Encircling the earth's Northern Hemisphere just south of the Arctic Circle, this green mantle of mainly coniferous forest comprises about 16.6 million square kilometres, or roughly one-third of the planet's forested area. Russia is the custodian of the largest portion of the boreal, containing just under 60 per cent of this woodland, while Canada's share is close to 30 per cent. The Scandinavian countries account for nearly 10 per cent, with the remainder existing in China, the United States (Alaska) and some other northern countries.

The Canadian portion of the boreal region stretches from the Yukon and northeastern British Columbia across the northern parts of the Prairie provinces, Quebec and Ontario to Labrador and Newfoundland. It forms a band more than 1000 kilometres wide. This area is primarily publicly owned and is rich in natural resources.

The Canadian boreal forest began to form after the retreat of the glaciers approximately 10,000 years ago. Natural disturbances such as fire and insects have played, and continue to play, a major role in the boreal forest's development and renewal. Human beings too have had a major influence on its development.