For the second winter in a row, pine beetle numbers in southwest Alberta, including Kananaskis Country, have dwindled.
The overwinter survival of the beetles in the region, however, was not matched through the rest of the province, with the northwest area seeing high population survival and central Alberta remaining stable.
“What we have here is a good news/bad news story relative to mountain pine beetles, " said Minister of Sustainable Resource Development Mel Knight. “This is a serious issue for Alberta and a high risk for the boreal forest east of us as well. "
Knight said the plan to address the pest, in his opinion, has been relatively successful but noted Mother Nature also plays a part.
This past winter was easier on beetles than the previous one, which saw high rates of mortality due to significant temperature fluxuations in the spring of 2010.
“I suspect in the south a combination of cold temperatures and no snow on the ground has resulted in less beetles surviving, " said Allan Carroll, University of British Columbia associate professor for the department of forest sciences.
He noted mountain pine beetle is a native species of western North America.
He said the current outbreak began in the mid '90s in B.C. and the numbers have been increasing dramatically since then.
Major in-flights of the beetle into this province occurred in 2002 and 2006 and Carroll said the trees they have been attacking here have been highly suitable as food sources with climate conditions also playing a part.
“With increasing climate change things will improve for beetles, " he said.
Carroll stressed the importance of early intervention and action when populations are small.
“We hope we can keep things going long enough to drive populations down to endemic levels, " he said. “Populations in B.C. are in decline and soon that risk of (in-flights) will diminish and disappear. "
Senior forest health manager Mike Undershultz said the numbers are used to determine where aerial surveys in August will be done.
Undershultz warned that even though low survival of beetles was seen in southern Alberta, “we are not out of the woods yet ".
“There is still a risk of in-flights from British Columbia as populations are high on that side of the border, " he said, adding populations can also erupt when conditions are favourable.
While the beetles’ tree of choice has been the lodgepole pine, it has also been attacking jack pine, putting forests to the east of Alberta at risk.
Knight said one goal is to keep the beetle from spreading in that direction. The province has invested $300 million so far, with $30 million budgeted for this year while the federal government has provided $18 million.
Duncan MacDonnell with SRD said the strategy in southwest Alberta has been aggressive and will continue.
But, while two years ago 30,000 trees were removed, this year that number dropped to 160 for the region.
, which includes Spray, Kananaskis, parts of the Bow Valley, Sibbald Creek area, Cypress Hills and Crowsnest Pass.
