Tundra Disappearing At Rapid Rate

Forests of spruce trees and shrubs in parts of northern Canada are taking over what were once tundra landscapes–forcing out the species that lived there. This shift can happen at a much faster speed than scientists originally thought, according to a new University of Alberta study that adds to the growing body of evidence on the effects of climate change.

…These changes are of particular importance in these northern regions where First Nation people still rely heavily on the land, says Danby. Tundra species like caribou and sheep populations, which are important parts of that lifestyle, have declined across southwestern Yukon. As treeline advance, the reflectance of the land surface declines because coniferous trees absorb more sunlight than the tundra. This light energy is then re-emitted to the atmosphere as heat. This sets up a “positive feedback,” the same process that is associated with the rapidly decaying Arctic ice cap.

“These results are very relevant to the current debate surrounding climate change because they provide real evidence that vegetation change will be quite considerable in response to future warming, potentially transforming tundra landscapes into open spruce woodlands,” said Danby, who will also be participating in an International Polar Year project that will be examining treeline dynamics across the circumpolar north.

Science Daily