Battling
Bugs Forest diseases can ravage timber. So far, nothing of the proportion of the mountain pine beetle threatens coastal forests. Foresters are intent on keeping it that way.
DOUGLAS-FIR BARK BEETLE
Dendroctonus pseudotsugae
Foresters like Stefan Zeglan, Coast Area Forest Pathologist, had hoped to discover whether this white pine might be a strain resistant to white pine blister rust. After it was attacked by bough harvesters, they’ll never know.
WHITE PINE BLISTER RUST
Cronartium ribicola Western white pine used to be one of the most productive tree species in western North America, but the introduction of the white pine blister rust in 1900 prevented it from being considered an acceptable species for regeneration in BC. Rust spores infect new needles, eventually causing a canker to develop in the bark of the host. If the canker girdles the main stem, the tree dies. Branch pruning can protect some trees; without it, most white pines die. Several trials are underway around Powell River and on Texada Island, trying to grow trees that are resistant to white pine blister rust. In some of these area, though, bough pickers have destroyed candidate trees.
After the windstorm of 2006 (the one that devastated Stanley Park), forest companies couldn’t get to all the blown-down wood fast enough. The Douglas-fir Bark Beetle was faster. Attracted to the dead wood, the beetles attacked the downed wood. Then they started on the standing timber. Fortunately, the loggers weren’t very far behind the beetles, and, in infected stands, they would drop a truckload of logs, wait for the beetles to move in, then pick up the logs and dump them in the ocean, where the beetles would die. It seems to be working. “We have set up a series of funnel traps again this year to monitor bark beetle numbers. They seem to be trending downwards in the past two years, which is a good thing,” says Blake Fougère, Forest Stewardship Officer for the Ministry of Forests.
ROOT DISEASE Phellinus weirii
Laminated root rot is the most prominent root disease of Douglas-fir on the Sunshine Coast, although Armillaria root disease (Armillaria ostoyae) takes it toll, too. While treatment options are limited, areas with root rot are often targeted for earlier harvest, then foresters use various strategies to prevent the root disease from seriously infecting the new stand. FF FERNS & FALLERS • PAGE 33