By: Fitz Hugh
Using prescribed burns to slow the spread of the mountain pine beetle is an expensive method that likely won’t work, according to at least one scientist who’s studied the beetle for the past 20 years.
Diana Six, a professor of forest entomology and pathology at the University of Montana, cast doubt on the effectiveness of Parks Canada’s plan to use fire to slow the spread of the beetle through Jasper National Park.
“It sounds like an expensive and potentially damaging method that probably won’t work,” said Six, who is the chair of the department of ecosystems and conservation sciences at the university.
She questioned how burning mature forests ahead of the beetle will slow the beetle’s spread, arguing history has shown the beetles have been able to jump entire mountain ranges.
Mountain pine beetle has always existed in Western Canada, but decades of fire suppression combined with a warming climate has left forests particularly vulnerable to the pest.
In the early 2000s, the beetle’s population exploded in British Columbia, affecting more than 40 million acres and devastating the province’s forestry industry.
Concerns about the beetle—which kill trees by burrowing under their bark, stopping the flow of nutrients—have escalated in recent years, as it makes its way from B.C. across Alberta.
“You might be able to slow it down by spending a lot of money, but it’s going to keep going,” said Six, adding models have predicted the beetle will likely spread across Alberta and the Boreal forest all the way to the east coast.
“It’s a very expensive losing battle that you don’t really have a long term hope of winning unless you actually go to the source that’s causing the problem.”
Six said using prescribed burns is a treatment for a much larger problem created by global warming.
Pine beetles can produce a kind of natural anti-freeze when they feel the cold weather coming on. This glycerol helps them survive the coldest months, unless a snap of extremely frigid weather hits. In the past those -40° C snaps were fairly frequent. But in today’s warming climate, they’re not.
“Insect outbreaks, not just mountain pine beetles, but a lot of the other bark beetles, they respond to underlying conditions and those conditions are climatically driven so you can thin, you can cut and burn, but you’re not changing underlying conditions you’re just treating some of the conditions.
“It’s like having cancer and thinking if you take an Aspirin that that’s going to do something because it makes you feel better for a little while; you have to go to the actual conditions to have an affect.”
Parks did not respond for comment, but during a public address last week, Alan Fehr, superintendent of Jasper National Park, said the agency is working closely with the Canadian Forest Service, the Government of Alberta and the municipality to complete a mitigation strategy for the pine beetle.
He said part of the plan will likely include using prescribed burns to help slow the spread of the beetle, although the exact plan has not yet been published.
Parks lost funding that allowed it to undertake measures to control the mountain pine beetle in 2008 and subsequently populations in the park have been slowly rising.
That rise increased significantly in 2013, when the number of infested pine trees jumped to 1,900, from a previous average of anywhere from 100–400 trees. In 2014 the problem got even worse, when Parks saw so many infested trees it stopped counting them individually, and instead started counting hectares of infested trees.
In 2014, Dave Smith, a fire and vegetation specialist with Parks, told the Fitzhugh, that by burning large swaths of the forest with prescribed burns, the beetles have no place to live when they propagate in the spring.
Prescribed fires have been used in JNP for more than a decade, not only to fight the spread of the mountain pine beetle, but to restore forest health and biodiversity. They’ve also been used to create a firebreak around the community to help protect the townsite and other facilities.
Instead of using prescribed burns to fight the beetle, Six said its time to consider other techniques, such as understanding tree genetics to help forests adapt to their changing environment.
“What I’m trying to do is look at ways, at least in the short term, we can try and help our forests adapt so that they don’t just go into catastrophic failure,” said Six, who has been researching why certain trees appear to be resistant to the beetle.
To do her research she has been taking core samples from infested trees and comparing them to samples from trees that appear to be resistant to the beetle.
“After the beetles go through an area and have caused a lot of mortality there always appears to be some survivors that come through the whole thing unscathed,” she said.
“What we’re trying to figure out is what is it about those survivors that has allowed them to escape and not be killed.”
She said she hopes that through her research she can determine if the trees that survive have a different genetic make up and could therefore be used to help create a future generation of trees that are better suited for the warming climate.
“When we go out and look at the woods all those trees look exactly the same to us, they’re like clones, but they’re not,” said Six.
“They’re incredibly genetically variable, the beetles can see that, we can’t, but with genetic tools we can go out and see which trees are most drought tolerant, which ones are going to be beetle tolerant and then maybe use that information to inform our management so that we can avoid doing things that might be counter to adaptation.”
By: Fitz Hugh