The managers of America’s national parks and forests are gradually accepting forest and range fires, once viewed as a major threat, as a vital part of the ecological cycle.
The fires that have raged through the West this year might not have been so damaging had man not spent decades quenching every blaze, the experts say. Without occasional fires, they maintain, forests and ranges become choked with over-abundant vegetation that can provide too much fuel when fire does occur.
So far this year, more than 81,000 fires have burned almost 3 million acres in the United States, Arnold Hartigan, public affairs officer for the Boise Inter-Agency Fire Center in Idaho, said. As many as 1.7 million acres of that total have been burned in the West alone since June 27, he estimated.
By comparison, 35,500 fires that burned 1.3 million acres were reported in all of 1984 in the United States, Hartigan said, adding that 1985 is probably the worst year for fires in the last 25 years.
In Canada, 8,580 fires have scorched about 1.66 million acres this year, most of them in the country’s western provinces, Hartigan said.
December in California
Although the fire season generally runs from June to mid-October, it can continue into December in warmer areas like California.
Recognizing that fires near inhabited areas are unacceptable, the experts say fires are desirable under controlled conditions in more remote areas.
“Fires actually rejuvenate forests,” John Swanson said. “They’ve shaped the forests we see today.”
Swanson is the fire management officer for the U.S. Forest Service’s Carson Ranger District, in Carson City, Nev., one of five districts responsible for the sprawling Toiyabe National Forest. With more than 4 million acres, it is the largest national forest in the lower 48 states. Ironically, Swanson is also paid to set forest fires.
Research using fire scars from petrified wood and ancient timber along with pollen and charcoal deposits on pond bottoms shows fires in forests and ranges have been around for a long time, he said. Over the centuries, vegetation as well as wildlife has adapted to fire.
The Ponderosa and Jeffrey pines that prevail in the Sierra Nevada range running north-south along California’s eastern border were nature’s choice to endure searing fires, Swanson said. The trees survived because of deep tap roots sucking water below the forest floor, a thick, corky bark to protect its living interior and quick production of cones and seeds.
“There’s a whole list of brush species and tree species that have adaptation that allow them to survive fires,” he said.
Such small animals as mice and rabbits quickly fall victim to fires but also reproduce quickly and in large numbers. Fire promotes decomposition of debris, returning nutrients to the soil for the next generation of vegetation, Swanson said. On the range, fires help maintain the balance between woody plants, such as sagebrush, and grasses.
The Indians used fire to hunt game, to clear farming lands and to defeat their foes. When the Western lands eventually became a resource for timber, mining and agriculture, fire turned into the settler’s enemy. The park and forest services continued that way of thinking in the 19th century.
“A few heretics” in forest management began questioning continual fire suppression a few decades ago, Swanson said. Their viewpoint has gradually gained support among those responsible for managing forests.
“To say ‘All fire is bad, so let’s eliminate it,’ is along the same lines as saying, ‘You’ll eliminate floods by getting rid of all water,’ ” Swanson remarked.
One of the oldest “prescribed fire” programs is in use at Yosemite National Park, which began it in 1970.
Steve Botti, chief of the park’s resources management division, said the program is “trying to simulate the natural process, reducing the fuel load. . . . We’ve seen some fairly dramatic changes in some cases, with a lot less dead debris, a lot fewer young trees, more open forests. That’s the way they were described when the forests were discovered.”
Many workers in the program, which tries to burn 2,000 to 3,000 acres yearly, are descendants of the Miwok Indians, who burned off the floor of Yosemite Valley to stimulate the growth of oaks whose acorn was the staple of the Indians’ diet.
Before a prescribed burn is set, forest managers monitor a number of conditions, starting with the amount of dead wood that has accumulated.
Swanson emphasized that prescribed burns occur only after fire lines are set up, fire engines are on call, and wind and humidity are checked.