KEEPING the pedal to the metal

Alberta is working hard to keep its foot on the gas in battling the mountain pine beetle, but the beetle keeps knocking on Saskatchewan’s western door.

By Tony Kryzanowski

The latest forestry research shows that the mountain pine beetle has not yet crossed the border from Alberta into Saskatchewan except for small pockets in the extreme southern Cypress Hills area—but in other areas, it is knocking on Saskatchewan’s door with attacks identified on the Alberta side of the federal Primrose Air Weapons Range, located north of Cold Lake.

While attacks have been detected, there is no indication that the beetle has actually become established.

What’s concerning about its presence in this location is that this is the western edge of the Canadian jackpine forest that stretches from Alberta to Newfoundland. The most current scientific data shows that the beetle can survive and thrive with jackpine as its host. All that seems to be presently holding it back from proliferating is that the jackpine forest is more northerly as compared to the lodgepole pine resource, in a region that tends to experience colder temperatures for longer periods of time. In other words, the current jackpine forest is not within the beetle’s historical range, and sustained periods of -40 degree Celsius weather thankfully takes its toll on beetles.

However, global warming could change all that. Its impact on beetle spread has already been demonstrated in Alberta where over the past two decades, the beetle has become established further north than it has ever appeared before. The challenge is that typical harsh cold snaps on the Prairies are not as frequent as they used to be, according to climate data collected in Alberta, showing a gradual winter warming trend over the past 80 years.

Insect traps installed by the Saskatchewan government on its side of the border of the Primrose Air Weapons Range have so far yielded no beetle presence—but Katherine Bleiker, Research Scientist in Entomology at the Canadian Forest Service Pacific Forestry Centre, says that Saskatchewan’s surveillance is also like trying to find a needle in a haystack.

Bleiker recently gave a presentation on the reassessment of the threat of the eastward spread of the beetle in Canada during a podcast hosted by the Canadian Forest Service. The information she presented was based on the third risk assessment for the beetle infestation conducted for Canada in 2018 and published in 2019 as part of the National Forest Pest Strategy. The most current risk assessment data from 2018 shows a lot more pine at risk in western Saskatchewan than previously thought.

“There are a lot of things that we don’t know about how the mountain pine beetle is going to behave in jackpine, but I think the old axiom that more big trees are better will at least hold,” Bleiker says.

She confirmed that the beetle’s current infestation in Alberta is beyond its historical boundaries.

“In central and northern Canada, the historical range has been limited to west of the Continental Divide,” she said, except for areas in extreme southern Alberta. The Continental Divide is essentially the Rocky Mountain range.

“Multiple times in the 2000’s, we had beetles that dispersed over the Rockies on upper atmospheric winds and deposited into northeastern British Columbia as well as Alberta,” she added. The biggest initial migration occurred in 2006, when the beetle became established outside its historical range, and triggered the first emergency risk assessment conducted in 2007.

“The conclusion of that risk assessment was that the mountain pine beetle would persist in Alberta, but its spread was anticipated to be very slow,” says Bleiker. “This was largely because the climate was not that great for it and there was relatively poor connectivity of host pine, but there was no biological barrier that would prevent the spread and make it go extinct.”

In other words, the geographic transition in Alberta from lodgepole pine to jackpine was not seen as a biological barrier.

However, the 2014 risk assessment from data gathered in 2010-2011 changed a lot of thinking within the scientific community studying the challenge of the beetle’s march over the Rockies. That assessment concluded that the spread of the beetle in Alberta between 2006 and 2010 was much faster than anticipated, host conductivity was not as much a constraint as originally thought, and jackpine was actually under a bigger threat than expected.

Bleiker says it is still unclear exactly how attractive a host jackpine is to the beetle because there have not been opportunities to conduct stand-level research on this relationship—but it would be fair to conclude that the beetle would be at least as receptive to jackpine as a host as all other non-lodgepole pine species. Research has shown that the beetle is able to use nearly all North American pine species to a lesser and greater extent as a host.

Bleiker’s presentation was a reminder of the danger presented by the spread of the beetle. Although the beetle cycle has been on the wane in central B.C. for the past decade, its devastation to that area’s lodgepole pine resource is still making its presence felt in permanent sawmill closures due to an unprecedented loss of commercial wood fibre, and catastrophic fires fueled by the remaining standing and fallen dead pine logs.

According to a study published in 2015 in an academic publication called Forestry: An International Journal of Forest Research, by 2012, 53 per cent of the merchantable pine in the B.C. Interior had been attacked by the beetle. The decimation of the merchantable pine resource will result in a cumulative value loss of over $57 billion, or a 1.34 percent drop in British Columbia’s GDP from 2009 to 2054.

While its impact is still being felt in the B.C. Interior, all eyes are now on the eastern side of the Rockies in Alberta, where the beetle continues to have a significant impact on both the Banff and Jasper National Parks, as well as commercial timber resources in places like Hinton, Edson, Whitecourt, Slave Lake, and Grande Prairie. The latest research shows that during a large outbreak, which is currently underway in most of these areas, the beetle can migrate anywhere between 100 to 300 kilometres when it takes flight.

“There have been reports of beetles caught at 900 metres above the ground so we do know that they are capable of getting into the airstream at that level, which is probably going to see them transported much further distances,” says Bleiker.

The question now is whether Alberta’s beetle mitigation strategy, not supported by the federal government except for mitigation efforts in the national parks that many have described as too little/too late, will be sufficient to stop the beetle from significantly entering and thriving in the commercially important jackpine forest. The province is currently spending $30 million per year to fight the beetle, adding $20 million over four years to the effort last October. The Agriculture and Forestry Department says the money will be spent on more ground surveys and control efforts on 83,000 hectares.

Bleiker says that the Mountain Pine Beetle Response Plan released in 2015 based on considerable input from Dr. Barry Cook, Research Scientist with the Canadian Forest Service headquartered in Sault Ste. Marie, Ontario, “identified eastern Alberta as the best battleground to slow the spread east.”

“We know the recipe for successful control, which is early detection, aggressive control and sustained control over time,” says Bleiker. “You basically can’t take your foot off the gas until the population is suppressed.”