This ecoregion in north-central British Columbia occurs as a relatively narrow band oriented in a northwest-southeast direction. It encompasses part of the Rocky Mountain trench and most of the Hart ranges of the Rocky Mountains and the Omineca Mountains (ESWG 1995).
This ecoregion’s climate is considered Alpine and Subalpine southern Cordilleran. Mean annual temperature is around 2°C, mean summer temperature is 12°C, and mean winter temperature is between - 10°C and -7°C. Mean annual precipitation ranges from 500-700 mm, increasing from the northwest toward the southeast, and with elevation from east to west in the south. Climatic conditions in the valleys are characterized by warm, dry summers and mild, snowy winters. Subalpine summers are cool, wet, and prone to early frosts. Subalpine winters are cold and snowy (ESWG 1995).
The western section of this ecoregion encompasses the southern section of the Omineca Mountains, which form a bed of Palaeozoic and Mesozoic sedimentary and massive crystalline rocks. The west also encompasses the eastern ranges of the Skeena Mountains, which are composed of Jurassic and Cretaceous sediments and volcanic strata. Both ranges have peaks around 2400 m asl. The central section of the Rocky Mountains run down the center of this region, and are relatively subdued, yet rise above the prairie plains to the east. The Eastern Continental ranges are linear with great cliffs and thick sections of gray carbonate strata. Rock outcrops are found along most peaks and ridges (ESWG 1995).
A vertically stratified complex of ecosystems characterize this ecoregion: low-elevation forests of interior western red cedar (Thuja plicata) and western hemlock (Tsuga heterophylla) in the northwestern, Skeena Mounatain, area; lodgepole pine (Pinus contorta), quaking aspen (Populus tremuloides) and white (Picea glauca) and black spruce (P. mariana) in the east; subalpine sections of Engelmann spruce (Picea engelmannii), alpine fir (Abies lasiocarpa), lodgepole pine and white spruce; and alpine tundra consisting of heather (Ericaceae), heath (Phyllodoce empetriformis), sedge (Carex spp.), and mountain avens (Dryas hookeriana) at the highest elevations.
Wildlife species include woodland caribou (Rangifer tarandus ssp. caribou), elk (Cervus elaphus), moose (Alces alces), black-tailed deer (Odocoileus hemionus), black bear and grizzly bear (Ursus americanus and U. arctos) (very high populations), beaver (Castor canadensis), wolf (Canis lupus), red fox (Vulpes vulpes), wolverine (Gulo luscus), marten (Martes americana), snowshoe hare (Lepus americanus), and ruffed grouse (Bonasa umbellus). Bighorn sheep (Ovis canadensis) and mountain goat (Oreamnos americanus) inhabit the rugged subalpine and alpine areas.
Among the rare ecological and evolutionary phenomena are large wetlands in valleys on the windward side of the Hart Ranges. The Rocky Mountain trench is a major north-south flyway for migratory birds. In addition, caribou (Rangifer tarandus) are found in southern parts of the ecoregion and Dall’s (Ovis dalli) and bighorn sheep are found within 150 kilometers of each other.
Habitat Loss and Degradation
Approximately 75 percent of this ecoregion remains as intact habitat. Logging has been one of the principle activities resulting in habitat loss and has to date been focused primarily in the Rocky Mountain Trench. It is now moving into all major valleys and along with increased road access, the rate of habitat loss is increasing significantly in some places. A major dammed reservoir (Williston Lake) now blocks east-west movement by wildlife across the Rocky Mountain Trench and to some degree the north-south movement down the Rocky Mountains. A major hydro-electric transmission corridor transects Pine Pass. Mineral exploration and mines are also responsible for habitat loss and degradation.
Remaining Blocks of Intact Habitat
•Omineca-Bear - approximately 5,000 km2 of Alpine/Subalpine
•Ospika - approximately 2,000 km2 of Alipne/Subalpine
•Mount Selwyn - approximately 1,500 km2 of Alpine/Subalpine
•Monkman Provincial Park - eastern British Columbia - 401.7 km2 of Alpine/Subalpine
NOTE: No valley bottoms, sub-boreal spruce forests, large (natural) lakes or river habitats remain that are unroaded, unlogged or without mineral exploration.
Degree of Fragmentation
Habitat fragmentation in this ecoregion has been caused primarily by road building and logging in valley bottom lands. Williston Lake (a reservoir) has created a major barrier to the movement of wildlife in the center of this ecoregion.
Degree of Protection
•Monkman Provincial Park - 401.7 km2
•Gwillim Lake Provincial Park - 91.99 km2
•Patsuk Creek Ecological Reserve - 5.54 km2
•Sukunka Falls Provincial Park - 3.6 km2
•Chunamon Creek Ecological Reserve - 3.44 km2
Types and Severity of Threats
Aside from the significant impacts of the Williston Reservoir on large mammals, logging is the most serious threat. All commercially viable forests are slated to be logged within the next 50 years.
Suite of Priority Activities to Enhance Biodiversity Conservation
•Establish more protected areas representative of the region, especially mid and low elevations and valley bottoms.
•Ensure that critical wildlife movement corridors are maintained.
•The Ecology Circle
•The Nature Conservancy, Alberta
•The Nature Conservancy,British Columbia
•Nechako Environmental Society
•Northwest Wildlife Preservation Society
•Prince George Naturalists
•World Wildlife Fund Canada
Relationship to other classification schemes
Within the Montane Cordillera Ecozone are the Central British Columbia Mountain Forests, which are distributed throughout the Omineca and Rocky Mountains (TEC 199 and 200) (ESWG 1995). As with other ecoregions in western Canada, the Northern BC forests are made up of different forest types. This ecoregion includes the Columbia forest region (1), Montane Transition (4), Interior Subalpine (2), and Tundra (Rowe 1972).
Prepared by: D. Demarchi, G. Smith, K. Kavanagh, M. Sims, G. Mann.