining site and ancient Native American villages.
The flames never hit Big Bear, thanks to cool rains, fog and thousands of firefighters, but the fire lines will remain for years, possibly decades.
Many firefighters and federal forestry officials say that's a good thing; the next time Big Bear is threatened by a wildfire, it will be better protected. But some scientists say the lines will be scars on the land that could cause floods and already may have harmed fragile wildlife.
"Once we have a scar on the mountains, that scar's going to be around for the rest of my life. My kids may see that scar," said Tom Scott, a zoologist and conservation biologist with UC Riverside and UC Berkeley. "Nobody tries to intentionally damage anything, and no one wants to see firefighters' lives threatened ... but absent long-term management, you could see real impacts on species."
He and other scientists say no one truly knows the impact of firefighting on wild lands, particularly bulldozers scraping to bare earth and aerial drops of chemical fire retardant. Two groups have sued the U.S. Forest Service to force national studies on those issues.
In Southern California, where blazes continue to threaten rapidly disappearing wilderness that is home to hundreds of threatened or endangered species, an on-the-ground balancing act has emerged.
Last week, the priority of fire crews battling the out-of-control blaze was to protect human life and property.
This week, teams of biologists, botanists and archeologists are combing the forest and chaparral to see what damage may have been done by the firefighting efforts.
"The No. 1 thing is we just have so many species that are unique to this area.... We have dozens of sensitive and 12 federally listed plant species in Big Bear, and over 100 sensitive species in the Mountain Top district," said Linda Stamer, a biologist for the San Bernardino National Forest.
Stamer said that initial assessments showed many sensitive areas appeared to have been untouched: "We're pretty pleased. As much as we can be."
Even as they bulldozed and dropped red retardant, fire crews applied lessons from previous fires.
"If there's an opportunity for us not to bulldoze a ridge that has threatened and endangered species, we won't," said Donald Feser, fire chief in the Angeles National Forest who served as deputy incident commander in the Big Bear area. "But we're not going to sabotage getting our job done."
Before Feser dispatched bulldozers to perimeter lines around Big Bear last week, he was informed by a resource advisor of the tiny San Bernardino Mountain bladder pod, a wispy little plant that is federally endangered.
He also had mapped areas of rare pebble plains soils that are home to several threatened plants. Historic and cultural sites were also included in briefings.
"We as firemen understand the value of our wildlife and our cultural resources. There has to be a compromise between fire suppression and wildlife protection," said Ashe, who said she ordered bulldozer operators to do "high passes" over sensitive grasses and known areas of rare species when possible. "You go around it to protect it if you can ... but our first priority is human life.... I'm not going to let a house burn to save a tree."
Federal biologists who have been fighting to preserve the species agreed. U.S. Fish and Wildlife personnel were informed that rare, protected species could be harmed, but in an emergency permits are not required to destroy habitat or species.
"At a certain point the decision was [wildlife] resource issues are moot right now," Stamer said.
After the fires cool and before torrential rains set in, hand crews try to pull manzanita plants or pine needle duff or other cover for animals back over the lines. Once damage has been assessed, rehabilitation can begin.
Some conservationists said policies banning home construction in sensitive areas or mandating fireproof construction are more important than bulldozer lines.
Two lawsuits have been brought in an attempt to examine the impacts of active firefighting on wild lands. On Oct. 14, the Forest Service Employees for Environmental Ethics filed suit in U.S. District Court in Montana to force studies of the effects of flame retardant and to examine alternatives.
In April the Sierra Club won a suit against the U.S. Forest Service halting a timber sale because the effects of hundreds of miles of fire line and tons of flame retardant in the Big Bar fires in Northern California hadn't been adequately examined.
Andy Stahl, executive director of the Forest Service employees group, said fertilizers in flame retardant kill fish, and no complete studies of health effects on humans have been completed.
Stahl contends that flame retardant and bulldozer lines are often useless. He said in heavy winds, flame walls could skip over a 100-foot-wide fire line "like a pebble skipping over a pond."
U.S. Forest Service regional spokesman Dave Reider said that although high winds could render bulldozer lines ineffectual, in other situations they could provide a haven for firefighters, and were a proven method for slowing and stopping fires.