Beetle attack hits Utah forests

Mother Nature can be a beast, as those who love the Utah's forests are discovering.

About 2.2 million acres of the 3.5 million acres of pine, fir and spruce forests in the state are moderately to highly susceptible to bark beetle attack, according to "Utah Forest Health Report," assembled by the Utah Department of Natural Resources with data through 2001.

"Because of generally high stand densities, greater than 90 percent of Utah's forested landscapes currently have a moderate to high risk of catastrophic wildfires," adds a 2003 update, "Forest Health in Utah."

About 10,000 acres to 30,000 acres of aspen, mostly in the south, are undergoing a mysterious die-off, among 1.6 million acres of aspen forests in Utah, says an aspen expert.

"The beetles are expanding" on Wasatch-Cache National Forest, said Wayne Padgett, ecologist for that forest. It's not just the pine beetles; it's also fir beetles and spruce beetles.

Much of the eruption is because humans have been successful at controlling forest fires for many decades. "We've got what tend to be older trees on the forest," he said. These older, weaker trees are more susceptible to attack by beetles and other stressors.

"We've created this huge fuel load now. These large old pine forests are susceptible to beetles. ... We're looking at probably larger fires than we've seen historically."

The pine-beetle infestation is moving along the north slope of the Uintas, from Evanston, Wyo., along the Mirror Lake highway. They have reached Utah, and some are destroying trees east of Kamas, he said.

Besides the trees' age, a six- or seven-year drought "added stress," he said. "The fuels are dry. The trees have a low, low percent of moisture in them."

Some trees along the highway are to be taken out, because less tree density can reduce the vulnerability of the trees.

Although humans have intensified the impacts by fire suppression, this is a natural process, Padgett said.

Projects to manage bark beetles have been proposed on almost every national forest in Utah, from pesticides to spraying insect pheromones to thinning stands and removing dead trees, said Liz Hebertson, a forest-health expert with the agency's regional office in Ogden.