Mancos – A plan to clear-cut hundreds of acres of dying aspen around Mancos is not a response to the die-off of the tree across the West, but it could yield important clues for puzzled scientists, San Juan National Forest officials said.
Foresters will find out in the next couple of years whether their effort gets to the roots of the aspen’s problems.
“We think the clear-cut of these reduced stands will give us a better chance of saving them,” said Dolores public lands manager Steven Beverlin.
It sounds counterintuitive, but aspen thrive after severe disturbances, such as forest fires, landslides and logging. This is because they reproduce asexually from their giant shared roots, which send out shoots called suckers. Clear-cutting encourages suckering because aspen leaves produce a chemical inhibitor that keeps sprouts in check.
“The aspen is masochistic,” said Forest Service ecologist Wayne Shepperd, with the Rocky Mountain Research Station in Fort Collins. After fire or clear-cutting, experts variously estimate the potential number of aspen suckers at anywhere between 15,000 to 60,000 per acre.
Parts of southwestern Colorado, historically home to the biggest stands of the biggest aspen in the country, have been particularly hard hit by the recent and mysteriously rapid decline of a tree that had become the most widely dispersed species in North America.
With gold and scarlet aspen leaves aflame on ridges around southwestern Colorado, the bare spots are even more painfully obvious.
Up to 60 percent of the aspen stands in the Turkey Knolls area 12 miles north of Mancos are dead or dying, compared with about 10 percent mortality in 2002, forester Phil Kemp said.
The Turkey Knolls timber sale, which would harvest aspen on 290 to 375 acres in spring or summer of 2007, has been in the works for more than a year. The Forest Service has held a timber sale in the area each decade. Local mills use the wood to make everything from wall paneling to excelsior (curved wood shavings used in packing and for storing water in swamp coolers).
“It’s coincidental that the sale is happening at the same time as this accelerated die-off we’re seeing,” Beverlin said. “But we are going to lose these stands anyway. This gives us a chance of rejuvenating them instead of just watching them die.”
The concern with the aspen’s current fade-out is that root systems also might be dying. If the sick roots seen in some isolated places are a widespread phenomenon, the aspen won’t be making a comeback, Shepperd said.
That is why Shepperd and fellow Forest Service aspen ecologist Dale Bartos, based in Logan, Utah, have expressed concerns that clear-cutting a stand with unhealthy roots could simply hasten its demise.
No comprehensive, orchestrated investigations into the aspen decline have taken place yet, although aspen experts met in Utah earlier this month to share notes on die-off across the Rockies and parts of Canada.
Theories on why aspen are declining include some deadly, cascading combination of old age, drought, fire suppression, overgrazing of young trees by wildlife and livestock, insects, fungus or the loss of genetic vigor.
Bartos has estimated that 10 percent, or hundreds of thousands of acres, of aspen across the West could die in the next several years.
Shepperd said he fears that percentage could be greatly underestimated.
“We just don’t know,” he said.
Staff writer Electa Draper can be reached at 970-385-0917 or edraper@denverpost.com.
