Survival of B.C.’s forests might depend on the industry that harvests them as global temperatures rise.
A process, loosely called “assisted migration,” is part of the federal and provincial governments’ overall response to climate change that includes genetic and selective breeding research carried out by the forest industry, government and Genome B.C., a non-profit research organization that manages large-scale research projects.
Selectively breeding trees for quality, volume and pest resistance has been ongoing since the late 1940s, but Vancouver Island-based forestry companies, such as TimberWest, now also plant trees tolerant to drought conditions to ensure future harvests.
“You don’t breed trees for their climate adaptability,” said Domenico Iannidinardo, TimberWest vice president of sustainability and chief forester. “You go to other ends of their ranges. They call it assisted migration. You go to Oregon, you take some Douglas fir trees from there and you start matching them with what you think is going to be good for our sites in the next 20 years.”
Thousands of years ago when the Earth was warmer, various species of redwoods covered much of North America, including coastal B.C.
Their fossilized remains are still found on the Lower Mainland.
As the climate cooled, redwood forests retreated south to California to be replaced by Douglas fir, western hemlock, western red cedar and other species now native to the Island.
Forest ecosystems migrate as global temperatures rise and fall and can suffer along the way.
According to the B.C. Ministry of Forests Lands and Natural Resource Operations, the mountain pine beetle infestation that peaked in 2007 damaged or killed 18 million hectares of trees – about one third of B.C.’s 55 million hectares of coniferous forest – equalling an area five times the size of Vancouver Island.
Pine beetle numbers exploded after several winters failed to produce extended extreme cold periods needed to kill off pine beetle larvae and keep numbers in check. The destruction was a wake-up call that natural forest migration isn’t keeping pace with the current rate of climatic change.
Without human intervention the consequences could be decades of stressed forests leading to pests infesting weakened trees and die-offs that leave large amounts of material on the forest floor, creating the potential for highly destructive forest fires.
Current research efforts – assuming global temperatures continue to rise – hope to prevent those negative spirals from occurring and maintain forest land productivity.
“With this we avoid the lag,” Iannidinardo said. “We avoid the forests that’ll be dying back for a few centuries before the new forest comes in. We’re going to fill that gap with our knowledge and our selected seeds.”