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The mid-continental Canadian forest ecoregion extends from southern Great Slave Lake in NWT to encompass most of northeastern Alberta, central Saskatchewan and parts of west-central Manitoba. This ecoregion is classified as having a subhumid mid-boreal ecoclimate. It is marked by short, cool-to-warm summers and long, cold winters. The mean annual temperature ranges from -2°C to 1°C; the mean summer temperature ranges from 13°C to 15.5°C; and the mean winter temperature ranges from -17.5°C to -13.5°C. Mean annual precipitation ranges from 300 mm to 625 mm, with the wettest areas being in the southeastern portions of the Mid-Boreal Lowland (ESWG 1995). This ecoregion consists of both lowland and upland areas which may be grouped into three regions: the Slave River Lowland in northeastern Alberta; the Mid-Boreal Lowland, which comprises the northern section of the Manitoba Plain; and the Mid-Boreal Uplands, which occur as a group of upland areas south of the Canadian Shield stretching from north-central Alberta to southwestern Manitoba. The lowland areas are underlain by relatively flat, low-relief Palaeozoic carbonates forming undulating sandy plains, or flat-lying Paleozoic limestone bedrock covered by level to ridged glacial till, lacustrine silts and clays, and extensive peat deposits. The upland areas, for the most part, consist of Cretaceous shales, and are covered entirely by kettled to dissected, deep, loamy to clayey-textured glacial till, lacustrine deposits, and inclusions of coarse, fluvoglacial deposits (ESWG 1995). Elevations in the uplands range from about 400 to over 800 m asl. Both upland and lowland areas have sporadic, discontinuous permafrost with low ice content, but the occurrence of permafrost is much rarer in the upland regions and is found only in peatlands. Wetlands and peatlands are prevalent in this ecoregion, especially in the lowland areas, while small lakes, ponds, and sloughs fill numerous shallow depressions associated with rougher morainal deposits in the upland regions (ESWG 1995).
The ecoregion forms part of the continuous mid-boreal mixed coniferous and deciduous forest extending from northwestern Ontario to the foothills of the Rocky Mountains. The mixed coniferous and deciduous forest is characterized by medium to tall closed stands of quaking aspen (Populus tremuloides) and balsam poplar (Populus balsamifera) with white and black spruce (Picea glauca and P. mariana), and balsam fir (Abies balsamea) occurring in late successional stages. Cold and poorly drained fens and bogs are covered with tamarack (Larix laricina) and black spruce, and may also include ericaceous shrubs (Ericaceae) and mosses. Deciduous stands in the uplands have a diverse understory of shrubs and herbs; while coniferous stands tend to promote feathermoss (ESWG 1995). Fire, drainage, and topography are probably the most significant factors influencing species assemblages. Characteristic wildlife species includes moose (Alces alces), black bear (Ursus americanus), wolf (Canis lupus), lynx (Lynx canadensis), white-tailed deer (Odocoileus virginianus), elk (Cervus elaphus), beaver (Castor canadensis), muskrat (Ondatra zibethica), snowshoe hare (Lepus americanus), ducks, geese, American pelican (Pelecanus erythrorhynchos), sandhill crane (Grus canadensis), ruffed grouse (Bonasa umbellus), common loon (Gavia immer) and many other bird species. The Interlake Plain to the south is home to moose, coyote (Canis latrans), and eastern cottontail (Sylvilagus floridanus) as well (ESWG 1995). Wood Buffalo National Park-within the Slave River Lowland-is populated by the world's largest bison (Bison bison) herd. The principal breeding range for whooping cranes (Grus americana) in North America is found within this ecoregion. The wetlands found here are of hemispheric significance to waterfowl migration, including many staging sites. The Cumberland delta-a very large wetland complex-is one such example. This 'inland' delta was formed in post-glacial times on a lake that no longer exists. This ecoregion also has a rich diversity of large ungulate species: bison (Bison bison), elk, woodland caribou (Rangifer tarandua ssp. caribou), moose and deer. In addition, the northern most bat hibernacula in North America are located within this ecoregion (Manitoba). Habitat Loss and Degradation It is estimated that 50 percent of the ecoregion remains as intact habitat. Most of the remaining habitat is considered as altered with only a very small percentage defined as heavily altered. Most habitat disturbance has resulted from large scale forestry operations, oil and gas development in western Saskatchewan, and localized areas of mining activity. Remaining Blocks of Intact Habitat
Degree of Fragmentation Habitat fragmentation is occurring primarily due to extensive forestry activity across the landscape. Large areas of boreal forest are under forest licences. Logging roads and clearcuts are significant in parts of the ecoregion. Degree of Protection
- 31,364.9 km2
Types and Severity of Threats Existing and proposed logging throughout the ecoregion are a serious threat. In some areas, the potential for increased oil and gas development is also a concern.
Establish protected areas in the following locations:
Alberta Wilderness Association Canadian Nature Federation Canadian Parks and Wilderness Society, Calgary/Banff Chapter Canadian Parks and Wilderness Society, Edmonton Chapter Ducks Unlimited Canada, Saskatchewan Ecosystem Endangered Spaces Campaign, Manitoba Endangered Spaces Campaign, Saskatchewan Federation of Alberta Naturalists Friends of Prince Albert National Park Manitoba Future Forest Alliance Manitoba Naturalists Society The Nature Conservancy, Alberta The Nature Conservancy, Manitoba Nature Saskatchewan Resource Conservation Manitoba TREE - Time to Respect the Earth's Watchdogs for Wildlife World Wildlife Fund Canada  Relationship to other classification schemes The Mid-Continental Canadian Forests are located in the Boreal Plains ecozone. The terrestrial ecoregions that correspond to this region are the Slave River Lowland, the Mid-Boreal Uplands, and the Mid-Boreal Lowland (TEC 136, 139-142, 144, 147, 148 and 150-154) (Ecological Stratification Working Group 1995). In Rowe's (1972) forest classification system, this area corresponds to the following Boreal forest sections: Manitoba Lowlands, Mixedwood, Hay River, Lower Foothills and Upper Mackenzie (18a and b, 19a and 23a). Prepared by: J. Shay, S. Smith, A. G. Appleby, R. Usher, G. Whelan Enns, K. Kavanagh, M. Sims, G. Mann. This text was originally published in the book Terrestrial ecoregions of North America: a conservation assessment from Island Press. This assessment offers an in-depth analysis of the biodiversity and conservation status of North America's ecoregions. All text by World Wildlife Fund © 2001 For more general information on this ecoregion, go to the WildWorld version of this description.
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