V i v i a n  S o n g
Freelance writer
Freelance writer
Moving targets a challenge

Toronto Sun, Sun Media papers, October, 2007.

Part 1 in a 5-day series

YELLOWKNIFE -- When Kevin Kennedy saw the unfamiliar four-legged animal saunter past his living room window, he went through a mental checklist of what it could have been.

"My mind went through all the possibilities," said the seven-year Yellowknife resident and city councillor.

The animal was a coyote, a normally south-dwelling animal that, up to a few years ago, was a stranger to these parts. But sightings of animals never seen in Yellowknife before have been on the rise, like white-tailed deer, cougars and magpies which are migrating further from their traditional habitats.

Experts warn that climate change could push Canada's tree line north by as much as 750 km in some areas, and bring with it new species while pushing old ones out.

"That will reduce the space for tundra and the wildlife it supports," points out Stewart Cohen, a senior researcher at Environment Canada. "Alpine trees may also be squeezed out if trees move to higher and higher elevations."

An increasing frequency of fires is expected to cut swaths through the fir, jack pine, and black and white spruce trees which dominate the boreal forest. Meanwhile, deciduous species like the leafy aspen, birch and poplar are projected to succeed their needly predecessors and change the face of the largely coniferous boreal forest in the next 50 years.

"As trees become more dense because a warmer climate allows them to grow taller, it will shift the ecosystem and plant species," explains Tom Lakusta, forest manager with the government of the Northwest Territories.

Subspecies of the black and white spruce, which grow in northern Alberta and Ontario, may also become better suited to the soils of their northern cousins, Lakusta says, and creep farther north.

According to Environment Canada, warmer temperatures will force sugar maple production in Quebec to shift northwards by two degrees of latitude over the next century. Already, sap flow has started up to one month earlier over the last decade and production seasons are shorter.

"One of the big challenges is we're trying to hit a moving target," says Sally Aitken, director of the Centre for Forest Gene Conservation at the University of British Columbia.

Eighty years from now warming temperatures will shift climatic conditions up to seven degrees in latitude, Aitken says. So trees in Prince George, B.C., for example, will weather summers and winters indigenous to places like Idaho with potentially harmful effects.

"The problem with climate change is that tree species are going to be in the wrong places ... there's going to be a big mismatch between the trees and their local environment," Aitken says.

That presents a conundrum for forest conservationists.

"We want to plant trees that will be healthy and grow well, but conditions are going to change throughout their lifetime," Aitken says. "If you move trees north early on, the seedlings will die from cold-related injury. But if you plant them where they're well adapted as seedlings now, in 60 years where it's four degrees warmer, mature trees may not be well-adapted. We don't know how to target that yet."

Website Builder