Wednesday, June 2, 2004

Fire benefits aspen stands

U.S. Forest Service tries to reverse decline of aspen tree populations

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By GREG STAHL
Express Staff Writer

To help spur growth of ailing aspen tree stands, managers at the Sawtooth National Recreation Area are going to try to burn them.

Aspen stands in the Intermountain West, including Central Idaho, are on the decline. SNRA Wildlife Biologist Bobbi Filbert and Fuels Planner Matt Filbert are working on a project that could help reverse the trend. Express photo by Greg Stahl

Years of fire suppression, grazing and drought have contributed to a slow decline of aspen trees across the Intermountain West. Recent studies indicate that thousands of acres of aspen forests have been lost in Idaho due to fire suppression.

Aspens rely on disturbance, like fire, to regenerate, and in the SNRA aspen populations are visibly on the decline. Aspens are gradually being overrun by coniferous species. As they vanish, an important form of habitat is vanishing, too.

"I think the key for any healthy system is disturbance," said SNRA Fuels Planner Matt Filbert. "Until we get some disturbance back in there, these aspen stands are going to continue to deteriorate. It’s a scientific fact."

This fall at the soonest, SNRA managers hope to reintroduce fire to a 400-acre aspen stand in the Pole Creek valley, which divides the Boulder Mountains from the White Cloud Mountains. The deteriorating aspen stands are about 2 miles southeast of Smiley Creek Lodge.

According to the U.S. Forest Service, fire is beneficial to aspen stands in two ways: It kills mature trees, which stimulates its root systems to produce new stems, and it kills young conifer saplings that will otherwise eventually out-compete and crowd out the aspens.

If the experiment works in the Pole Creek area, the forest managers may look to other deteriorating aspen stands in the 756,000-acre SNRA.

"Long term, I think we’d definitely like to look at other aspen areas on the SNRA," Wildlife Biologist Bobbi Filbert said. "The results of this project will give us an idea of what to expect in our other stands."

"Long term, I think we’d definitely like to look at other aspen areas on the SNRA," Wildlife Biologist Bobbi Filbert said. "The results of this project will give us an idea of what to expect in our other stands." Express photo by Greg Stahl

This isn’t the first time SNRA officials have tried to revive the ailing Pole Creek aspen stand. In the late-1990s, biologists used a tractor to rip at the roots of trees on the outside periphery of the stand. The concept was similar to the premise proposed this summer, only the disturbance was introduced through manual means.

That effort, however, didn’t work as well as hoped. Using fire might produce different results.

"It’s a real opportunity," said SNRA Area Ranger Sarah Baldwin. "We’re looking at it as a learning exercise. Whether we do more of this will hinge on this project, so I think it’s kind of exciting."

According to biologists, the reasons for the decline of aspen trees vary.

"It’s not just one thing. It’s several things working together," Bobbi Filbert said. Fire suppression, overgrazing and drought are among the reasons aspen trees are increasingly being overrun by surrounding coniferous forests.

Filbert said retaining aspens on the landscape offers many benefits. First, because they are wet trees, they produce effective fuel breaks and could slow down a catastrophic wildfire.

Aspen stands are also rich wildlife habitat areas. Restoring aspen communities would benefit elk and mule deer that use the areas for spring, summer and fall range and would enhance the diversity of habitat available for cavity nesting birds and small mammals as well.

Aspen stands also use less water than conifers, increasing water yields for stream flows and increased production of undergrowth vegetation.

"Our window of opportunity to reverse this decline of aspen is limited," according to a letter penned by Baldwin. "Many opportunities to maintain aspen are lost yearly, as old and suppressed stands become more susceptible to disease and suffer die-back in their root systems."

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To get involved:

Comments on the SNRA’s aspen regeneration project should be directed to Bobbi Filbert, SNRA, HC64 Box 8291, Ketchum, ID 83340.

To be most useful, comments should be received by June 25. For more information, call Bobbi Filbert at (208) 727-5000.

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