The mountain pine beetle continues to spread throughout Jasper National Park, but at a slower rate, according to preliminary information gathered by the Alberta government and Parks Canada officials.
The news bodes well for pine trees in the park, which have been ravaged by the tiny beetles in recent years as they slowly spread eastward from British Columbia to Alberta.
“Our preliminary indications are that the beetle isn’t doing that well,” said Dave Smith, a fire and vegetation specialist with Parks Canada.
“What we’re finding is the beetles are attacking the trees and so far we’re not seeing a huge number of successful beetle brood,” he said, referring to the number of beetles that emerge as adults before moving onto the next tree to repeat their lifecycle.
In recent years, the number of infested pine trees in the park has surged from about 400 trees in 2012 to more than 6,000 hectares, according to the most recent survey by Forestry Canada.
“Alberta is the front line, that’s where the battle is being waged,” said Smith, stressing that the sample size is still too small to draw any concrete conclusions.
Every year Alberta Environment and Sustainable Resource Development works with Parks Canada to conduct two surveys to study the over winter mortality rate of the beetle in the park.
“You need 97.5 per cent mortality of all the beetle population to keep that population in check,” said Duncan MacDonnell, a public affairs officer for Alberta Environment and Sustainable Resource Development (ESRD).
“What you need to get mortality over the winter is 24 consecutive hours of -40 ambient air temperature, that’s -40 excluding the wind chill,” he said, adding that it’s very rare for the temperature to fall that low.
The survey will run until mid-June. Once it’s complete, the government will release its findings based on information collected across the province and Parks will work together with Alberta ESRD to create and implement a joint management plan.
The latest survey, based on data from the spring of 2013, shows mountain pine beetle has spread as far east as Rocky Mountain House and Slave Lake in the north.
MacDonnell said it’s too early to know the survival rate of the beetle population over last winter, but said previous surveys show the majority of beetle infestation in Alberta falls between Hinton, Slave Lake and Grande Prairie.
“If you connect those three points on a triangle that’s where the bulk of the beetle infestation is and that’s also the heart of the pine basket in Alberta,” said MacDonnell.
The first infestation in Alberta was in 2006 after a wind event blew a swarm of beetles into the province from B.C. That was followed by a second wave in 2009, said MacDonnell.
Currently more than one million hectares of pine forest is infested in Alberta out of a possible six million hectares, he said, explaining the government has already spent nearly $400 million fighting the beetle, which has cost the economy between $4 to $8 billion.
“You can’t put a price on clean air and clean water,” he said, “What happens when you have beetles destroy a forest is you upset the hydrological processes in that forest.”
As a result, he said, the pine beetle threatens not only traditional industries such as timber and tourism, but also the ability of nature to sustain both wildlife and humans.
“Mountain pine beetle is the greatest single threat to forest health in Alberta. It has been for 10 years and it continues to be,” he said.
It’s too early to know if Parks’ beetle strategy, which relies on prescribed burns and tree removal, is the primary reason the beetles’ eastward expansion into the park has slowed down, but Smith said he suspects it’s a combination of factors.
“A couple years ago we did a small study that showed that our spring and fall fluctuations that we get throw the beetles out of whack,” he said, adding that sometimes the males and females are unable to meet reducing their ability to procreate.
The beetle kills pine trees by burrowing under the bark and mining the phloem, the layer between the bark and wood of the tree. The beetles then lay eggs under the bark. After the eggs hatch, the grub-like larvae spend the winter feeding under the bark. The larvae pupate in the spring and emerge as adults from July to September before moving onto the next mature pine tree.
In addition to the beetle, which has a one-year life cycle, the species transmits a blue stain fungus during colonization. The combination of beetle tunneling and blue stain fungi disrupts the movement of water within the tree and rapidly kills it.
According to MacDonnell, there can be enough beetles in one tree to attack 10 more trees, allowing the species to grow 10-fold year-after-year.
While native to western Canada and the United States, the population has surged because winters are no longer as cold as they used to be and actions to suppress naturally occurring forests fires over the past 70 years have left an abundance of mature pine trees ripe for beetles to feed on.
To slow the spread of the beetle, Parks primarily uses prescribed burns to eliminate old growth forest that has not already been infested.
The idea is that by creating a firebreak any beetles that fly into the area will not be able to survive because there aren’t any healthy trees left for them to colonize.
“People often think when we talk about burning and beetles, we want to take forests that have beetles in them and kill the beetles—that doesn’t really work, but what does work is eliminating the habitat in front of them,” said Smith.
“It’s not the be all end all, but it’s a good barrier. Beetles will still continue to fly in there, but they’ve got nothing to keep them going.”
So far this year Parks has burned just over 100 hectares and expects to burn another 600 to 700 more.
The worst hit areas are in the west end of the park and along Highway 16 near Mount Robson Provincial Park.
“You don’t need to be a statistician to go and look at every dead tree in Mount Robson and know that’s where the beetles are coming from,” said Smith.
He said another major concern is the fire hazard left behind after the trees die.
As a result, Parks also uses prescribed burns to remove the threat and protect commercial interests.
“You end up with these dead trees that are basically like match sticks, they’re dry and we already know from experience in British Columbia, that wildfires in beetle-killed forests burn faster and with a greater intensity than normal fires,” said MacDonnell.
In town and in campsites, Parks has already removed 800 trees, including healthy pine trees that could become infested in the future.
To mitigate the loss, Parks transplanted about 1,200 trees last summer, mainly douglas fir, from areas where the trees may have caused a problem, such as along power line corridors.
For those who want to help protect pine trees in town, Smith said, people can purchase products that use synthetic verbenone to keep beetles away. It works by replicating a pheromone produced by the beetles that would usually indicate the tree is already colonized.
For information about fire and vegetation, contact Kim Weir, Parks’ fire communication officer, at 780-852-6169 or [email protected]
Paul Clarke
[email protected]
