<P> Canada's boreal region can be divided into eight ecozones . These eight can be divided into two main groups . The northern regions of the boreal forest consists of four eco-zones--Taiga Cordillera, Taiga Plains, Taiga Shield and Hudson Plains--that are the most thinly treed areas where the growing season and average tree size progressively shrinks until the edge of the Arctic tundra is reached . The southern tier of the boreal meanwhile consists of three other ecozones that form the largely uninterrupted or continuous forest in stretching as far south as Lake Superior in Ontario (as the Central Canadian Shield forests ecoregion) and the Manitoba - North Dakota border . These three southern zones are the Boreal Shield, at 1,630,000 square kilometres the largest of the eight zones, the Boreal Plains and Boreal Cordillera . A typical ecoregion of this southern tier would be the Eastern Canadian Shield taiga that covers northern Quebec and most of Labrador . Finally the eighth zone is the balsam fir Abies balsamea forest that covers the higher elevations of the Laurentian Mountains and the northern Appalachian Mountains in eastern Quebec (especially the Gaspé Peninsula), on the island of Newfoundland, in the highlands of New Brunswick, and the Cape Breton Highlands on Cape Breton Island, Nova Scotia . Within the boreal region, there are about 1,890,000 square kilometres that are between 80% to 100% forested and another 650,000 square kilometres with 60% to 80% forest cover . </P> <P> Most trees native to the Canadian boreal are conifers, with needle leaves and cones . These include: black spruce, white spruce, balsam fir, larch (tamarack), lodgepole pine, and jack pine . A few are broad - leaved species: trembling and large - toothed aspen, cottonwood and white birch, and balsam poplar . There are large areas of black spruce, a species which is tolerant of shallow soil, permafrost and waterlogged substrates, although as a consequence they have relatively low biological productivity . Owing to the short growing season, generally infertile soils, generally shallow soils, and frequent waterlogging, most of these forest types are slow - growing species, which generally tend to predominate in stressed habitats . Similarly, many of the understory shrubs are in the Ericaceae, a family known to tolerate acid, infertile and flooded habitats: examples include Labrador tea, sheep - laurel and blueberry . Since nutrient levels are so low, overall, the productivity of forest trees is highly dependent on the rate at which mineral elements such as nitrogen and phosphorus are recycled by litterfall and decomposition . After logging, the loss of nutrients may convert forested areas into shrub barrens dominated by shrubs such as sheep - laurel . Many of the plant species are fire - dependent, since fire removes neighbouring plants, and recycles nutrients locked in organic matter . </P> <P> Although there are rather few species of trees in the boreal forest, there is a considerable diversity of other kinds of plants . An accurate summary is difficult, since most compendia on plants are organized by political, rather than ecological boundaries; one exception addresses the flora of the Hudson Bay Lowland, but much of this area is not forested . One portion of the boreal forest can be used to illustrate plant diversity; consider the Flora of the Yukon . In this western part of the boreal forest, there are, for example 127 species of grass (Poaceae), 118 species of Asteraceae, 115 species of sedge (Cyperaceae), 93 species of crucifer (Brassicaceae), 52 species of Rosaceae, 37 species of Saxifragaceae and 36 members of the snapdragon family (Scrophulariaceae). Overall, the flora has 1112 species--there are even 15 species of orchids . </P> <P> Canada's boreal landscape contains more lakes and rivers than any comparably sized landmass on earth . It has been estimated that the boreal region contains over 1.5 million lakes with a minimum surface area of 40,000 square metres as well as some of Canada's largest lakes . Soft water lakes predominate in central and eastern Canada and hard water lakes predominate in Western Canada . Most large boreal lakes have cold water species of fish like trout and whitefish, while in warmer waters, species may include northern pike, walleye and smallmouth bass . </P>

Which area in canada contains one-quarter of earth's wetlands