Spruce Bark Beetle

Picture shows beetle tracks throughout the woody part of the tree below where the bark once covered.

Spruce Bark Beetle infestation cycles have been recurring in northern forests and the Kenai Peninsula for hundreds of years, typically around 50-year cycles. These beetles attack large mature spruce trees eventually killing them. In the 1990’s the Kenai Peninsula had a particularly devastating infestation, aggravated by unusually warm summers. The 1990 infestation decimated the spruce forests in the whole region including here at Twin Rivers Wilderness.

When the thick spruce forest on Jack Easterday’s 480-acre homestead was overtaken by beetles in mid-1990, he opted to sell the property to Buffalo Timber company, since the parcel was large enough to justify its own logging operation to harvest the standing dead spruce. Most other local landowners just endured standing dead spruce trees which eventually fell, and completely reorganized the local forests into meadows and alder thickets and new immature forests, and sometimes to eventually better views. Here at Twin Rivers, the generally level upper areas were logged, but the slopes were not logged, and you can observe the contrasts when you hike from the upper-level areas with healthy standing trees and some moss-covered stumps, to the side slopes where travel is very difficult among fallen trees everywhere commingled with the new growth trees. Exercise care and caution when hiking off-trail on the valley slopes–you will be stepping and climbing over an expanse of fallen timber.

References:

Spruce Bark Beetle Outbreaks on the Kenai Peninsula, Alaska. Forest Ecology and Management, June 2006.