23 Mar 2015

“Meet The Beetles”, our friends to the south, the San Juan Forest Service.

0 Comment

Making plans to deal with the spruce beetle

This is   follow-up story to the meeting that the San Juan Forest Service held last week, “Meet The Beetles”.  The expected outcome of the meeting was that everyone gained a baseline understanding of the epidemic…

‘They’re predators, just like a pack of wolves’
By Ann Butler Herald staff writer
The spruce beetle, which has significantly damaged the Rio Grande National Forest, is rapidly making inroads into the San Juan National Forest.
On Tuesday, the U.S. Forest Service held a meeting to kick off a planning process on how to deal with the beetle and the trees it kills while feeding.
“We’re not coming to you with a proposal of what we want to do,” said San Juan National Forest Supervisor Kara Chadwick. “This is designed to give us all a common understanding of spruce-beetle dynamics and the current epidemic and to discuss what we can do about it on the ground.”
In recent years, beetles have damaged 23,000 acres in La Plata County, and about 209,000 of the roughly 500,000 acres of the San Juan National Forest.
U.S. Forest Service entomologist Tom Eager gave the standing-room-only crowd in the Vallecito Room at Fort Lewis College a primer about the beetle, one of many predators attacking Colorado forests, along with defoliators and the mountain-pine, western-pine, pinyon-ips and Douglas-fir beetles.
“These are predators, just like a pack of wolves hunting a wounded moose,” Eager said. “For them, a blow-down of old spruce is like a McDonald’s hamburger stand.”
The beetle, which has a “better sense of smell than a bloodhound,” primarily attacks Engelmann spruce, he said, although a large stand of blue spruce by Cascade Creek has been hard hit in this area.
Female attack beetles are the advance scouts, seeking older spruce that are generally distressed in some way, perhaps blown over in a wind or enduring a drought. When they find a prime candidate, Eager said, they send out a chemical to attract other female and male spruce beetles. The beetles burrow under the bark of the spruce, lay their eggs and feed on the phloem layer, which is a sugar, he said.
“People say, ‘They’re insects, why don’t they just freeze in the winter?’” Eager said. “They convert that sugar into glycol, which is antifreeze. They’ve been in a symbiotic relationship with the spruce for millennia, and they’ve survived many cold winters.”
The key to stopping the cycle, he said, is for an extremely cold, dry winter, so the beetles’ trees aren’t insulated by snow.
“We haven’t seen one of those in a while,” Eager said. “And the way things are going, we may not see one anytime soon. Climate change is the wild card here.”
While a number of ways to deter or kill spruce beetles have been developed to work on small areas or individual trees, he said, there’s nothing yet at that will work at a scale of the landscape in the San Juan.
The Forest Service will hold open houses at the three districts within the San Juan National Forest – Dolores, Columbine and Pagosa Springs – sometime in the next couple of months, Chadwick said, and may plan a field trip up to Wolf Creek Pass or over into the Rio Grande National Forest so people can see the effect of the beetles on the ground.
Laurie Swisher, the forester who manages the vegetation database on the San Juan, said only about 20 percent of the areas in the San Juan National Forest are appropriate for forestry management techniques. The rest is either in wilderness or special management areas or too inaccessible or fragile for any work to be done. They’re looking for input from the public on how to handle the areas where they can do mitigation and restoration work.
“Our first priority will be safety, so making sure that where people go, like trails, roads, campgrounds, and things like power lines, cannot be hurt or affected by falling trees,” she said. “Then we want to look at the potential for salvage logging of the dead trees. We could use the timber sales receipts to put back into restoration where we did the logging.”
Logging can be a touchy word for environmentalists, but it may allow for a more diverse forest inventory that would be more resilient to future insect attacks, Eager said.
“One of the reasons we’re worried about saving old spruce is a human value,” he said after being asked if aspen, which are often the first trees to grow in destroyed areas, might create the largest aspen forest in the country here. “We’re worried our grandkids aren’t going to see the same kind of forests we did. But this is not all doom and gloom. Aspen come roaring back into these areas like a freight train, and you’re right, for tourism, that could be a jewel.”
There are a lot of numbers in the spruce-beetle story. Here are a few key numbers that explain what’s happening:
In 2014, 480,000 acres in Colorado were affected by the spruce beetle.
Of the 13.2 million acres managed by the U.S. Forest Service in Colorado, more than 75 percent are out-of-bounds for any forestry management between being in protected wilderness areas or being located on slopes that are too inaccessible or fragile for any management practices.
Of the 1.8 million acres in the San Juan National Forest, about 209,000 acres have been affected by the spruce beetle.
Only 20 percent of the 209,000 acres in the San Juan National Forest are eligible for any forestry management techniques.
The average spruce beetle has a two-year lifespan.
A female attack spruce beetle lays between 80 and 150 eggs after boring below the spruce’s bark.
About 20 percent of female attack spruce beetles attack and lay eggs in more than one tree.
Up to 125 other organisms, including mites and fungi – a whole series of parasites and predators – enter a spruce with the beetle.
The average flight range for a spruce beetle is about 1 mile, but in the summer, they often are picked up by warm air currents and can travel much further.


« « THE BEETLE THAT’S CHEWING UP AMERICA | PLP Executive Committee Meeting, Thursday, April 2, 2015 » »