Study: Forests hit by beetles can regenerate

Another study shows beetle epidemics are a natural part of the life cycle of western forests and don't need human intervention to recover.

Research conducted by CSU student, others eyes trees on RMNP's west side.

The needles might be brown, and the trees might fall, but the forests are not dead.

Even in some of the lodgepole pine stands most severely hit by the bark beetle infestation, there are enough surviving trees to regenerate the forest, according to a new study by CSU master's student Matthew Diskin, Colorado State University forest rangeland watershed stewardship assistant professor Monique Rocca and a team of others.

The study, which takes a close look at forest regeneration on the west side of Rocky Mountain National Park following the pine beetle epidemic, shows the beetle-ravaged forests could look different in the future, but many could fully regenerate in a few decades.

Many people talk about the brown lodgepole forests as if they are dead, but that's "absolutely false," Diskin said. "The forests are not dead. The brown canopies tend to hide the survivors in the understory."

What those copper-topped forests hide, he said, is a plethora of small pine saplings and even many fully grown lodgepoles, which survived the bark beetles.

Diskin used computer models to figure out how quickly those forests could regenerate without the help of humans.

"Nearly all the areas may recover the basal area within 40 to 100 years," he said. "The basal area is a measure of the stocking of the forest - how many big trees there are in the forest."

Some areas, he said, might regenerate more slowly while others might regenerate much more quickly.

"I think the findings of my study sort of paint this positive twist on what's happening with the epidemic," he said. "There are definitely some severe changes happening to these forests."

As some forests regenerate, Rocca said, lodgepole pine will remain the dominant species, while other forests will see other species such as spruce, fir or aspen become the dominant species.

Beetle-ravaged forests in wilderness areas, such as many of those at Rocky Mountain National Park, shouldn't be characterized as "devastated," Diskin said, because many of the forests will return to their prior verdant state without the help of forest managers.

Beetle-killed forests near homes and businesses, he said, are a different story.

"It is critically important that we ensure our infrastructure is protected," he said.

Diskin and his team presented his study, still being peer-reviewed, in March at the Rocky Mountain National Park 2010 Research Conference in Estes Park.