Friday, April 07, 2006

How a northern forest can respond to warming

Here's another example of an ecosystem's inability to cope with sudden changes in a climate regime. Keep in mind that many of the global weather models assume that forest cover will act as a carbon sink, sucking CO2 from the atmosphere and mitigating its greenhouse effects. But dead trees give off CO2 as they rot, and the process of industrial logging creates lots of slash that often gets burned, yielding yet more CO2. Another problem is that living trees pump a lot of water vapor into the atmosphere, creating cloud cover which reflects sunlight (See albedo) and downwind precipitation. So fewer trees means more sunlight hitting (darker) ground, where it's absorbed, and less rainfall for ecosystem and human uses. There are some problems with assessing and modeling the balance between cooling via cloud reflection and warming by water vapor as a greenhouse gas. This conflict was a weak spot in earlier General Circulation Models (GCM) but has been one focus of recent model tweaks.

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'Rapid Warming' Spreads Havoc in Canada's Forests

Tiny Beetles Destroying Pines

By Doug Struck
Washington Post Foreign Service
Wednesday, March 1, 2006

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 infested an area three times the size of
Maryland, devastating swaths of lodgepole pines and 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. 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, said Carroll.
"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

Scientists with the Canadian Forest Service say the average temperature of
winters here has risen by more than 4 degrees in the last 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.

"It's depressing to see," said Steve Dodge, a British Columbia forestry
official whose office is along the Quesnel River. This town of 10,000 sits
in the heart of the province's vast evergreen woodlands. Steam billowing
from the kilns of a half-dozen sawmills and pulp plants enshroud the town,
which proudly calls itself the "Woodsmart City" in homage to the timber
industry that sustains it.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 up-and-down
channel, sometimes girdling the tree, crossing channels made by other

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. British Columbia is a buffet laid out before them. Years of successful battles against forest fires have allowed a thick concentration of old
lodgepole pines to grow -- a beetle feast that natural wildfire would have
stopped. "It was the perfect storm" of warmer weather and vulnerable old trees,
coupled with constraints that slowed logging of the infected wood, said
Douglas Routledge, who represents timber companies in the city of Prince

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 cold 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 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.

Pelchat is now spending his time trying to plan recovery through
replanting. In this area, a mature pine forest takes 70 years to grow.
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."

Ironically, Quesnel is booming now. The beetle has killed so many trees
that officials have more than doubled the allowable timber harvest, so
loggers can cut and haul as many dead trees as possible before they rot.
The icy roads are choked with giant trucks growling toward the mills,
loaded with logs marked with the telltale blue stain fungus.
In town, two sawmills and the plywood and pulp plants of the largest
company, West Fraser Mills, are "running flat-out," with shifts
round-the-clock, said Tom Turner, a manager there. He walked the catwalks
of a sawmill as whirling machines below grappled and twirled the offloaded
trees. Computers sized up each log, instantly figured the best cut, and
shoved it at furious speed through giant disk saws and planers to produce
lumber that rail cars would carry to home builders in the United States.
West Fraser is spending $100 million to upgrade the mill. Other companies
have added shifts and proposed new plants to make chipboard or wood-fuel
pellets. Property values in Quesnel are rising, rents are up, the local
shopping center is flourishing again and unemployment has dropped, said
Nate Bello, the mayor of Quesnel.

But the boom will end. When what people here call "beetlewood" is removed
or rots out -- and no one is sure how long that will take -- the forestry
industry "will be running at about half speed," Bello acknowledged.
He sees his chief challenge as figuring out how to convert Quesnel from a
one-industry town to something with a more diverse economic base. He and
city officials talk of attracting retirees and small, computer-based
businesses, and even of luring tourists to the area, despite the stark
industrial tableau of sawmills and pulp plants.

Some people in town say those are quixotic plans. "This town is going to
die," scoffed Pat Karey, 62, who spent 40 years at the sawmill. Other men
in the Quesnel cafe -- "Smokers Welcome" said the sign in the window --
nodded in assent.

"A mill job is $20 an hour, or $30 with benefits. The jobs they are talking
about bringing in are $8-an-hour jobs," said Del Boesem, whose runs a
business dismantling heavy logging machinery.

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