Firefighters battling a 2,050-acre wilderness fire here were able to divert the blaze away from the famous Giant Forest grove of ancient sequoias largely because of a controversial program of controlled burning that has been followed at the park for nearly a decade, National Park Service officials said Tuesday.
Under the policy, implemented in 1979, rangers have been setting controlled fires in some parts of Sequoia National Park and letting lightning-set wildfires burn in forested wilderness areas.
Free of Natural Debris
The fires were intended to reduce the build-up of fallen trees, pine needles, leaves, and other natural debris that had accumulated on the forest floor over the previous decades, when all fires in the park were immediately extinguished.
The tactic made it safe to set backfires Sunday when the wildfire threatened the grove of sequoias, some of which are 3,000 years old.
“Those backfires were low-key and under control . . . just like we’d planned,” said Larry Bancroft, acting park superintendent. The backfires could be used because several controlled burns set in 1984 had reduced the combustible fuels to safe levels, he explained. “This worked just like it was supposed to.”
By Tuesday, the Buckeye Fire--named after the Buckeye Flat Campground near its starting point--was only 15% contained, and nearly 1,000 firefighters, 31 fire engines, half a dozen helicopters and an equal number of fire-retardant bombers were fighting the stubborn blaze, which left a pall of smoke hanging over most of the area, hindering visibility and flight operations.
No one was predicting when the fire would be controlled, but park spokesman Bill Tweed said that the danger to any sequoias or park structures appeared to be past. Some Southern California Edison Co. power poles were lost and a telephone relay station was threatened for a while, officials said.
Because much of the fire is in nearly inaccessible wilderness, it took some fire crews half a day just to reach the fire lines, and then they could work only by hanging onto limbs or rocks with one hand while they cut and scratched out a fire line.
In the smoky quiet of the giant sequoia grove that had been back-burned, the forest floor was still smoldering Tuesday, but the danger to Giant Forest appeared to have been headed off.
Policies Under Review
The fire comes at a time when the National Park Service is re-evaluating its fire management policies as a result of fires that burned about a million acres of Yellowstone National Park this summer. One of those big fires was set by lightning and allowed to burn.
The so-called “let-burn” policy--also used in Sequoia, Kings Canyon and Yosemite national parks in California--was denounced by some Yellowstone-area residents and the Reagan Administration has suspended the policy pending further studies.
Comparisons between Rocky Mountain parks and those in the Sierra Nevada are difficult to make, officials said.
“Geographically, Yellowstone and Sequoia parks are very different worlds,” Tweed said. Yellowstone, high on a plateau, has dense stands of lodgepole pines that are highly combustible. Major fires are a historic part of such forests, Tweed explained.
The Sierra Nevada is different in that its forests are made up of larger, more widely spaced evergreen trees that are more resistant to fire. Sequoia gigantea-- cousin of the coastal redwoods--is the largest and oldest of these trees, and the most fire-resistant of all, Tweed said.
Historically, fire was a natural part of these forests, helping keep them healthy and vigorous. Sequoias cannot reproduce without fires to clean out the forest floor and help the seeds germinate, Tweed noted.
When settlers started fighting fires in the Sierra a century or more ago, they disrupted the natural order of things by allowing combustible fuels to accumulate to dangerous levels. By 1965, park scientists began experimenting with ways to reintroduce fire into the environment, and from these early experiments came the current fire policies, implemented in 1979.
Unlike Yellowstone rangers, those in Sequoia have used controlled burns to reduce “fuel loads” in places like Giant Forest, torching 40 to 110 acres at a time when weather conditions were favorable, Tweed said.
Similarly, under appropriate conditions, park officials let burn some fires that were set by lightning. Up to 2,000 acres in a single fire had been allowed to burn until the current moratorium was imposed by Washington.
The Buckeye fire, believed to have been accidentally started by a fisherman, flared early Sunday in the steep, brushy gorge carved by the middle fork of the Kaweah River, just east of park headquarters at Ash Mountain.