Beware of beetles
Forest Service expecting infestation
Paul Bonnifield took his first seasonal job with the U.S. Forest Service at age 13.
It was the 1950s, and one of his tasks was to clear dead trees from trails in the Flat Tops Wilderness area.
There were a lot of dead trees. So many that the forest was spread with lines of big, dead spruce that were red until their needles fell off and then turned gray.
“The gray dullness of dead timber standing,” said Bonnifield, now a local historian. “Rarely did you see anything, rarely any elk,” he said. “Everything was just dead.”
Years before, in 1939, a spruce beetle infestation had begun in the area. The infestation lasted until 1952, when a cold snap with temperatures of 50 below zero killed the beetles.
But in the dozen years before the severe freeze, the beetles killed virtually every large spruce tree in the area, drastically changing the face of the forest.
Now, similar beetle infestations are poised to kill millions of mature spruce and Lodgepole Pine trees in Routt County and across the Western Slope of Colorado.
The infestations are natural, forest officials say. The only difference is that now people are living in and near the forests.
That means the results of large-scale tree mortality — the loss of scenic views, the fire risk from dead trees and the change in recreational options — no longer are acceptable.
Even if the trees die, the forests will grow back, just as they have done in the Flat Tops Wilderness, where new, big spruce and subalpine fir have returned the landscape to a dark green.
But officials are bracing for the possibility of hills covered in dead trees and fires that could follow.
The beetles are coming
As Andy Cadenhead, a forester with the U.S. Forest Service, drove on a dirt road into the Long Park area, he paused to point out a hillside where many trees had died. The trees — all subalpine fir — were killed because of a fungus and beetle combination.
That “fir decline” is the culprit of most of the noticeable tree deaths in Routt County, resulting in most of the bright red or orange trees seen on hillsides.
But it’s only a prelude of what’s to come.
Two beetle species, mountain pine and spruce beetles, have taken root in forests across the county.
Unlike what’s killing fir trees, pine and
spruce beetle populations have “explosive potential,” Cadenhead said.
Both beetles are very small, maybe the size of a pen point. But both have the power to wipe out entire forest stands in a few years.
On the hillside Cadenhead pointed out, the rust color of dead trees overtook the dark green color of the living. Even so, only about half the trees were dead.
“That could be comparable to a 50 percent” death rate, Cadenhead said. “Imagine everything.”
Many pine- and spruce-covered hillsides across the county could see mortality rates of 75 percent to 90 percent because of the beetles in the next few years.
“I can’t look without thinking how bad it’s going to get,” Cadenhead said.
Paving the way for beetles
Spruce and mountain pine beetles are always present in forests and typically kill a small portion of trees each year.
But to kill large numbers of trees quickly, the beetles need three conditions: old trees, dense forest stands and an environmental trigger, Cadenhead said.
Routt County has all three.
Most of Routt County’s forests are old and dense, dating back 120 to 140 years, when large fires burned across Colorado’s Western Slope.
The environmental trigger for spruce beetles is the 1997 Routt Divide Blowdown, a freak windstorm that flattened about 4 million trees in the Routt National Forest.
For mountain pine beetles, populations increase and decrease cyclically, but one trigger is drought, which came at an extreme in 2002.
The only way to stop beetle infestations is for the beetles to eat themselves out of trees, to have an extreme cold snap with temperatures of 35 to 40 degrees below zero for a few weeks, or, in the case of mountain pine beetles, to have significant relief from the drought to the tune of several years of above-average precipitation.
As unsightly as the dead trees may be, the forest naturally has, in a sense, a “boom-bust” cycle: a lot of trees grow together (the boom) and then all the trees die at once because of beetles and fires (the bust), Cadenhead said.
That renews the forest, clearing out the old trees and making room for new undergrowth and different species, Cadenhead said.
“The beetles, they’re here. They’re supposed to be here,” he said, driving through a section of forest outside Stagecoach that could be hit hard by Mountain Pine beetles. “These forests really need the beetles as part of their functioning. And they need fire, too.”
By the numbers
Beetles already have attacked thousands of acres of trees in Routt County.
The first deaths of spruce trees were seen in 2001. By 2003, there were 500,000 dead trees on about 100,000 acres, or about one-fourth of the Routt National Forest’s spruce stands. The Routt National Forest has about 1.1 million acres.
Spruce trees grow at higher elevations, so many of the trees this beetle kills won’t be seen from downtown Steamboat Springs.
Areas where the infestation is visible include Farwell Mountain and the Seedhouse Corridor, north of Steamboat near Clark.
The Mountain Pine beetle infestation is more recent, with populations taking off mostly after the 2002 drought, Cadenhead said. In this epidemic, beetles from one infested tree can kill at least 10 trees the next year, which is as fast as the beetles are known to reproduce.
That means people will start seeing large areas of dead Lodgepole Pine trees in three to five years.
“The concern is when it starts to take off, it will grow quickly,” Cadenhead said.
Dead Lodgepole Pine trees will be more noticeable than dead spruce, as they grow at lower elevations and often are in back yards, bordering roads or on nearby hills.
Hotspots for mountain pine beetles include Steamboat Lake, the Morrison Creek Drainage and the Gore Pass area.
In the Gore Pass area, 30,000 out of 70,000 acres of trees are Lodgepole Pine. All 30,000 acres are highly susceptible, Cadenhead said.
Across the West
Beetles aren’t just taking over Routt County forests — what’s happening here reflects changes taking place across the western United States.
Spruce beetles, for instance, have left thousands and thousands of acres of dead spruce trees on the Kenai Peninsula of Alaska.
Jan Hackett, with the forest management division for the Colorado State Forest Service, saw the peninsula a few years ago and was surprised by the beetle’s reach. “The hillsides were red-brown,” she said. “It was everything, thousands and thousands of acres.”
Also, before the Yellowstone fires of 1988, mountain pine beetles had killed expansive stands of pine trees.
In Colorado, the Grand Lake and Granby areas are experiencing what has been called the worst mountain pine beetle infestation across the state, said Rick Caissie, silviculturalist with the U.S. Forest Service.
There, populations of the insect took off in 1997 and have killed 440,000 trees on 83,200 acres in the county, Caissie said.
The insects have multiplied more quickly than scientific studies say they should, taking out entire tree stands in one year at times, he said.
The U.S. Forest Service did an analysis of one area and called the project “Crimson,” because entire hillsides of trees are red.
At the top of Ute Pass, you can look in one direction and see 25,000 acres of dead trees.
“Right now, they’re all bright red,” Caissie said.
The Forest Service is working with private landowners to protect valuable trees in some areas, with the goal of keeping some areas green and preventing large, intense wildfires.
The landscape may be drastically changed, but the forest won’t be destroyed: New seedlings will be waiting to sprout and start new growth again, he said.
Cadenhead reiterated the point that the death of a forest, whether by beetles or fires, is natural.
“When these stands get old, something has to trigger that stand’s renewal,” Cadenhead said. “In many cases, it’s the beetles and then fires.”
But for Bonnifield, that still means a loss of old, big trees.
“We can come up with reasons, ‘Oh, that’s natural,'” he said about explaining the beetles. “Still, that great, big, beautiful timber is gone.”
— To reach Susan Bacon, call 871-4203
or e-mail firstname.lastname@example.org
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