Pine Beetles Likened To ‘Silent Forest Fire’ In Canada
Pine Beetles Likened To ‘Silent Forest Fire’ In Canada
2 March 2006
published by news.tbo.com
QUESNEL, B.C. — Millions of acres of Canada’s lush green forests are turning red in spasms of death. A voracious beetle, whose population has exploded with the warming climate, is killing more trees than wildfires or logging.
The mountain pine beetle has devastated swaths of lodgepole pines, reshaping the future of the forest and the communities in it.
“It’s pretty gut-wrenching,” said Allan Carroll, a research scientist at the Pacific Forestry Centre in Victoria whose studies tracked a lock step between warmer winters and the spread of the beetle. “People say climate change is something for our kids to worry about. No. It’s now.”
Scientists fear the beetle will cross the Rocky Mountains and sweep across the northern continent into areas where it used to be killed by severe cold but where winters now are comparatively mild. Officials in neighboring Alberta are setting fires and traps and felling thousands of trees in an attempt to keep the beetle at bay.
“This is an all-out battle,” said David Coutts, Alberta’s minister of sustainable resource development. The Canadian Forest Service calls it the largest known insect infestation in North American history.
U.S. Less Vulnerable
U.S. Forest Service officials say they are watching warily as the outbreak has spread. The United States is less vulnerable because it lacks the seamless forest of lodgepole pines that are a highway for the beetles in Canada. So far, U.S. officials say, the outbreaks have been mostly in isolated clumps of remote wilderness areas of northern Washington.
“It’s a rapid warming” that is increasing the beetles’ range, Carroll said. “All the data show there are significant changes over widespread areas that are going to cause us considerable amount of grief. Not only is it coming, it’s here.”
“We are seeing this pine beetle do things that have never been recorded before,” Michael Pelchat, a forestry officer in Quesnel, said as he followed moose tracks in the snow to examine a 100-year-old pine killed in one season by the beetle. “They are attacking younger trees and attacking timber in altitudes they have never been before.”
Scientists with the Canadian Forest Service say the average temperature of winters here has risen more than 4 degrees in the past century. “That’s not insignificant,” said Jim Snetsinger, British Columbia’s chief forester. “Global warming is happening. We have to start to account for it.”
The result is a swarm of beetles that has grown exponentially in the past six years, flying from tree to tree. The advance is marked by broad swaths of rust-red forest, the color pines turn before they drop all their needles to become ghostly grey skeletons.
A Deadly Battle
In an attack played out millions of times over, a female beetle no bigger than a rice grain finds an older lodgepole pine, its favored host, and drills inside the bark. There, it eats a channel straight up the tree, laying eggs as it goes. The tree fights back. It pumps sap toward the bug and the new larvae, enveloping them in a mass of the sticky substance. The tree then tries to eject its captives through a small, crusty chute in the bark.
Countering, the beetle sends out a pheromone call for reinforcements. More beetles arrive, mounting a mass attack. A fungus on the beetle, called the blue stain fungus, works into the living wood, strangling its water flow. The larvae begin eating at right angles to the original channel, sometimes girdling the tree, crossing channels made by other beetles.
The pine is doomed. As it slowly dies, the larvae remain protected over the winter. In spring, they burrow out of the bark and launch themselves into the wind to their next victims.
At the province’s Ministry of Forests and Range in Quesnel, forestry officer Pelchat saw the beetle expansion coming as “a silent forest fire.” He and his colleagues launched an offensive to try to stop or at least delay the invasion, all the while hoping for low temperatures. They searched out beetle-ridden trees, cutting them and burning them. They thinned forests. They set out traps. But the deep freeze never came.
“We lost. They built up into an army and came across,” Pelchat said. Surveys show the beetles have infested 21 million acres and killed 411 million cubic feet of trees – double the annual take by all the loggers in Canada.
