Forester talks about enemies of local trees

It’s not easy being a tree in Central Oregon.

Ponderosa pine, lodgepole pine, grand fir, juniper, aspen, white fir, and larch face enemies that include humans (forest fires), weather, lightning and insects (disease).

Veteran forester Jack Barringer presented an overview of Central Oregon’s native trees and some of their problems to the Friends of Black Butte Ranch at a Thursday, March 10 session.

Focusing on insects, Barringer described the life cycles and potential damage insects such as the Ips beetle, mountain pine beetle, pine engraver beetle, west pine beetle, and pitch moth can do to a number of trees.

“We see the emergence of insects in the spring,” Barringer said.

Showing tree anatomy, he described how insects lay eggs under the bark and the larvae feed on the cambium and phloem layers of the living tree. This causes weakness and potential death of the tree.

“The different beetle larvae leave distinctive patterns as ‘fingerprint’ I.D.s of their species on the tree layers,” Barringer said.

The beetles gain an advantage in attacking weakened trees or invading downed trees, thus offering their larvae food and a better chance of reaching adulthood. These new adults can go on to infect other trees

Barringer favors judicious thinning to reduce stress on the remaining trees and improve their health.

“The thinning will increase oleo-resin pressure in these trees and help them to better block entry of insects,” he said.