SILVERTHORNE, COLO. — The pristine mountainsides of the Gore Range, across the lower Blue River Valley, have taken on a new color lately.
The red hue stretching like fingers through the normally dark-green forests is a telltale sign – even from a distance – of the devastation being wreaked by a tiny culprit, about the size of a match head: the mountain pine beetle.
This color is becoming increasingly common in northern Colorado and throughout the West as the tiny beetle lays waste to vast swaths of vulnerable lodgepole pine forests, typically monocultures of trees that are weakened by drought and are all about the same mature age – perfect fodder for the voracious beetle.
The destruction, which has killed millions of lodgepole pines in Colorado alone, will alter the look of the landscape and is a risk to local economies that depend on mountain tourism. It's also prompting a major response because of concerns about the threat to life and property from falling trees, as well as the increased risk of wildfire.
"The forest is resetting itself on a landscape scale," says Jim Maxwell, a US Forest Service spokesman for the Rocky Mountain region. "It's not like they've come in like a plague of locusts: They're residents of the forest, and in normal times, they perform a benefit to the forest by thinning out weak and sickly trees. But now it's an epidemic.... It wouldn't be nearly as much of a concern as it is if we didn't have communities built up into the forests and local economies dependent on the forest."
Pine beetles – and other bark beetles that have been attacking trees such as spruce and subalpine fir – are hardly new to the ecosystem. What's made them so potent this time around, say scientists, is a combination of factors: warmer winters that have helped the beetles multiply, drought that has weakened the trees' natural defenses, and, primarily, millions of acres of less-diverse forests that are all maturing about the same time.
Pine beetles typically attack trees more than 80 or 100 years old and more than six inches in diameter. Many Western lodgepole forests are reaching that state simultaneously, since huge areas of forest were cut down in the late 1800s for mining operations, and in recent years, fire has been suppressed. The result is pine-beetle devastation on a scale that's never been seen in the recorded history of the West.
A report earlier this month from the Colorado State Forest Service determined that about 660,000 acres of lodgepole forests – more than 40 percent of Colorado's total – were infested in 2006, and about four times as many trees were killed per acre than in the previous year.
The scale is such that nothing can be done to change the outcome significantly. Over the course of the next few decades, experts say, large tracts will turn red, then gray. Eventually the dead trees will fall and new ones will spring up.
In the meantime, though, coalitions including the Forest Service, Bureau of Land Management, National Park Service, local governments, homeowners associations, and ski areas are working to minimize the damage and risk.
"If we're going to do anything in a meaningful way, it's going to take everybody working together on this," says Don Carroll, head of the Northern Colorado Bark Beetle Cooperative.
His cooperative covers a five-county area and just broadened to include five more. In areas around important infrastructure and homes, they're working to remove dead trees that could lead to fires, develop a local biomass industry that can use the harvested wood, and spray in very small, high-priority areas.
In Summit County, officials have developed a wildfire protection plan that has identified 18 areas where the county will try to thin and harvest forest.
"We're not going to change it on a landscape basis, so we've been concentrating on management where it'll do the most good," says Rick Newton, the ranger for the Forest Service's Dillon Ranger District, as he points out dying stands of trees surrounding a hospital and high school.
His ranger station also hands out DVDs and answers questions from concerned tourists. "Human beings aren't used to seeing landscape changes like this," he explains.
A high priority is developing industries that can use the low-quality pine wood and help finance an increasingly expensive operation. Even industries with more resources, like ski areas, are realizing the potential expenses involved.
After spending $500,000 two years ago to thin forests and fly dead trees out by helicopter, Winter Park Ski Area is now focusing on spraying some 30 acres, removing trees directly near trails, and educating skiers.
Still, officials are hopeful when it comes to the long-term outlook. Having learned from this current cycle, they say, they'll work hard to encourage more diverse forests.
"We'll try to break up the age class structure in the forest and get special diversity back – similar to what existed in the past," says Wayne Shepperd, a recently retired silviculturist with the Rocky Mountain Research Station. "We live in an interesting time for forest ecology."