Research conducted at the University of Northern British Columbia has quantified the significant decline in wood quality in trees killed by the mountain pine beetle. The research was funded by the Government of Canada’s Mountain Pine Beetle Initiative and is one of the first studies that focus on the rate of deterioration and fall of lodgepole pine infected by the beetle in British Columbia.

Led by UNBC Forestry professor Kathy Lewis (pictured at left), the research team has determined that the greatest changes in wood quality occur within the first two years of mortality. These changes include significant declines in wood moisture accompanied by a large increase in the prevalence of blue stain, the number and depth of cracks in the wood, and rot at the base.  After this initial decline in wood quality, however, there is only minor additional degradation before the tree falls down.  Actual tree fall appears to occur later in central BC ( > 10 years) than in other areas where pine beetle research has been conducted. Researchers examined a total of 450 dead trees located in various areas southwest of Prince George.  By analyzing tree rings, the sample trees were cross-dated against live trees to precisely determine their year of mortality.  

“To reduce the impacts of the current and future mountain pine beetle outbreaks, it’s important to know the relationship between time-since-death and the factors that affect wood quality,” says Dr. Lewis., a 1996 BC Forester of the Year award recipient.  “We’re not saying that after two years the wood is of no use, but the changes in wood quality affect the range of wood products that can be manufactured and the technologies used for production. This information is vital to planning the timing and distribution of salvage harvesting operations to recover the greatest-possible value from the wood.”

The results were announced today in Prince George at a Beetle Research Forum hosted by Natural Resources Canada. The present mountain pine beetle outbreak in the central interior of British Columbia is considered the largest outbreak ever in North America. It is affecting an area in excess of 8.5 million hectares.