Forest Service using more prescribed burns in Sierra

RENO (AP) — The U.S. Forest Service has stepped up the use of prescribed burns in national forests in the Sierra Nevada to help lower the threat of catastrophic wildfires.

Residents and visitors can expect to see more smoke from fires deliberately set from an area north of Reno, around Lake Tahoe and south to the California line.

“It’s going to be in everyone’s backyard a lot more,” Rita Ayers-Vollmer, a spokeswoman for Humboldt Toiyabe National Forest, told the Reno Gazette-Journal.

Crews plan to burn roughly 300 acres along the Carson Range in 2013 — twice as much as last year and significantly more than the roughly 200 acres deliberately burned most years, said Steve Howell, a fuels specialist in the Carson Ranger District.

“It’s starting to be more and more acres. We’re trying to do more every year,” Howell said.

Prescribed burns typically target the forest’s so-called “understory” — brush, shrubs and saplings that, combined with pine needles, pine cones and other ground litter, can carry a wildfire into treetops while quickly spreading.

On the down side, prescribed fires sometimes escape control, morphing into wildfires. One set by the National Park Service near Los Alamos, N.M., in 2000 blew out of control, forcing evacuation of the entire city and destroying 235 homes.

In March of last year, a 50-acre burn started southwest of Denver by the Colorado State Forest Service exploded out of control and burned for a week, killing three and destroying more than 20 structures. The disaster prompted some critics to question whether the benefits of prescribed fires might be outweighed by their potential risk.

“Those things do happen. The risk factor is definitely there,” said Roger Walker, a professor and forestry expert at the University of Nevada, Reno.

Crews in Nevada recently conducted sizeable burns in Dog Valley outside Verdi and in Whites Creek Canyon south of Reno, and might do another one soon near Markleeville, Calif. Officials also plan a 100-acre burn along the East Fork of the Walker River.

At Lake Tahoe, 750 acres have been torched since October as part of an annual program covering about 1,200 acres, said Cheva Heck, a spokeswoman for the U.S. Forest Service Lake Tahoe Basin Management Unit.

Other methods to treat forest fuels include mechanical thinning of overgrown forests and the use of livestock to graze flammable ground vegetation.

Areas treated with prescribed fire or thinning — or sometimes both — can essentially serve as a sort of speed bump in forested terrain, slowing a wildfire’s spread and allowing firefighters a chance to gain ground.

Controlled burns can only occur when certain wind and humidity conditions exist, and planned fires often have to be canceled when they don’t.

That was the case last year, when drought conditions limited the amount of federal, state and private land treated nationwide by prescribed fire to about 1.9 million acres, according to the fire center. Typically, between 2 million and 3 million acres of land is treated.

When feasible, prescribed fires are a desirable method to treat fire fuels because the process is so affordable, Romero said. It typically costs between $30 and $200 to burn an acre of forest with fire compared to $250 to $1,000 per acre for mechanical thinning, Romero said.

Impacts from uncontrolled wildfires are far more significant to people and prescribed fires have definitely shown their worth in reducing that overall danger, he said.

“It’s a constant balancing act,” Romero said. “Fire is going to come visit at some point. We know that through experience.”