A pine beetle infestation has devastated mountain forests across the West, but local forests have only been nibbled, not consumed, by the scourge.
The mountain pine beetle has been attributed as the cause of the death of thousands of lodge pole pine, limber pine and other species of pine trees throughout Colorado, Montana, Wyoming, Idaho, Utah, Oregon and Washington. In areas such as the north slope of the Uinta Mountains, the mortality rate of pines has been upwards of 75 percent, according to Kathy Jo Pollock, public information officer for the Uinta-Wasatch-Cache National Forest.
However, although there are many species of pines the beetles are attracted to in the mountains of Tooele County, the beetle population has been relatively low, said Steve Munson, group leader for the forest help protection staff for the Uinta-Wasatch-Cache National Forest.
“We have seen pockets of damage, but it’s from other types of beetles,” he said. “There’s really nothing significant — what we’d call endemic levels of activity, which is normal. Luckily the Stansbury Mountains and the Oquirrh Mountains don’t have the mortality rate we’ve seen on the north slope of the Uintas.”
The lower numbers of pine beetles locally are likely due to the comparative isolation of mountains in Tooele County, Munson said, which makes it harder for the beetle population to spread.
“Having it isolated as they are, it helps. Where we have a large, continuous landscape, they can keep moving. But those are isolated ranges, and it’s more difficult for them to move to those sites,” he said. “It’s not that you don’t have susceptible hosts there, it’s just that the beetles haven’t gotten there.”
The pine beetle population as a whole, too, appears to be on the decline. Munson said the long, wet, cool spring of 2011 could be the cause, since the beetles are much more susceptible to cold when they first emerge than later in the season. Alternatively, the decline could be simply because they have run out of enough food to feed their inflated population and are thus collapsing on themselves.
If the population continues to decline, he said, it is possible that Tooele County could escape the heavy, hungry concentrations of the insects altogether.
“It hasn’t moved into those mountain ranges yet, and it’s not that it can’t happen, but it hasn’t and it may not,” he said.
The spruce beetle, which has been a perennial and prolific problem throughout much of the state since the late 1980s, has not yet made its way to local ranges. However, he said, that is not to say Tooele County is out of the woods when it comes to tree-eating pests. Fir beetles, for example, are still a problem in Tooele County, though not to the levels of other types of bugs around the state and region. And the populations of beetles could grow significantly given the right weather conditions.
“At least in Tooele County, with our populations of other bark beetles, you may see an increase in activity if we go through a long period of drought, but right now they’re only at endemic levels,” he said.