A NEW BEETLE BATTLE in B.C.

By Jim Stirling

A long and frigid winter gripping the forests of north central British Columbia would be a huge bonus. But it’s more likely a forlorn hope, than a realistic possibility.

Sensibly, therefore, the forest industry coalition working toward containing an expanding spruce bark beetle infestation in the region is concentrating its efforts on factors and initiatives it can control in its continuing battle with the effects of a consistently warming climate.

Aerial surveys of the Omineca region during the summer of 2016 were backed by GPS and on-the-ground surveys. They confirmed the regional spruce beetle outbreak is continuing to increase in size, reports Heather Wiebe, Omineca spruce beetle project manager and resource manager with the B.C. Ministry of Forests, Lands and Natural Resource Operations based in Mackenzie, B.C. About 210,000 hectares of forest have now been damaged by the spruce beetle, according to the 2016 surveys compared with about 156,000 hectares in October 2015. Sections of the Prince George and Mackenzie forest districts are the hardest hit by new beetle attack.

A continuing cycle of warm springs, dry summers and warm winters are contributing factors to the spruce beetles’ growth. Those climatic factors are what’s influencing the beetles’ traditional peak and valley population cycles to population surges and a shift from normal endemic levels to epidemic proportions.

A further climate-related factor influencing spruce bark beetle populations in the forests is an increase in windstorms and the blowdowns they create. The phenomenon can be a mixed blessing: blowdown of mature trees can create a preferred environment for the spruce beetle. Site specific falling of mature spruce to act as trap trees is part of the containment strategy underway in the Omineca. When full of beetle larvae, the trap trees are removed for ‘hot’ harvesting. A felled spruce tree can be 10 times more successful in attracting spruce beetles than a standing stem, relates Wiebe.

The spruce beetles’ habitat preferences are further recognized and accommodated by licencees and their log harvesting contractors working in and around infected spruce stands. Decking patterns at roadside are changing. Larger spruce stems—the beetles’ preferred hosts—are being placed at the bottom of the deck. They are then shaded by smaller spruce positioned on top. “It’s like an umbrella”, says Wiebe.

The umbrella helps maintain a cooler environment for the host spruce underneath and that, in turn, inhibits beetle flight. Sixteen degrees Celsius (in the canopy) is the ‘flight time’ signal for spruce beetles. Fortunately for containment strategies, spruce beetles typically don’t fly the distances of the mountain pine beetle, for example, in their quest for new hosts to infest. And equally fortunately, spruce forest stands in the region are more patchy in distribution, and not comparable to the vast contiguous and even-aged stands that compounded the devastation caused by the mountain pine beetle epidemic.

“We received the raw data from the 2016 aerial surveys about a month earlier than we had previously,” Wiebe relates. That proved very helpful.

Timing is everything in putting together the critical elements for an effective beetle containment plan. But that said, timing is also a moving target. “We’re getting our conventional trap trees down in April, about three weeks earlier than before.” But the strategy has to be tempered by the maximum attractiveness of the beetles’ pheromones: too early, and they’re less effective, notes Wiebe.

The forests ministry, industry and partners like a public advisory committee in the beetle containment efforts don’t religiously follow a one size fits all control prescription.”We’re looking at each area uniquely and applying the appropriate beetle management system,” she points out. That might mean sanitized logging, a trap tree program, both or neither. It depends more on the specific circumstances within each small ecosystem, adds Wiebe.

Non-timber guidelines have been developed through the forests ministry to help log input from those quarters into an area’s management plan.

Wiebe says from the time the spruce beetle population increases were first noted in 2014, efforts have been taken to keep the range of land users and the general public informed and involved in what’s being undertaken to control the outbreak. The interest levels—like the stakes—are high. There is considerable concern in forestry- dependent communities throughout the B.C. Interior about the short and mid-term timber supply implications in the wake of the devastation caused by the mountain pine beetle epidemic. It’s a given that annual cuts will be decreased, with some areas being harder hit than others. A protracted beetle assault on mature spruce forests, as well, would simply exacerbate an already serious timber availability situation for many communities.

Part of that larger picture and a continuing commitment to cooperative involvement, were reasons behind the organization of a two-day spruce beetle summit held October 2016 in Prince George. One of its objectives was to bring together people who lived through the last major spruce beetle infestation in the 1980s to contribute the best known group wisdom to the present situation, explains Wiebe. The summit was attended by about 115 people, mainly representing the forest industry, ministry and academia from areas across the province. The spruce beetle numbers are on the march in several B.C. regions for similar combinations of changing climatic factors. “The summit helps ensure we are up to speed as we go forward,” she adds. “We need to continue pulling together in the same direction.”