A forest region is defined as a major geographic belt or zone characterized by a broad uniformity both in physiography and in the composition of the dominant tree species. Canada can be divided into eight forest regions. Sometimes tundra and grasslands are included as forest regions nine and 10, but they are not real forests.

Boreal Forest Region

Approximately 80 per cent of Canada's forested land is in the immense boreal forest region, which swings in an arc south from the Mackenzie River Delta and Alaskan border to northeast British Columbia, across northern Alberta and Saskatchewan, through Manitoba, Ontario and Québec, terminating in northern Newfoundland on the shores of the Labrador Sea. The northern boreal region consists of open forest with trees growing farther apart and smaller in size as the forest stretches towards the tundra, where only dwarf specimens persist.

The southern boreal region presents a denser, closed forest which, at its southwest boundary in the Prairie provinces, gives way to a transitional zone dominated by poplar. Known as the aspen grove, this part of the forest thins out into open, almost treeless prairie. White and black spruce are the principal species of the predominantly coniferous boreal forest, but other conifers (e.g., balsam fir, jack pine and tamarack) also have a wide distribution. There is a general mixture of broad-leaved trees in the region, including white birch, balsam poplar and the wide-ranging trembling aspen.

Great Lakes-St Lawrence Forest Region

Although it is less than one-tenth the size of the boreal forest, the Great Lakes-St Lawrence is Canada's second-largest forest region. With the exception of a 322 km gap where the boreal region touches the north shore of Lake Superior, this forest stretches from southeastern Manitoba to the Gaspé Peninsula. It is bordered to the south by the deciduous forest region, and is a transitional forest between the coniferous and broad-leaved regions. Characteristic species are eastern white pine, red pine, eastern hemlock and yellow birch. Sugar and red maples, beech, red oak, basswood and white elm are also found, as are many boreal species.

Acadian Forest Region

Closely related to the Great Lakes-St Lawrence Forest Region, this region is confined to Nova Scotia, Prince Edward Island and a large portion of New Brunswick. Red spruce, balsam fir, yellow birch and sugar maple are commonly found. Black spruce, white and grey birch, red oak, white elm, black ash, beech, red maple, trembling aspen and balsam poplar are also widely distributed.

Deciduous Forest Region

Canada's smallest forest region, this area borders the southeast shore of Lake Huron and the northern shores of Lakes Erie and Ontario. Despite its small size, this region contains the largest number of native tree species of any region. Along with the broad-leaved trees common to the Great Lakes-St Lawrence Forest Region are found the cucumber tree, tulip tree, black gum, blue ash, sassafras, walnut and others which are at the northern limits of their range. Conifers occur only as a scattering of eastern white pine, tamarack, eastern red cedar and eastern hemlock.

Coast Forest Region

This region covers the lower seaward slopes of British Columbia's Coast Mountains and extends to the coastal islands. Characteristic species are western hemlock, Douglas fir, western red cedar and Sitka spruce, all renowned for their value as timber-producing trees. By comparison, the region's broad-leaved trees (e.g., black cottonwood, red alder, big-leaf maple) have a limited distribution and are of minor economic importance.

Subalpine Forest Region

Composed of coniferous forests, this region is situated on the mountain uplands of British Columbia and western Alberta. Characteristic trees are Engelmann spruce, alpine fir and lodgepole pine, while occasional species include western larch, whitebark pine and limber pine, together with yellow cypress and mountain hemlock on the more westerly ranges. The subalpine region makes an impressive contribution to the scenic splendour of the Canadian Cordillera and offers unique features of watershed protection and stream control in high-mountain source areas. The trees at lower elevations are harvested for timber.

Montane Forest Region

This region includes British Columbia's central plateau and several valley pockets adjacent to the Alberta boundary, areas which share a prevailing dry climate. The characteristic tree of this region is the blue Douglas fir, a smaller variety of the coast-region type. Lodgepole pine and trembling aspen are generally present and white spruce is found in cooler, shaded valley locations. In southern parts of the region's more open forest, ponderosa pine is common. Engelmann spruce and alpine fir from the subalpine region, together with western white birch, are important species of this region's northern limits.

Columbia Forest Region

This region lies in southeast British Columbia between the Rockies and the central plateau and fingers its way through the subalpine region along river valleys and lakes. The forest of this interior wet belt strongly resembles that of the coast region, although fewer species occur in the interior. Characteristic trees are western red cedar and western hemlock. The blue Douglas fir is widely distributed, and in southern parts western white pine, western larch, grand fir and western yew are found. Engelmann spruce is found in the upper Fraser Valley and occasionally at higher elevations in the region.

See also Vegetation Regions.