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Dust Bowl times 10 •The 1930s Dust Bowl was widely considered a plague in the Rockies, when beetles exploded and killed trees. Likewise, a handful of dry years in the 1970s denuded mountains. But Six believes this is the worst outbreak ever - perhaps 10 times the Dust Bowl's death count.
It's impossible to compare today's killing zones to the Depression era in direct terms, because foresters now fly airplanes with satellite-guided charting tools instead of drawing crude maps from personal observations made on a mule's back. But scientists, including at the Forest Service's Rocky Mountain Research Station in Utah, agree there has been nothing like this in recorded history.
Tree-ring analysis dating to the 1800s fails to show any signs of a greater collapse. But Barbara Bentz, an entomologist at the station, is working with other researchers studying ancient lake deposits to gauge whether prehistoric disturbances were on this level.
"Climate has changed in the past," Bentz said. "Certainly what's happening now is big, but I don't want to say it hasn't happened before."
Six calls the beetles "my organism" and, like other scientists, she speaks in endearing tones when discussing the insects. They're native to the forest, after all, and through time they have a role in opening patches for shade-intolerant shrubs and seedlings.
But she believes nature is out of whack. The outbreak continues to grow despite two wet La NiÃ±a years, which might ordinarily break the cycle. A dry winter this year would help the attack mushroom further.
On the Bitterroot, foresters are trying to get ahead of the damage but only in places that are practical. One is Lake Como, a blue-water alpine beauty south of Missoula that draws 100,000 visitors a year.
On a ridge above the lake, where Forest Service founder Gifford Pinchot personally targeted trees for the region's largest timber sale in 1906, a commercial logging crew thinned 65 acres last year. Those trees had come back as a monolith, in contrast to what had been a blotchy, fire-thinned forest during the previous two centuries.
Now, the thinned area is chock-full of frosty-blue lupine cones and dispersed trees awaiting their fight with beetles. Standing in hot daylight, Sturdevant said the openings are their own repellent. Cool moisture on the breeze helps beetles communicate by pheromones.
But that was the easy part - 65 acres by a good dirt road. Bitterroot officials want to treat 1,500 acres around the lake, and that could take years.
There aren't enough forest employees to judge environmental impacts, area silviculturist Cheri Hartless said. "There's a lot of people that [must] walk this ground to make sure everything is kosher," she said. "And then, if there's no [timber] buyer, it won't happen anyway."
At the Lake Como Campground, crews have soaked great ponderosas with Carbaryl. At another campground, too close to the East Fork of the Bitterroot for spraying, they have stapled two pheromone patches apiece to the shady north sides of trees every 40 feet. The shade keeps them from drying out, and the spacing ensures full coverage of the scent that tells beetles to stay away.
It costs the government $7 a tree to buy the pouches in bulk, and that is impractical for the broader forest. But crews are buying time for special places in case a cooler cycle returns to slow the beetles.
For now, it's all anyone can do.
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