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Spotlight: Local forestry prepares for Mountain Pine Beetle to emerge from winter
Diego Syz
for Spotlight
Efforts to control the spread of the Mountain Pine Beetle are wrapping up in Alberta with the end of March and now scientists have to wait for this years’ beetles to burrow out from under the bark of pine trees in June to see how many there are this year.
Cutting and burning Alberta’s pine trees that are infected seems to be the best way of controlling the small beetle’s spread and government crews have been attacking infected pines between Slave Lake and High Prairie and to the west between Grande Prairie and Whitecourt.
“We have a few other sites to pick away at before July/August when the beetle flies away from the tree,” says Dale Thomas, with Alberta Sustainable Resource and Development, adding it will be a few years before the pine beetle controls can end in Alberta.
“I see it carrying on for a few more years, now that they’re in Alberta,” says Thomas.
The pine beetle came to Alberta in 2006 following a massive in-flight from British Columbia to Grande Cache in northern Alberta and Crowsnest Pass in Alberta’s southwest.
There was another big in-flight from B.C. in 2009 and the pine beetle appears to be adapting quite well to its new surroundings; it was just recently discovered it could live in Jack Pine, which is found across Canada’s boreal forest (coast-to-coast) and different from it’s usual favourite, the lodgepole pine.
A blue-stain fungus is introduced by the MPB when attacking a tree that clogs up and destroys the conductive tissue of the tree.
MPB larvae feed in the phloem (the tissue of the tree that channels liquids and nutrients through a tree’s system) and the combined repercussions of both the blue-stain fungus and larvae feeding can kill a tree in one month.
Some scientists at the University of Alberta say the ability to survive and infect Jack Pine trees could give the pine beetle the opportunity to spread from Alberta to the East Coast of Canada through the boreal forest.
“There will be 190,000 higher-risk trees controlled in the province,” says Brett Spady, the Mountain Pine Beetle information officer with Alberta Sustainable Resource.
“This is up from the approximately 150,000 trees controlled in the province last year,” adds Spady.
The gamble against the spread of MPB in Alberta is the $8 billion pure pine industry now at risk.
Six million hectares of Alberta pine forest are at risk of infection by MPB and containment is desired now, when the population of the beetle is comparatively low, opposed to facing MPB outbreaks capable of wiping out thousands of hectares in a few years, according to the Alberta SRD website.
Alberta has invested $255 million since 2006 (a combination of base and emergency funding) to control the spread of MPB in the province, says Spady.
The annual MPB population is difficult to control or predict because it is subject to the number of pine trees they can find to shelter their young in for the winter, fluctuations in winter temperatures and “The Healthy Pine Strategy”, which is a move by Alberta SRD to increase the amount of pine harvested to reduce the ability of MPB to spread.
“The province expects good MPB survival in 2011; however, a population survey to determine the relative over-wintering success will be completed in June,” Spady says.
“This survey will help to inform 2011-12 control work,” adds Spady.
To understand the talent for survival and the ability to infest of the MPB, one must start with the biology of the beetle.
MPB burrows holes under the bark of pine trees in fall to lay their eggs and in the winter the eggs hatch into larvae.
These larvae hold one of the great characteristics of the species to survive, because to last a winter in Alberta, each larva must be able to live through severe drops in temperature.
To do this the larva excretes glycerol which acts as an anti-freeze agent, protecting the larva to temperatures of -35 degrees Celsius, explains Dr. Maya Evenden, PhD. and associate professor at the University of Alberta’s Department of Biology.
Once late June or July comes along, the larvae create oval-shaped chambers beneath the bark and develop into fully mature beetles which take flight from the tree in mid-July to mid-August.
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