How Science Can Help to Halt The Western Bark Beetle Plague

For residents of the Rocky Mountain region of the United States and Canada, global warming is not an abstract concept. It is a reality they confront every day in the form of tens of millions of acres of pine and spruce trees that have died as a result of beetle infestations spawned by a hotter, drier climate.

Few people know as much about this forest plague as University of Montana entomologist Diana Six, who is working with colleagues to understand why the genetics of some individual trees enable them to survive even as whole forests around them are turning brown and perishing. Six says the infestations are now happening worldwide, with major outbreaks in Africa and Europe. But the worst impacts to date are in the North American West, where bark beetles are spreading quickly into new territories and attacking high-altitude tree species that were previously unaffected.

In an interview with Yale Environment 360, Six explains the root causes of the beetle infestations, discusses why U.S. Forest Service policies may be making the problem worse, and describes why the best hope for Western forests will come from the trees’ capacity to genetically adapt to a new climate regime. Science, she says, can help support this natural process of evolution by mapping genetic markers in trees that survive the insects, so forest managers can breed trees that are better able to cope with future beetle onslaughts. “The only way that we can help our forests in the long term is to strengthen their genetic abilities for adaptation,” says Six. “We have to consider some radical new ways of thinking.”


When trees die, water slows

Mountain pine beetle populations have exploded over the past decade due to warmer temperatures and drier summers, and these insects have infected and killed thousands of acres of western pine forests. Researchers have predicted that as trees died, streamflow would increase because fewer trees would take up water through their roots.

A recent study by University of Utah geology and geophysics professor Paul Brooks and his colleagues in Arizona, Colorado and Idaho, found that if too many trees die, compensatory processes kick in and may actually reduce water availability. When large areas of trees die, the forest floor becomes sunnier, warmer and windier, which causes winter snow and summer rain to evaporate rather than slowly recharging groundwater.

The bad news is that the loss of so many trees may not help alleviate the long-term drought in the West as many have hoped. The good news is that researchers can use the new understanding of forest water cycle to manage healthier forests that are more resistant to drought but still supply water to agriculture and cities downstream.


Pine Beetle wreaks havoc in region

Ryan Zapisocki swings a leg over his skidoo, fires up the engine and rides into the forest. The snow is melting and a warm breeze is blowing through the pines, causing them to sway slowly against each other. Some needles on the trees are tinged red, others, deep auburn. He slows as he arrives at his destination: a gathering of trees marked with ribbons. These are the ones that will be cut and burned come this February.

“There are heavier infestations in the west near Jasper,” he says, leaning forward in his chair and pointing to a map on the wall. “The pine beetles in this region are coming from that direction.”

Zapisocki is a quality inspector who started checking surveyed areas last week. He and a crew of four have been contracted by Alberta Parks and Environment to help deal with the Mountain Pine Beetle.


Good news about mountain pine beetle in Saskatchewan: There still aren't many

There's some promising news on the mountain pine beetle's presence — or lack thereof — in Saskatchewan.

The insect has destroyed millions of hectares of lodgepole pine in British Columbia and Alberta, and there were worries that it could move further north, where there are a lot of jack pines.

Rory McIntosh, Saskatchewan's forest entomologist and pathologist, says they have found no trace of the dangerous bug in the northwest part of the province for the second straight year.


Mayor concerned pine beetle could increase wildfire risk

Jasper’s mayor is concerned the mountain pine beetle, which is spreading eastward through the park, could increase the community’s wildfire risk.

Mayor Richard Ireland raised his concern during a meeting with Parks Canada on Oct. 16. The mayors of Hinton and Yellowhead County, as well as representatives from the forestry industry, also attended the meeting.

“As the forest turns increasingly red and dead west of us, our primarily concern locally is the safety of the community from wildfire,” said Ireland, who took an aerial tour of the park last week to see the beetle’s impact first hand.