Researchers at the University of Northern B.C. in Prince George say the pine beetle, which has destroyed about 40 per cent of the province's lodgepole pine since 1993, is now killing spruce trees as well.
"There were rumours before that pine beetles were not only killing spruce but successfully reproducing in spruce, and we have now observed that in Prince George and we have been trying to document what's going on," Staffan Lindgren, a professor of ecosystem science at UNBC, said yesterday.
Lodgepole pine is the most common timber in forest rich BC, covering 14 million hectares of land. Spruce is right behind and covers 13 million hectares. With that in mind, the threat posed by the mountain pine beetle is arguably the most visible and significant consequence of global warming yet seen on the North American continent.
In short, welcome to global warming induced evolution.
Historically, pine beetle populations are kept in check by winter temperatures that drop to -40°C for several days. But since 1993, warmer winters have meant that the beetle has been left untouched by prolonged cold periods and their numbers are skyrocketing accordingly. With greater numbers of beetles comes greater opportunity to take advantage of new evolutionary niches.
One might expect genetic variability within the pine beetle to allow rare individuals to thrive on spruce rather than pine, but they would have been few and far between and would be unlikely to form new breeding populations even if they survived the winter freeze. That changes when the natural weather cycle no longer keeps their numbers in check. What was once an insignificant genetic mutation now threatens our forests with the seeds of a whole new catastrophe.
From the disappearance of the bees that pollinate our crops, to the decimation of our forests, nature is issuing ever more severe warnings that the course our society is on is not in tune with our long term survival. It's time to stop pretending we're both deaf to the message and dumb towards action and begin changing the way we interact with the planet - for our own sake.