Article Contributed on: 3/14/2006 9:15:33 AM
They buzz through Colorado’s mountain forests, seeking out the weak and wounded, the drought ravaged or old aged. Like a virus, they drill inside a host, multiply by the dozen, and resume flight, leaving in their path a trail of dead in the thousands, maybe even millions.
Except the prey aren’t people, they are trees, and the predator, the western bark beetle, is a quarter-inch bug that is threatening to devastate Colorado’s ski areas, national forests and backyards.
The western bark beetle has long been a key figure in forest ecosystems throughout western North America. A natural defense against over-dense forest and aged timber, the beetles are a normal part of forest ecosystems in sustained numbers.
But scientists say that in the last decade environmental factors and man-made changes have contributed to several species rising to epidemic levels across the Front Range. If not contained, the beetles can kill millions of trees in one season, living entire forests lifeless
With a heavy dependence on healthy trees, ski areas statewide are being forced to manage beetle populations and do what they can to protect key forests. Trees are needed not only to hold snow and provide mountain aesthetics, but also to block wind from tearing across runs.
Steamboat Ski Resort identified the growing beetle populations eight years ago and began a joint effort with the city of Steamboat, the U.S. Forest Service, the ski area and the chamber of commerce to suppress numbers of the spruce and mountain pine beetles.
“Nobody is trying to annihilate the beetle because they are part of the ecosystem, but when they threatened key areas and certain aspects of the forest, we started getting involved,” said Lyn Halliday, ski area director of environmental affairs.
In 2004, the resort decided to remove 400 infected trees and sell them through a timber sale. The resort also has managed the population by setting pheromone traps that trap and kill the bugs, and by peeling bark off some trees to kill beetles.
“Were doing really good at keeping the spruce beetle population down, but of course you don’t want to stand up and declare a success until you have consecutive years. As far as the mountain pine beetle, they are really gung-ho all across the state,” Halliday said
Winter Park Resort in Grand County lies in prime mountain pine beetle country because of its abundance of lodgepole pine. The resort first noticed a large presence of the beetle in the winter of 2004, and since has identified 120 infected areas.
To combat any mass spreading, the resort cut down and peeled the bark from 260 trees while thinning out 5000 trees. Roads can’t be plowed up the mountain, so most of the trees had to be pulled out by helicopter, costing the resort $9 million.
“We are not doing this to build a chairlift or something, but only for environmental reasons. We have to do the best we can with what we have,” said Winter Park environmental coordinator Doug Laraby
Like Steamboat, Winter Park has sold timber and also reinvested the trees into new trail signs and maps, Laraby said.
While ski areas are doing their best to manage outbreaks, specialists said that the pine beetle is naturally tough to cope with, and that several environmental factors have created the epidemic.
“The beetle has the uncanny ability to reproduce very fast under good conditions and in various ecosystems,” said William Jacobi, a professor of plant pathology at Colorado State University.
Pine beetle epidemics naturally occur in cycles, and right now Colorado is in the climax of what should be a four- to six-year cycle, said research entomologist José Negrón, a specialist in bark beetles.
Negrón said that several factors have contributed to the severity of this epidemic.
Drought conditions, defined by the government as a period of insufficient rainfall for normal plant growth, have hindered Colorado’s forests for the past seven years and created an abundance of weak and damaged timber. The combination of the drought and already surging numbers of pine beetles has set the stage for record numbers of tree mortality in the coming years.
“The mountain pine beetle is always with us, but because of the drought and oldness of the forest, we basically have ‘the perfect storm’ for the beetle to go through large acreages of forest,” said Bob Sturtevant, a forestry extension specialist at CSU. “Right now we believe there are more beetles in Colorado then we have ever seen, at least since before Colorado was first settled.”
Outside of the environmental factors, Sturtevant said that growth in Colorado’s mountain areas has exaggerated the beetle’s presence, hindering efforts to slow the beetle. In the past workers would have cleared out large areas of trees to prevent the beetle from traveling long distances, but now it has become an unacceptable method because people don’t like to see clear cuts, Sturtevant said.<
“It is like the hurricane in New Orleans. If the city wasn’t there it would not have mattered as much. It is a problem of people being in the high country- a new forest will start naturally but now we have to manage more,” Sturtevant said.
While mass thinning, pheromone traps and peeling are some steps ski areas take to prevent breakouts, Sturtevant said individual homeowners should use preventative spray on high-value trees, and look for small holes drilled into the bark of trees. If the trees are dying and it’s possible to identify the bugs inside the tree, cut them down before the beetle can fly to other trees.
When talking about the future of the beetle in Colorado, Halliday said heavy snowfall this winter is helping to end the drought, but it is very difficult to say where the numbers will go.
“The best-case scenario is that they are going to die off and go back to their normal levels. Worst case, well that’s what we all are trying very hard to stop. We’ve lost some trees, but we just have to stay ahead of the game with good management,” Halliday said.
Sean McDonald is a journalism student at the University of Colorado.