An outbreak of the spruce beetle in the Omineca region north of Prince George could be a harbinger of things to come if the conditions that brought it to the fore remain in place in the coming years, according to a University of Northern British Columbia professor.
Like its cousin, the pine beetle, deep cold is one of the insect’s biggest enemies, so the recent series of “almost Okanagan-like” winters in this region has done little if anything to halt the bug’s progress, Dezene Huber, a professor in UNBC’s ecosystem science program told The Citizen.
Unlike its cousin, the spruce beetle prefers fallen trees and thanks to some major blowdowns, probably brought on by the more unpredictable and severe weather that comes with climate change, they’ve been getting an abundance of those, Huber also noted.
“We’ve been able to control spruce beetle generally speaking when it flares up in Canada and the U.S. over the years but every time it happens it’s a new story, especially in a shifting climate, so who knows what’s going to happen this time, necessarily,” Huber said.
“But it’s better to be on it than to just assume it’s the same old normal because in a lot of ways we’re heading into a new normal.”
Through a recent provincial survey of spruce stands, officials discovered that the area the spruce beetle is covering in the Omineca has increased 20 fold since 2013 and now sits at 1,560 square kilometres, nearly five times the size of Prince George.
The B.C. Ministry of Forests, Lands and Natural Resource Operations have announced $1 million in new funding for an aggressive control campaign. And forest companies are also working together to develop management plans.
To access the spruce stands, old roads and bridges that haven’t been used since the pine beetle infestation, which took out more than half of the province’s pine inventory, have been reactivated.
In areas set aside for wildlife or where harvesting is uneconomic, “trap trees” are being set out. They’re live trees that are taken down and left to draw in spruce beetle from the surrounding area and, before the larvae can mature into a new generation, the trees are taken away and milled.
Huber said it’s an effective tactic that’s been used for centuries.
“They’ve been known to work well in the past in other situations, including here in B.C.,” Huber said.
Both types of beetles belong to the same genus, dendroctonus which means tree killer. But there are differences that call for different tactics to contain the respective outbreaks.
In addition to preferring downed trees, spruce beetles don’t fly as far – they’ve been likened to a “flying tank.”
Spruce stands also tend to be patchier and, when you look at the map of the current outbreak, “it’s like a little bit of measles across the Omineca,” Huber said.
But if the populations get large enough, the spruce beetle will go after standing trees, he noted. Moreover, while they generally require two years to complete their life-cycle, things have been so good many are needing only one, he also noted.
An outbreak in the Bowron that began with a major blowdown in the mid-1970s eventually led to a decision to remove 15 million cubic metres of green attacked timber between 1981 and 1987. It was enough to build 900,000 single-family homes, noted Ralph Cozens in an online case history of the outbreak. At the peak, 700 truck loads of logs were coming from the Bowron every day, leading to a clearcut so large it could be seen from space.
“Clearcutting works, definitely, and it’s one of the tools in the manager’s tool box, but it’s not necessarily the tool that needs to be used every single time,” Huber said. “You don’t pull out a hammer every time you need to screw in a light bulb, sort of thing.”
Ministry of Forests, Lands and Natural Resource Operations spokesman Greig Bethel said the possibility of a repeat of Bowron is “non-applicable to the current situation.”
“According to ministry staff, many factors that led to the ‘Bowron clearcut’ have changed since the 1980s – i.e. the size of cutblocks, site preparation, expected retention and impacts from warmer temperatures, among others.”
Huber said greater knowledge accumulated over the years not only of the spruce beetle but of the mountain pine beetle could also work to our advantage when it comes to containing the outbreak.
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