Study: Wildfires Save Majestic Trees
Aug. 5, 2002 -- Minnesota's state tree, the red pine, stands in spectacular clusters reaching up to 80 feet into the sky.
But new research says the future of these majestic pines is at risk due to decades of improperly trying to protect them. As in many national forests across the country, people have been suppressing the natural occurrence of wildfire in northeastern Minnesota's Superior National Forest.
It's now known the red pine, which can live for up to 250 years, relies on fires to clear the forest floor and allow plenty of light and soil nutrients to nourish its seedlings. A study released today predicts the red pines in Minnesota's national forest — among the last remaining natural groves in the country — will disappear unless fire is reintroduced into the region.
Big Fires Spark Fiery Debate
Managing wildfires has become a contentious issue that has pitted environmental groups against those who feel regulations have suppressed efforts to thin forests. Clashes have become especially sharp during this year's unusually intense wildfire season. So far an estimated 53,070 fires have scorched 4.3 million acres of forest land this year, more than double the 10-year average, according to U.S. Forest Service statistics.
The wildfires have been more intense and tougher to suppress due to the fact that forest fuels — underbrush and fallen trees — have built up over a century of fire suppression.
Last month, Californians feared giant sequoia trees would be lost as the so-called McNalley fire leaped dangerously close to the Sequoia National Forest. Firefighters successfully fended off the flames from the ancient forest.
Matt Mathes of the Forest Service says it's unlikely that sequoias, which can live more than 3,200 years, could survive massive wildfires. Like red pines, sequoias are designed to thrive when periodic, small ground wildfires sweep through a forest. But the buildup of fuels in U.S. forests now produce large wildfires that could jump higher on the giant trees where they are more susceptible to damage.
"The trees have not had enough time to evolve and adapt to the increase in forest fuels. We don't know for sure [if the trees could survive], but it's something we don't really want to find out," says Mathes.
Computer models offer a more hopeful prospect for Minnesota's red pines. The research released today has determined there is little risk the red pine could be engulfed and destroyed by a large wildfire.
"Part of the concern is because there has been a lot of fuel built up around the pines, there would be a risk of the red pines being completely removed," says Robert Scheller, a forest ecologist at the University of Wisconsin in Madison who is presenting the results of the new U.S. Forest Service study at the annual meeting of the Ecological Society of America. "Now it appears that's not a concern — at least that's what our models predict."
Still, the unruly, massive wildfires this season have led lawmakers to vow to do something about fuel buildup in forests.
Seeking a Fast Solution
Last week a group of senators promised to enact legislation that would ease environmental rules so forest fuels could be thinned out quickly in an estimated 10 million acres of forest land in the Western United States.
"The crisis we are experiencing this year, fueled by a terrible drought and massive wildfires, has compelled us to take action now to launch an effort to save our forests," said Sen. Pete Domenici, R-N.M., at a Capitol Hill news conference.
But environmentalists contend the move would only serve the timber industry by permitting the harvest of large, valuable tree stands that host diverse wildlife in the nation's forest.
"It's not necessary to suspend environmental laws to do protect these forests," says Bob Dale, field director at the Forest Service Employees for Environmental Ethics. "By suspending environmental laws, we may end up doing things without a lot of care and caution."
Foresters say there is a middle ground. By clearing out brush and small trees and setting controlled burns where possible, forest fuels — and the risk of massive wildfires — can be reduced, while large trees and properties are preserved. But they also stress there is no single solution.
For Minnesota's red pines, Scheller argues prescribed fire will be necessary.
"What we're talking about is conserving the wilderness character of the region," he says. "The red pine is part of our national heritage. If you look at cost-effectiveness, I think there is little choice but to use controlled burns."
Peering Into the Future
Scheller used the landscape simulation model called LANDIS to predict how tree groves in Minnesota's Superior National Forest would respond to wildfire. The program calculates the effects of fire, taking into account tree species' ages and life histories as well as forest composition, climate and soil.
In his study, Scheller looked at four different scenarios over a 300-year time period. In one scenario, fires continue to be completely suppressed, in the others, fires occur once every 50 years, every 100 years and every 300 years.
The models show that red pines would do very well if fires swept through the region every 100 years and actually would increase if fires occurred every 50 years. When fires were suppressed or reduced to once every 300 years, the trees would die out. Other trees, including the aspen, birch trees and jack pine, which depends on fires to help release its seeds from its cones, also suffered when fires were suppressed entirely or to once every 300 years.
"An analogy might be your garden where you prepare the seedbed for different plants by clearing it and providing a lot of light," Scheller says. "That's what fire does for the red pine and other large trees."
But while controlled burns may be essential to the red pine's survival, Scheller says it's hard to say if the same techniques could help save other trees in different areas. Each region, say foresters, needs its own prescription for survival.
"Managing the ecosystem is very complex and does not have one answer," says Art Gaffrey, the forest supervisor for California's Sequoia National Forest. "Each tree grove is unique — just like people's health. There are a number of conditions so we need a mixture of answers to solve the problem."