Boulder Creek was roaring down the mountainside north of Silverthorne as we bushwhacked along an abandoned trail bursting with blooming yellow balsam, blue delphinium and acres of dandelions in the clearings of the White River National Forest.
The sun bore down hard on the dusty ground and the hot, dry wind left our throats parched, our lips cracked. We finally found a small mound of melting snow on a north-facing slope deep in the forest, and Charley, the Labrador retriever, buried his nose eagerly into the refreshing, dirty canine snowcone.
We were above 10,000 feet. It was still May, but in the high-altitude forest, it might as well have been July.
Welcome to colorful Colorado.
Better enjoy it while it lasts.
One of the unmistakable effects of global warming is right here in the forests of Grand, Routt, Jackson, Eagle and Summit counties, where the bark beetle infestation has turned whole mountainsides from green to rusty brown.
Entomologists studying the insects for the U.S. Forest Service have found that the beetles have adapted from a two-year life cycle to a one-year cycle in response to the warmer climate. Cold temperatures at high altitudes used to require the beetles to survive two winters to complete their life cycle and reproduce. As a result, huge numbers of the vulnerable among them would die off in the second winter, keeping their population in check and helping the forest survive.
But since the 1990s – the warmest decade of the millennium, according to the United Nations Intergovernmental Panel on Climate Change – the beetles have evolved to complete their life cycle in one year and now reproduce at a breathtaking rate.
At the same time, the forests have been stressed by drought and are in no condition to rally the defenses necessary to fend off even a normal bark beetle attack.
So the critters are winning.
All that beetle-kill you see from your SUV as you speed along Interstate 70 is known in the wildfire vernacular as fuel. And all it will take is a lightning strike on a summer afternoon to turn the forest into an open-air incinerator: Nature’s surefire method for exterminating bark beetles.
“We’re monitoring weather and fuel conditions on the ground,” said Rich Homann, fire division supervisor for the Colorado State Forest Service. “Right now, the dead fuels are drier than normal, and there is an abundance of them. Conditions are right for large fires.”
That’s measured forester-speak, sure, but it’s also a warning of a real scorcher of a wildfire season on the horizon, one that could be as bad as 2002, when 600,000 acres burned in Colorado in the worst fire season in the state’s history.
Even the healthy snowpack in the northern and central mountains last winter offers little in the way of consolation. The record-setting spring heat and below-normal precipitation have produced a wicked early snowmelt, leaving the soil parched as the earth’s natural moisturizer evaporates or rushes prematurely toward the Colorado River.
“The number of acres burned this year already has exceeded the number burned in all of 2005,” Homann said.
The worst conditions are along the Front Range and across the whole southern portion of the state, he said. “We’re trying to prepare for the increased risk.”
The first instinct of a forester is to remind forest users to be careful setting campfires, tossing cigarettes and driving cars with catalytic converters across dry brush. People living in the woods are urged to clear combustibles away from their homes and to be careful with barbecue grills.
It’s all good advice.
Homann knows the fires still will burn, though, if not this year, maybe next or the one after that, and whole swatches of forests will disappear. They’re too hot, too dry, too infected to go on like this.
He knows, too, that the pine forests with the blue delphinium and the yellow balsam will recover when the spring rains and summer thunderstorms and cold winters return.
And they will someday. Someday.
Diane Carman’s column normally appears Sunday, Tuesday and Thursday. She can be reached at 303-820-1489 or dcarman@denverpost.com.
