Billions of beetles have been chewing their way through spruce trees all summer.
They tunnel under the bark, finding warm places to lay their eggs and continue the epidemic that forest officials say could kill almost every tree in the 400,000 acres of spruce in the Routt National Forest within the next few years.
But as the beetles have eaten, a team of workers have been chipping away -- with axes, bark peelers and chemical sprays -- at the epidemic.
Work began immediately after the 1997 Routt Divide Blowdown, in which an intense windstorm felled trees in a 13,000-acre area, creating perfect conditions for beetle populations to explode.
Now, the U.S. Forest Service does not aim to stop the epidemic. Beetle epidemics are not only natural to the forests, but officials say trying to halt the population explosions would be impossible.
Rather, the goal is to keep alive valuable stands of trees, such as those in the Steamboat Ski Area or at popular campgrounds.
The team is holding its own in those areas, said Andy Cadenhead, a forester with the U.S. Forest Service.
Although he expects the infestation will rival any seen since the state was settled, he also expects that 5 percent to 20 percent of mature spruce stands in the area could survive.
Each mature tree that survives will be a result of focused efforts on the part of the Steamboat Ski and Resort Corp., the Forest Service and others.
"If we hadn't done what we've already done for four years here, it'd be hard to find a live spruce on the mountain," Cadenhead said.
What they're doing
Last Thursday, about 20 Forest Service employees piled into trucks and headed up Mount Werner, the same as they have done for most of the summer and fall.
On last week's trip, they brought chain saws, axes, geographic positioning system equipment and lunches, and split up into crews of three or four.
Each crew hiked to the first infected tree on its list, chopped it down and scraped off its bark to kill the beetles that had burrowed into it.
They've scoured the mountain all summer, finding and recording the positions of spruce and pine trees that have been infected by beetles.
The Forest Service is concentrating its efforts on saving trees on the ski mountain because it has an interest in protecting the world-class ski resort that it agreed could be built on forest land, Cadenhead said.
About 300 trees on the mountain have been chopped and peeled this year. There are another 300 that are marked to be treated before winter. The trees are, in essence, already dead, and not culling them has serious implications. For each infected tree that isn't treated, the beetles that emerge in the spring could kill 15 to 20 more trees next year.
The Forest Service has used a combination of other pest-management strategies, such as setting up traps and spraying live trees with pesticides, to combat the beetles in valuable stands.
The group's first large-scale trap, called a "lethal trap," was made two weeks ago, in an area about a mile from the ski area where about 1,000 infested trees were found. In the trap, 240 uninfected trees were cut down and doused with chemicals and pesticides.
When new beetles fly during the next two springs, they should smell the attractive chemicals in the trap and burrow into the downed trees, consuming the poison on the trees and dying.
If the trap doesn't work, the beetles emerging next spring could pick out trees on the mountain.
"If the wind was blowing in the right way and the bugs came in, it could really put at risk everything that we've done," Cadenhead said.
Although the ski mountain has a variety of trees, including aspen, fir and pines, the loss of spruce trees would impact skiing, Cadenhead said.
The idea is to protect Steamboat from suffering the same fate as Brian Head Resort, near Cedar City, Utah, which was once home to a spruce forest and now is largely bald because of a spruce beetle epidemic that began in the 1990s.
One of the more controversial aspects of the Forest Service's plan to combat the beetles involves thinning healthy stands through logging.
About 5,000 acres of forest north of Steamboat off Seedhouse Road have been identified for logging. The Forest Service marked about one in every three or four trees in the area, for a total of about 50,000 trees that could be removed by commercial logging operations next summer.
With logging, the trees that remain won't have as much competition for light and water and won't create as strong of a beetle-attracting odor, so they could have an easier time surviving the infestation, Cadenhead said.
The amount of forest to be logged is small compared to the hundreds of thousands of acres that could be infested by beetles, he said. To minimize the negative impacts of logging, practices such as keeping new roads at a minimum and removing tree branches before the trees are brought out will be encouraged, Cadenhead said.
Nonetheless, the decision to log didn't sit well with Colorado Wild, an environmental group that appealed the plan. The appeal was overridden by the regional forester.
One risk of thinning is that it could make the forest more susceptible to future blown-down events, re-creating another good environment for the beetles to thrive, said Rocky Smith, the Forest Watch campaign director for the group.
Despite efforts to keep impacts low, Smith said the logging could create unwanted roads and traffic. Perhaps most importantly, he said it took away from some of the area's beautiful old-growth stands.
"Going into the backcountry and thinning an old-growth forest -- that's just not good, and it's probably not going to work," Smith said.
To Cadenhead, the beetles already have signed a death warrant for most of the forest, but logging provides a way to try to save some trees while also bringing in money that can be used to save other stands.
"What we're trying to leave is mature stands of spruce and lodgepole (pine)," he said. "If we don't do this logging, we know we won't have these stands."
Mountain Pine beetles
At the same time that spruce beetles are chomping through spruce trees at higher elevations, pine trees are facing their own foe: the mountain pine beetle.
Similar to spruce beetles, the mountain pine beetles deposit larvae under the bark of pine trees, which then feed on the tree's water and food transport system. The beetles also deposit a fungus that harms the tree.
In the past few years, populations of the mountain pine beetle have grown quickly, partly because of persistent hot, dry conditions.
Pine beetles are hitting the ski area as well, and since the Forest Service and Ski Corp. are working together to combat the beetles, the ski area has taken the lead in treating infested pine trees.
In addition to cutting and peeling bark from infested trees, the ski area has identified and sprayed trees that are crucial to the operation of the resort, such as those hiding the radio towers, providing wind protection or making some of the resort's best known tree-skiing runs.
"We've put a lot of resources into it," said Lyn Halliday, Ski Corp. director of environmental affairs. "We have enough (tree) diversity, so I don't think you'd really see any drastic (changes)."
In addition to infesting trees on the ski mountain, the pine beetles have made their way into forests across the county, with hot spots around Hahn's Peak and Steamboat Lake, where state park managers are working on methods to control the beetles.
Officials with the Colorado State Forest Service also are working to keep the beetles off state and private land. They provide forest management advice to private landowners who see trees that might be infected and want to prevent the epidemic from killing off important trees.
A regional perspective
The most recent recorded epidemic of spruce beetles took place in Colorado in the mid-1900s near the Flattops Wilderness Area.
During that epidemic, about 250,000 acres of spruce forest were affected, said Frank Cross, a forest health leader for the U.S. Forest Service Rocky Mountain Region. The epidemic only ended because most of the beetles were killed in an extremely cold winter in 1950.
That was the biggest recorded epidemic until beetles infested and killed millions of acres of spruce trees on the Kenai Peninsula of Alaska during the past few decades.
Now, with the potential for beetles to infest forests across the several million acres of spruce in Colorado, the state could see an infestation of a similar scale.
For the forest, such epidemics are part of a natural recycling process. Once trees age to 100 years or more, they are more susceptible to attack. With different beetles attacking different trees, the face of the forests in Colorado and other western states could change drastically in the next few years and decades.
Cross said he expects people will really start noticing the dead trees in the next two years.
"It's almost like the perfect storm," Cross said. "There are all these conditions that are coming together right at the same time that make it really good for beetles to attack and kill trees."
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