Run, Forest, Run

  • 2015-11-17
  • The Walrus

Sierra McLane stretched a rubber swim cap over her head, snapped her goggles into place, and swung her leg up and over the lowest branch of a gnarly whitebark pine tree. Her Ph.D. advisor, Sally Aitken, had sent the University of British Columbia student to Whistler to collect hundreds of pine cones in summer 2007, and the gear was her protection against sap. The whitebark is one of seven endangered tree species in Canada. More than 100 years ago, invasive fungi first started wiping out the conifers. Along with hungry mountain pine beetles, the fungi have pushed the tree to the brink. Global warming has provided its own pressures. A gloomy study by the United States Forest Service predicts that 97 percent of the pine’s native slopes will be too hot for the species past 2100, leaving little hope for the slow-growing tree, which can take up to eighty years to produce large crops of cones.

That hot August day, McLane was gathering cones for an audacious plan: to see if the trees could survive as far as 800 kilometres north of their current range. McLane and Aitken, the latter a forest geneticist at UBC, used climate models produced by their colleagues and scoured maps of BC’s projected future conditions to identify nine sites where the pines might thrive in a warming world. A few months later, after preparing the seeds to germinate from these cones in a lab, McLane and two assistants would drive the Toyota Tacoma pickup truck they nicknamed Bean more than 3,000 kilometres from Vancouver to the Alaskan border, dodging grizzly bears to plant 18,000 whitebarks on remote mountains—a testing ground for imagining forests of the future.

Other trees, including subalpine larches in western Canada and ashes in Ontario, are facing similarly dire outlooks. North America’s old-growth forests are dying at an alarming pace. Mortality rates are doubling approximately every two decades. While bugs, birds, and beasts race poleward to track their preferred climate zones, trees can’t move fast enough to outrun their enemies: longer drought seasons, hotter heat waves, freak cold spells, insects, and diseases. It’s not just our trees we stand to lose. Each year, Canadians harvest 150 million cubic metres of lumber—enough telephone poles to stretch from the earth to the moon nearly five times over. In 2013, forestry contributed $19.8 billion to the country’s economy. More than 321,000 Canadians work as loggers, millers, paper makers, planters, road builders, helicopter pilots, or truck drivers in the forests. One 2011 study, by the National Round Table on the Environment and the Economy, predicts that lost timber production from climate change could wipe between $25 billion and $176 billion from our collective bank accounts over the next seventy years.