Two pieces of grim news this week indicate that the beetle infestation plaguing the pine forests of the Western Slope is likely to get far worse in the next couple of years.
First, reports from the Front Range indicate that the mountain pine beetle has, as expected, successfully crossed the Continental Divide and is now boring through trees in Fort Collins, Boulder, Greeley, Loveland, Berthoud and Windsor. Defying the notion that the beetles would only successfully propagate in dense lodgepole pines, the insects are colonizing Scotch pines and ponderosa pines.
“Mike Antolin, who lives in north Fort Collins, was shocked to see his stand of 70-year-old ponderosa pines … pocked with thousands of pitch tubes” — attacked trees’ defense mechanism — in early Sept., reports The Coloradoan’s Miles Blumhardt.
Then, the Boulder-based National Center for Atmospheric Research released preliminary findings from a study indicating that by wiping out huge tracts of forest, the beetles can alter local weather patterns – essentially inducing insect-caused drought conditions.
Forests cool and humidify the air, says Alex Guenther, the lead NCAR scientist on the four-year probe into the state of the forests under beetle assault. “In addition trees emit gases that form particles, particles starting points for cloud droplets,” Guenther adds.
“The expectation would be warmer and drier” conditions in the affected forest in the coming years. That sets off a vicious feedback loop: Warmer drier forests make better beetle sanctuaries, and more beetles kill off more trees.
Taken together, these developments seem to confirm the worst predictions about the beetle’s advance, which has been underway since the late 1990s. Every pine tree to the edge of the Great Plains could be gone in the next five years, though the devastation could be less severe east of the Divide.
Beetles claimed 500,000 new acres of trees in 2007, according to the annual aerial survey of Colorado’s forests, making the total kill 1.5 million acres.
Foresters are puzzled about how the beetle spread so quickly into Fort Collins, effectively hopping over the Poudre Canyon. Mountain pine beetles have a flight range of about a mile. One theory is that infested firewood imported from the Western Slope has brought beetle larva into the city. High late-summer winds could also have aided the migration.
“We’re all scratching our heads about the source,” beetle expert Dave Leatherman, a retired Colorado State Forest Service entomologist, told the Coloradoan.