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Ecological Framework of Canada
Ecoregions of Canada


The ecoregion includes the lowlands centred on the Ottawa and St. Lawrence rivers stretching from Quebec City to the Frontenac Axis near Brockville, Ontario. It is bounded on the north by the hilly Laurentian Highlands and the Eastern Quebec Uplands to the south. The ecoregion is marked by warm summers and cold snowy winters. Moist summers are more prevalent west of Montreal. The mean annual temperature is approximately 5°C. The mean summer temperature is 16.5°C and the mean winter temperature is -7°C. The mean annual precipitation ranges 800-1000 mm. Mixedwood forests of sugar maple, yellow birch, eastern hemlock, and eastern white pine form the most stable vegetation in the region; beech occurs on warmer sites. Dry sites are dominated by red pine, eastern white cedar, and red oak. Wetter sites support red maple, black ash, white spruce, tamarack, and eastern white cedar. Underlain by flat-lying Palaeozoic strata that are either faulted or lie upon the crystalline rocks of the Canadian Shield, the ecoregion is rarely more than 152 m asl, except for the seven Monteregian Hills in the south, which are formed of intrusive igneous rocks. Gleysolic soils developed on level, poorly drained, clayey deposits are dominant in the region; significant inclusions are Humo-Ferric Podzols and Dystric Brunisols on morainal uplands. Characteristic wildlife includes deer, black bear, moose, wolf, hare, chipmunk, other small mammals, waterfowl, and other birds. Most of the region is intensively cultivated farmland (60%) with corn being the dominant crop grown. Dairy and mixed farming systems prevail. Urban development is extensive. The major communities include Quebec City, Montreal, Trois-Rivières, Saint-Hyacinthe, Cornwall, Brockville, Ottawa/Hull, and Pembroke. The population of the ecoregion is approximately 5 910 000.

This ecoregion is part of the Mixedwood Plains ecozone.