This ecoregion covers a significant east to west expanse. Much of it falls within the mainland boundaries of the Northwest Territories, although it also includes part of Quebec. Specifically, it stretches from the Dease Arm Plain in its northwestern reaches, through the plains and lowlands of the central Northwest Territories, to the Ottawa and Belcher Islands in Hudson Bay and the southern and western sections of Southampton Island, to the central Ungava peninsula in northern Quebec.
The great majority of this ecoregion is classified as having a low arctic ecoclimate. The only exceptions are the Dease Arm plain, stretching from Great Bear Lake to the east side of the Mackenzie River delta, and the Belcher Islands, in the southeastern part of Hudson Bay. The ecoregion experiences short, cool summers, with mean local temperatures ranging from 4°C to 6°C. Winters are long and very cold, with local mean temperatures from -28°C in the northwest to -17.5°C in the southeast. Mean annual precipitation varies widely across the ecoregion, from 200 millimeters (mm) in the northwest around the Amundsen Gulf coast, to 500 mm in northern Quebec. Particular local effects are evident in certain portions of the region, especially in the offshore island systems in the Coronation Gulf and Hudson Bay, where open water in the late summer and early fall moderates local climate and creates drizzly, foggy seasonal weather.
The physiography of this ecoregion varies considerably due to its size. The ecoregion is largely underlain by Precambrian granitic bedrock. The terrain consists mostly of broadly rolling uplands and lowlands. Throughout the ecoregion, there are exposures of bedrock. Strung out across the landscape are long, sinuous eskers reaching lengths of up to 100 kilometers (km) in places. A small part of the ecoregion west of the Firth River is unglaciated. The undulating landscape is studded with numerous lakes, ponds, and wetlands. Virtually the entire area is underlain by continuous permafrost with active layers that are usually moist or wet throughout the summer.
The ecoregion is characterized by a continuous cover of shrubby tundra vegetation. Permafrost is continuous with low to high ice content, except for discontinuous permafrost in the Ottawa Islands ecoregion and Belcher Island ecoregion. Vegetation in some areas can be described as tundra-subarctic forest transition, including black spruce (Picea mariana), tamarack (Larix laricina), white spruce (P. glauca), dwarf birch (Betula spp.), willow (Salix spp.), heath species. In addition, herb and lichen species are very common, in mixture with other vegetation. Some major river valleys support outlying spruce growth, and wetlands are very common in lowlands throughout the ecoregion. Much of the area represents an area of vegetative transition between the taiga forest to the south and the treeless arctic tundra to the north.
There is a great diversity of mammal species that inhabit this ecoregion. Notably, it is the major summer range and calving grounds of some of Canada’s largest caribou herds (Rangifer tarandus), barren-ground caribou in the west and woodland caribou in the east. Other mammals include grizzly bear (Ursus arctos), black bear (U. americanus) in northern Quebec, polar bears (Ursus maritimus) in coastal areas, wolf (Canis lupus), moose (Alces alces), Arctic ground squirrel (Spermophilus parryi), and brown lemming (Lemmus sibiricus). Many migratory birds depend upon the ecoregion as primary breeding and nesting grounds. Representative species include yellow-billed, red-throated and arctic loon (Gavia adamsii, G. stellata and G. arctica) tundra swan (Cygnus columbianus), snow goose (Chen caeruleswcens), oldsquaw (Clangula hyemalis), gyrfalcon (Falco rusticolus), willow and rock ptarmigan (Lagopus lagopus and L. mutus), red-necked phalarope (Phalaropus lobatus), parasitic jaeger (Stercorarius parasiticus), snowy owl (Nytctea scandiaca), hoary redpoll (Carduelis hornemanni), and snow bunting (Plectrophenax nivalis). In the marine environment, typical species include walrus (Odobenus rosmarus), seal (Phocidae), beluga whale (Delphinapterus leucas), and narwhal (Monodon monoceros).
Significant ecological phenomena within this ecoregion include several barren-ground caribou (Rangifer tarandus ssp. arcticus) herds totaling 1.5 million animals. Globally, the world’s total breeding populations of snow and Ross’ goose (Chen rossii) nesting colonies are found here. In addition, the largest mainland muskox (Ovibos moschatus) population and only ‘blonde muskoxen’ are found in this area.
Habitat Loss and Degradation
Approximately 95 percent of the natural habitat of this ecoregion is estimated to be intact. There is terrain disturbance in the vicinity of communities, abandoned military sites, and areas with mining exploration and active mines. Some habitats, such as raised beach ridges and areas of glacial outwash, are more threatened as these gravel deposits are sought after for road, air strip, and other construction needs.
Remaining Blocks of Intact Habitat
Most of the ecoregion is intact.
Degree of Fragmentation
Caribou seasonal range (behavioral, not habitat) fragmentation is conceivable for the Bathurst herd as a cumulative effect from mining exploration sites and mine construction.
Degree of Protection
- Thelon Wildlife Sanctuary - Northwest Territories - 52,925 km2
- Tuktut Nogait National Park - Northwest Territories - 22,145.82 km2
- Queen Maud Gulf Migratory Bird Sanctuary (MBS) - Northwest Territories - 62,782 km2
- Harry Gibbons MBS - Northwest Territories - 1,489 km2
- McConnell River MBS - Northwest Territories - 329 km2
Types and Severity of Threats
General threats to arctic regions apply, such as atmospheric fallout resulting in heavy metal and pesticide pollution. There is a risk of site-specific oil and chemical spills, and tailing effluent escapes. Mining is a rapidly growing industrial threat in parts of this ecoregion, especially with respect to diamonds and copper. Associated road building is in the planning stages and may be a significant threat for some species and habitats. Ecotourism will need to be carefully managed in order that nesting bird colonies, caribou calving grounds and other sensitive wildlife species are not disturbed. With increased access, over-hunting of caribou is a possibility and commercial harvesting of both caribou and muskoxen needs to be carefully monitored and controlled. In addition, carnivore deaths resulting from human defense and nuisance kills (especially for wolverine (Gulo gulo) and grizzly bears) may further impact predator-prey dynamics.
Suite of Priority Activities to Enhance Biodiversity Conservation
- Upgrade protection standards for Queen Maud Gulf MBS, Northwest Territory, specifically regulations pertaining to mining and mineral exploration.
- Protect two candidate sites (one provincial park and one ecological reserve) in Quebec.
- Protect caribou calving grounds by establishing land use regulations for caribou migration routes/corridors, especially post-calving aggregations.
- Establishing a buffer zone to connect the Beverly caribou calving grounds to the Thelon National Wildlife Sanctuary and the Queen Maud Gulf MBS.
- Introducing regulations to reduce the removal of gravel-laden landforms for road fill and airstrips. These are critical habitats for many arctic species during at least a part of their seasonal movements.
- Adjust wildlife management plans to accommodate losses (both individuals and important habitat) due to increasing human encroachment, especially with respect to mining and related activities.
- Canadian Arctic Resources Committee
- Canadian Nature Federation
- Ecology North
- Inuvialuit Game Council, Joint Secretariat
- Kativik Aboriginal Government
- Société Makivik
- World Wildlife Fund Canada, Quebec Region
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