Drought-stressed trees in Alberta could see more mountain pine beetles

As Alberta conducts annual aerial surveys of its forests, the province’s forest expert says she expects they’ll start to see the signs of drought — including more mountain pine beetles.

This year’s surveys, which started on Aug. 15 and run until Sept. 15, come after extremely dry weather hit the province throughout the summer.

“Drought has a variety of effects on the forests and obviously on the insect population,” said Erica Samis, manager of forest health and adaptation with Alberta Agriculture and Forestry. “When a tree is drought stressed, it can’t withstand attacks.


Drought makes B.C. timber vulnerable to hungry bark beetles

A B.C. government entomologist in Kamloops says the current drought across most of the southern half of the province is stressing timber across the Interior.

Lorraine Maclauchlan says photosynthesis drops when water is scarce, making trees more vulnerable to damaging attacks from insects such as bark beetles.

The beetles bore through bark and munch on the nutrient-carrying layer just underneath, so Maclauchlan says trees use resin as a defence, pumping out the sticky fluid in order to flush away attacking insects.