From: Boulder Daily Camera
Scroll down for several stories from 2007-2008
Beetle-mania: Tree-killing insects poised to infest Boulder County
This ponderosa pine tree in Rocky Mountain National Park was killed last year by mountain pine beetles. Officials warn that the infestation is spreading into Boulder County. Photo by Sammy Dallal
They're coming.
Like unwanted houseguests, like credit card bills at the end of the month, like mean hangovers after long nights of drinking — they're coming.
The mountain pine beetle, responsible for decimating more than 5 million lodgepole pine trees on the Western Slope, already has planted a toehold in Boulder County.
Now, as a new summer season approaches, forest managers and biologists are carefully watching to see whether the beetles' presence develops into a stranglehold on the area's forests.
"We're paying a lot of attention to it because this could be the beginning of the epidemic in Boulder County," said Chad Julian, senior resource specialist with Boulder County Parks and Open Space.
And a full-blown mountain pine beetle infestation — one in which the rice-grain-sized insects make the transition from higher-elevation lodgepole pines to lower-elevation ponderosa pines — could eventually turn treasured forests throughout western Boulder County into brown swaths of dead, snap-dry timber primed to burn.
According to an aerial survey conducted last year by the U.S. Forest Service, about 6,000 trees on a little less than 2,000 acres in Boulder County showed evidence of infestation by the mountain pine beetle.
The most concentrated area of beetle-killed trees is in the southwest corner of the county, near Rollins Pass, where a 1,500- to 1,700-acre patch of dead lodgepole pines grows larger year after year.
Eldora fights back
The problem has become serious enough around Eldora Ski Resort that officials there began cutting down infested trees for the first time last week.
"It got to the point where we thought we had to do something," said Rob Linde, Eldora's marketing director. "This would be a very different place if the trees were gone."
Linde said the resort eventually will remove 300 to 400 infested trees from 250 acres of land. It also plans to spray insecticide on trees it wants to save.
Boulder County's Julian said despite the concentration of the mountain pine beetle around Rollins Pass, the rest of the county won't get by unscathed.
"This year, we think that we're going to see increased activity in other high-elevation areas, like Nederland, Ward and Allenspark," he said.
If the insect continues to drop down in elevation into the foothills — making a successful transition from lodgepole to ponderosa — Julian said it could have a lasting impact on tree stands closer to the county's populated areas.
That's because decades of fire suppression and other poor forest management practices in the lower foothills have resulted in the growth of dense mixes of ponderosa pine and Douglas fir. Where historically there were five to 30 large trees per acre, Julian said, there can now be as many as 3,600 spindly trees.
The result: thinner, younger and weaker stands that are a "smorgasbord" for insects and fire.
"The trees may not even be healthy enough to push the beetles out," Julian said.
_t220.jpg)
Photo by Sammy Dallal Brian Armstrong sprays high-value trees in Rocky Mountain National Park with a beetle repellent to help the trees fight off an infestation.
He said land management agencies and private property owners can take measures against the mountain pine beetle by thinning forests and spraying chemicals on select trees to keep the insects away — but ultimately, the beetles call the shots.
"All we can do is bring forests down in tree density, do prescribed burns and try to increase the health of the forest so the trees can fight these insects off," Julian said.
Keeping up appearances
The air-curtain burner, a Dumpster-sized fire box, eats around six tons of wood an hour.
Its flames, fueled by a steady stream of forced air, burn at nearly 1,500 degrees Fahrenheit.
Jeff Connor, natural resources specialist with Rocky Mountain National Park, uses a hammer and chisel to peel back the bark on a segment of ponderosa pine, revealing a tiny black beetle and a couple of squirming, squiggling beetle larvae.
Beetle facts
The mountain pine beetle has a one-year life cycle in Colorado.
It primarily attacks ponderosa, lodgepole, Scotch and limber pines.
Beetles attack live trees in late summer by tunneling under the bark.
They leave behind telltale, popcorn-shaped masses of resin, called pitch tubes, where they have burrowed into the trunk.
Beetles mate and form a vertical tunnel, or egg gallery, under the bark. Each pair produces about 75 eggs.
Eggs hatch and beetle larvae feed on phloem of trees over the winter.
They continue to feed off trees into the spring and transform into pupae in June and July.
Adult beetles emerge from trees in July and August and seek new living trees in which to feed and mate.
The beetles kill trees with the help of blue stain fungi. Spores of these fungi contaminate the bodies of adult beetles and are introduced into the tree during attack. The fungi give a blue-gray appearance to the sapwood.
Source: Colorado State University Cooperative Extension
On a cross-section, blue stain fungus colors the wood. Connor explains that the fungus is introduced to the trees by the beetles and works with the insect to clog the trees' phloem, or water and food transport system, killing the trees.
Within hours, the log the beetles are feasting on — along with the beetles themselves — will be dropped into the fires of the air-curtain burner.
Connor calls the tree-burning and beetle-killing exercise "sanitation."
The practice aims to remove and destroy several hundred beetle-plagued trees in "high-value" areas of the national park — such as campgrounds and trailheads — before the insects have the opportunity to hatch, bore their way out of the trees and fly off to attack new ones.
For high-profile trees not yet beset by beetles, the park uses an insecticide for protection.
While Connor acknowledges that both approaches are meant to keep the most visible trees in the most highly trafficked areas of the park looking pristine, neither does much to stop beetle infestation on a larger scale.
The area inside the park impacted by the mountain pine beetle increased from 887 acres in 2002 to 17,600 acres in 2006. Overall, Rocky Mountain National Park is 267,000 acres in size.
And while most of the beetles are on the west side of the park, an increasing number are appearing on this side of the Continental Divide — taking residence in both lodgepole and ponderosa pines.
"Activity is clearly increasing on the east side of the park," Connor said.
He pointed to an ocean of green trees on a faraway hillside beyond Glacier Basin Campground.
"You look out here and you can see the potential," Connor said.
Sea of red
On the other side of the Continental Divide, that potential has turned into reality. Entire valleys and mountainsides of trees in Grand Valley give off the reddish hue of death, victims of millions of voracious beetles.
Allen Owen, Boulder district forester for the Colorado State Forest Service, said he sees some disturbing parallels between Grand and Boulder counties.
"The forest (in Boulder County) has overaged lodgepole pines, the stocking levels are very high, and there's been a near lack of fire or forest management," Owen said.
But Owen said western Boulder County's hilly and jagged topography and higher diversity of tree species might put some natural brakes on the beetles' progress.
"We'll see red trees, but it won't be red from horizon to horizon," he said.
Sheryl Costello, an entomologist with the United States Forest Service, estimates it will be years before Boulder County is beset with the kind of beetle activity that struck Grand, Routt, Summit and Eagle counties.
"But that can definitely change," she said.
In any case, Costello said the county's high-elevation areas should see a "decent spread" this summer of the mountain pine beetle among lodgepole and limber pines.
Not that all of the beetle activity is bad, Costello said. Or unnatural.
Nor is it the first time Boulder County's trees have succumbed to the mountain pine beetle, which is native to Colorado.
As recently as the 1970s, the county went through a major beetle epidemic.
With lodgepole tree stands reaching old age throughout the county, it's not altogether surprising that they've become susceptible to an onslaught, Costello said.
"It's a natural process, these stands are getting to the end of their lifetimes, and the beetle is doing its thing," she said.
Photo by Sammy Dallal
Larvae of the mountain pine beetle on the trunk of a lodgepole pine at Rocky Mountain National Park.
Effects of climate change
Julian, with Boulder County Parks and Open Space, said that while beetle infestations are naturally occurring events, this one might be a bit different from ones that have struck in the past.
He said experts in the field are increasingly mentioning the effect that global climate change might be having on the state's current beetle epidemic.
Julian said more beetles are migrating to higher elevations than ever before. Where 9,500 feet was the stopping point for the mountain pine beetle in the past, the insects are now being found more regularly above 10,000 feet.
And warmer winters mean fewer severe cold snaps, which long has been nature's way of freezing larvae to death and stopping beetle epidemics in their tracks.
Julian said people and public agencies can and should still take measures to mitigate a possible beetle onslaught.
He said Boulder County has two to four years to thin tree stands and burn off undergrowth to make the forests in the foothills less hospitable to a massive beetle outbreak and leave behind less fuel for a massive wildfire down the road.
But he said there is only so much the county can do, given the history of fire suppression and the increasing numbers of people building homes in the mountains.
"It's taken 100 years to get to this point," Julian said. "We can't fix it in four."
Contact Camera Staff Writer John Aguilar at 303-473-1389 or aguilarj@dailycamera.com.
