Provincial crews pushing back on pine beetles
Monday, Mar 18, 2013 12:58 pm
Provincial crews battling the mountain pine beetle will know this spring whether years of work to prevent the pest from spreading through Alberta’s southwest foothills has worked.
Duncan MacDonnell, Alberta Environment and Sustainable Resources Development spokesperson, said aggressive work to track the number of pine beetles in the province’s southwest corner and to destroy infested trees has helped control the bug’s population.
The bug moved into the Kananaskis and Crowsnest Pass areas more than a decade ago and the spread threatened the pine tree population in the foothills.
However, there were so few infested trees last year provincial crews didn’t take on work targeting the beetle in the area.
“There were not enough trees to do sampling on to make the results scientifically valid,” said MacDonnell. “We’d gone from removing 30,000 trees a couple years ago to being down to, at that point last year, we has 32 infested trees that we knew of south of Highway 1.”
Officials will know this spring how affective their work has been when they conduct winter mortality surveys in the southwest mountains and foothills for the first time in two years. The survey will show whether their numbers have risen and how many were able to survive the mild winter.
MacDonnell said temperatures across the province didn’t drop to levels low enough to kill the bugs. An extended period of -40°C weather is needed to kill the dormant pine beetle during the winter.
“You’ve seen the winter we’re having out there which isn’t really a winter,” he said. “We don’t know what we’re going to have this year until after we do the mortality surveys.”
However, a late cold snap in the spring could also help to kill off a number of the bugs because the beetles are less cold-weather hardy in the spring.
For several years, provincial crews have taken to the air by helicopter in the fall to look for tell tale red trees infested by pine beetles and are now dead or dying. Personnel are then sent in on the ground to scour the surrounding trees looking for any that have signs they are infested as well. They then remove the individual trees during the winter months when the beetles are dormant.
Crews then head back to infestation sites in the spring to survey by removing sections of bark from trees to determine the number of living and dead beetle larvae.
“That gives you an indication of what the population dynamic is,” said MacDonnell.
He said the focus of the battle against the beetle in Alberta has shifted north.
The other front in the war against the beetle is in a triangular area in the west-central part of the province, between Grande Prairie, Hinton and Slave Lake. That infestation started in 2006.
“The removal of trees there, to this day are numbering in 100,000 trees plus,” he said.
He said they aren’t resting on their laurels in the southwest because the situation could still change.
“We continue to keep a watch on it and we’ll take out every infested tree we see,” he said.
He said there could be some pockets of beetle populations that survived the winter. As well, there is also the risk of bugs in B.C. making their way across the border. While the beetle population in B.C. peaked in 2011 and is dropping, he said it will take several years before their numbers bottom out.
“There are still plenty of beetles attacking trees on the B.C. side of the Rockies, they just haven’t crept through the passes,” he said.