Central British Columbia Mountain forests
Omineca Mountains, central BC, Canada Photograph by Alain Plouffe/Used with permission of the Geological Survey of Canada, Natural Resources Canada
The Central British Columbia mountain forests ecoregion in north-central British Columbia, Canada 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. This ecoregion is within the Nearctic Realm.
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 to 700 millimetres, increasing from the northwest toward the southeast, and with elevation from east to west in the south. Climatic conditions in the valleys are characterised by warm, dry summers and mild, snowy winters. Subalpine summers are cool, wet, and prone to early frosts. Subalpine winters are cold and snowy.
The western section of this ecoregion encompasses the southern section of the Omineca Mountains, which form a bed of Paleozoic 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 metres above mean sea level. The central section of the Rocky Mountains extend down through the center of this ecoregion, 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.
Biological distinctiveness
A vertically stratified complex of ecosystems characterise 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.
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 150kilometres of each other.
Mammals
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.
Reptiles
There are several reptilian taxa that are found in the ecoregion: the Common garter snake (Thamnophis sirtalis) and the Western terrestrial garter snake (Thamnophis elegans).
Amphibians
Columbia spotted frog. Source: William Flaxington/ EoL The only salamander species found in the Central British Columbia mountain forests is the Long-toed salamander (Ambystoma macrodactylum); the only anuran species Western toad (Anaxyrus boreas), Columbia spotted frog Rana luteiventris) and Wood frog (Lithobates sylvaticus).
Conservation status
Habitat loss and degradation
Approximately 75 percent of this ecoregion remains as intact habitat. Deforest via logging has been one of the principal 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 locales. 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 hydroelectric 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 5000 square kilometers (km2) of Alpine/Subalpine
- Ospika - approximately 2000 km2 of Alpine/Subalpine
- Mount Selwyn - approximately 1500 km2 of Alpine/Subalpine
- Monkman Provincial Park - eastern British Columbia - 401.7 km2 of Alpine/Subalpine
Note that no valley bottoms, sub-boreal spruce forests, large (natural) lakes or river [[habitat]s] 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
Ecological 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
- Establish more protected areas representative of the region, especially mid and low elevations and valley bottoms.
- Ensure that critical wildlife movement corridors are maintained.
Conservation partners
- 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). As with other [[ecoregion]s] in western Canada, the Northern British Columbia forests are made up of different forest types. This ecoregion includes the Columbia forest region (1), Montane Transition (4), Interior Subalpine (2), and Tundra. The Central British Columbia mountain forests is given the ecocode NA0509 by the World Wildlife Fund.
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