Foresters’ work to stave off beetle achieves ‘stunning success’

  • Published
  • By David Edwards
  • Air Force Academy Public Affairs
U.S. Air Force Academy, Colo. --  What's black and light and dreaded all over?

For Diane Strohm and her co-workers, the answer is the mountain pine beetle, a tiny creature that is the arboreal equivalent of Attila the Hun.

Strohm, a forester and natural resource planner for the 10th Civil Engineer Squadron here, has seen plenty of examples of the destruction wreaked by the beetle: 4 million acres of pine forest in Colorado alone.

Her determination to keep the adversary at bay has prevented the stands of verdant conifers at the Academy from joining that list. Like any good war plan, her approach combines offensive and defensive maneuvers.

"It's a wellness program, just like with a person," Strohm said. "It's a long-term strategy to keep our forests healthy. (The beetles are) endemic to the ecosystem, so there will always be some of them there. We can't totally eradicate them."

In 2007, survey teams roamed the Academy grounds in search of trees harboring pine beetles. They found 280, which were removed and taken miles from the nearest pine tree.

Surveys done in subsequent years showed steady reductions, so the number of trees requiring removal has dropped each year and is now down to a mere five.

Strohm estimates that if the Academy had ignored the problem and not removed the trees, the beetle would have killed 10,000 ponderosa pines by last summer.

The mortality numbers rise exponentially because of a multiplier effect, said Jim McDermott, who was Strohm's predecessor at the Air Force Academy. Infestation in one tree permits the beetle's spread to three other trees, so one becomes four, four becomes 16 and so on.

According to the Colorado State University Extension website, nothing practical can be done to save a tree once it has fallen victim to mountain pine beetles. The options on offense are limited.

The defensive part of the Academy's strategy against pine beetles involves forest thinning and spraying. About 250 acres of forest are now thinned annually, up from 100 acres before the program. Individual trees at high risk for infestation receive the spray.

Put all that together and what you get is "stunning success," as Strohm says. So stunning, in fact, that the program won an Air Force-level award earlier this year and was mentioned in a Centerviews magazine article documenting Air Force conservation efforts.

Other agencies across the Rocky Mountain West have inquired about the secrets to the success of Strohm's efforts. Financial backing from the federal government has helped: The Forest Service has contributed between $50,000 and $90,000 a year specifically for the program.

"For the most part, the Academy allows Diane to have the money to manage the forest properly," McDermott said. "That's to their credit. A lot of places are so big and the prevention is so costly, they have to just watch the trees die."

McDermott said the Academy's tactics are textbook prevention, and he follows the same strategy in helping Woodland Park avoid the pine beetle pestilence.

Nature can aid the cause, too. The pine beetle's trail of destruction elsewhere in Colorado was blazed mostly through lodgepole pines, which are thinner than the ponderosas found at the Academy and therefore more susceptible to the insect legions and more easily ravaged by invasion.

A prolonged intense cold period -- ambient temperatures of minus-30 degrees for several days -- will decimate the pine beetle population more effectively than anything else, Strohm said. There were a couple of days with those conditions this past winter, but the cold snap didn't last long enough.

Instead of cooperating, lately nature has been working against the tree defenders.
"The drought has greatly exacerbated the problem," Strohm said. "When the trees get affected by drought, their defenses are down. If the drought would lessen, our strategy's effectiveness would be greatly enhanced."

Parched trees are vulnerable to lots of threats, not just mountain pine beetles. Right now, Strohm and her colleagues are dealing with the less destructive but more plentiful ips beetle.

Nevertheless, the mountain pine beetle remains the primo pest. It's the bug that keeps foresters up at night. During the day, it is the source of constant vigilance and efforts to ensure that mixed ownership of lands in its territory doesn't benefit the beetle.

"I really think the key to our success here is that we have a large enough area that is under our control," Strohm said. "It's an optimal opportunity to manage for this beetle." Much of the adjacent land is owned and managed by the Forest Service, so the Academy can depend on a partner that has just as much at stake.

Knowing that the mountain pine beetle isn't just a temporary visitor, Strohm and her colleagues must resign themselves to its presence. They plan to continue doing all in their power to keep the balance tilted toward the Academy.

Beetles beware.