The mountain pine beetle has ravaged the forests of British Columbia and continues its eastward march into Alberta. In its wake, it leaves dead forests, an increased risk of fire, and mill closures in forest communities.
Beetle affected forest in northern Alberta – Photo Credit: Government of Alberta
The beetle isn’t just a problem for forestry towns, though. It can also have major impacts on the quality of our air and water. In fact, the beetle was a contributor to forest fires in the summers of 2017 and 2018 that caused air quality alerts and emergency room visits throughout western Canada. Moreover, destruction of the forest resource undermines an important filtration source for our drinking water. When a forest burns, not only does it lose the ability to filter drinking water, it also contributes large amounts of ash and sediment into our water. Removing these materials is very difficult and expensive.
Smoke from forest fires in British Columbia hangs over Edmonton in the summer of 2017
The mountain pine beetle attacks trees by laying eggs underneath the bark. Older trees make ideal beetle habitat. Their thicker bark provides insulation and biological defences in older trees tend to be weaker.
An adult pine beetle tunnels into a mature pine – Photo Credit: Government of Alberta
Once beetles have colonized a tree, they emit a fungus from a specialized pocket in their mouth. The fungus prevents the tree from absorbing water and nutrients.
Cold weather has an impact on the success of each infestation. Prolonged periods of cold temperature kill pine beetles. Warming winters due to climate change have greatly decreased the number of days that are cold enough to kill the beetle and caused large expansions of the beetle’s range.
Healthy pine trees are also able to defend themselves from small-scale infestations by giving off a toxic resin. However, weaker, older trees or those that are overwhelmed by a larger infestation succumb to the beetles’ attack.
A pine tree defends itself by emitting a toxic pitch – Photo Credit: Government of Alberta
Once a tree has been overwhelmed, its needles begin to turn red. Within the tree, fungus stains the sapwood with a blue tinge. Ultimately, the tree will lose all of its needles. The wood will begin to dry out and lose all merchantable qualities. At this point, the dead and dry tree is a substantial fire hazard.
Beetles use each successful infestation as a means to disperse further. Each July and August, adult beetles attack new trees. The beetles can fly up to five kilometres per day. Strong winds and updrafts can increase the beetle’s flying distance substantially.
Beetles have been proven to be able to attack a number of different pine species. This means that there is a very real risk that spread could devastate Canada’s pine forests from coast to coast.
Blue stain in a beetle attacked tree – Photo Credit: Government of Alberta
Government and industry in Alberta have made an effective stand against the beetle. Aggressive surveying work has provided intelligence that is used to map the beetle’s location and ensure the most efficient allocation of resources.
Once surveys are complete, different containment strategies are applied. In areas of light infestation, this often involves felling and burning infested trees. Areas of larger infestation require more intensive containment strategies including controlled burns and larger scale harvesting. The role of industry is to identify large stands of older pine that are at risk of infestation. These stands are then given priority in the harvesting sequence. After harvest, new trees are planted. Younger pine is much less susceptible to the beetle.
This strategy has been effective at limiting the beetle’s spread in Alberta. Even though damage to our forests has occurred, it is on a far smaller scale than the widespread outbreak that has killed 50% of the merchantable pine in British Columbia.
A plane surveys a beetle infestation in Alberta’s forests – Photo Credit: Government of Alberta
Containing the beetle in Alberta has given provinces and communities that are further east time to prepare by updating firefighting procedures, making plans for watersheds, and harvesting susceptible stands.
But Alberta’s strategy is expensive. Over the last decade, the Government of Alberta has invested over $500 million in containment work. Forestry companies have also invested heavily by changing plans and updating equipment to process beetle affected wood.
Alberta needs help from the rest of Canada to continue this invaluable work. You can lend your voice to the effort by calling or writing your Member of Parliament and asking for additional federal resources to be spent on pine beetle control work in Alberta.