2 March 2006Duluth News TribuneDough Struck
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, B.C., 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. 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 beetle 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," said Michael Pelchat, a forestry officer in Quesnel, 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."
The tiny beetle has always lived in high areas from Arizona to northern British Columbia, and occasionally populations have grown in limited outbreaks. In Canada, where the beetle's favored lodgepole pine thrives, it has been controlled by winters with early cold snaps or long killing spells of 20 degrees below zero. But for more than a decade, forestry experts say, the weather here has not been cold enough for long enough to kill the beetle.
Scientists with the Canadian Forest Service say the average temperature of winters has risen by 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.
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.
Surveys show the beetle has infested 21 million acres and killed 411 million cubic feet of trees -- double the annual take by all the loggers in Canada. In seven years or sooner, the Forest Service predicts, that kill will nearly triple and 80 percent of the pines in the central British Columbia forest will be dead.
Meanwhile, the beetle is moving eastward. It has breached the natural wall of the Rocky Mountains in places, threatening the tourist treasures of national forest near Banff, Alberta, and is within striking distance of the vast Northern Boreal Forest that reaches to the eastern seaboard.
"If that beetle is allowed to come any further, it will absolutely devastate our eastern slope forests," said Coutts, in Alberta. "If we're not prepared, it's going to infest all Alberta, Saskatchewan, Manitoba, and then northern Ontario in 20 years. This is the battlefront."
