Ministry of Environment Ecology

PART II
Ecoregion Unit Descriptions

Polar Ecodomain

This Ecodomain covers the northern latitudes of North America, Asia, Europe and Greenland. In British Columbia, it occupies the northern plains, mountains, and plateaus. Its climate is characterized by generally low temperatures, a severe winter, and only small amounts of precipitation. In British Columbia it has been subdivided into 3 Ecodivisions.

Boreal Ecodivision

Boreal Plains Ecoprovince

This is one of three parts of the Polar Ecodomain in British Columbia. It occurs east of the Hart and Muskwa ranges, in their foothills and in the Alberta Plateau, on plateau, uplands, and in the Peace River Lowlands. There is typically a cold winter and a moderately warm summer. There is little precipitation. In the lowland areas, moist grassland mixed with trembling aspen develop. White and black spruce, and lodgepole pine dominate the uplands. In British Columbia this Ecodivision is represented by only one Ecoprovince.

Boreal Plains Ecoprovince

Location - This Ecoprovince lies east of the Rocky Mountains south of the Fort Nelson Lowlands. It occurs on the Alberta Plateau, and consist of plateaus, plains, prairies, and lowlands and is generally of low relief away from the deeply incised river beds. It extends eastward, across northern Alberta, Saskatchewan and Manitoba and southern Northwest Territory.

Climate - The climate is typically continental since most of the moist Pacific air has dried crossing successive ranges of mountains before it reaches the area. In warmer months rain is largely due to surface heating, which leads to convective showers. Winters are cold because there are no barriers to irruptions of Arctic air.

Biogeoclimatic Zonation - Vegetation is dominated by the Boreal White and Black Spruce Zone aspen parkland occurs in the Peace River Lowland and muskeg occurs throughout most of the upland surface. East of the Rocky Mountain Foothills, on low ridges, more mountainous vegetation develops, the Engelmann Spruce - Subalpine Fir Zone occurs on the summits of these ridges south of the Peace River, while the Spruce - Willow - Birch Zone occurs on those ridges north of the Halfway River.

Fauna - The most abundant large mammal is the moose. Both mule deer and white-tailed deer are common in the Peace Lowland Ecosection. Large carnivores include wolves and black bears. The only small mammal restricted to this region is the Arctic shrew.

This Ecoprovince supports 61% of all bird species known to occur in British Columbia and 46% of all species known to breed in the province - the fourth lowest total in British Columbia. The many wetlands, ponds, and slow-moving streams on the upland surface provide excellent habitat for breeding and migrating waterbirds. Some of the largest breeding concentrations of Eared Grebe occur in this Ecoprovince. Some of the rarest shorebirds in British Columbia regularly migrate through the Peace Lowland Ecosection. They include the Hudsonian Godwit, White-rumped Sandpiper, and Stilt Sandpiper. The area is the centre of abundance in the province for Broad-winged Hawk, Sharp-tailed Grouse, Upland Sandpiper, Franklin's Gull, common Grackle, and Eastern Phoebe. It is the only breeding area in the province for Philadelphia Vireo, Chestnut-sided Warbler, Black-throated Green Warbler, and Connecticut Warbler. The Boreal Plains Ecoprovince is also the major migratory corridor in British Columbia for Laplan.

The only reptile to occur in this Ecoprovince the common garter snake, is rare. Only one salamander, the long-toed salamander, and four species of toads and frogs occur here. One species, the northern chorus frog, has its centre of distribution in this Ecoprovince.

This Ecoprovince supports only freshwater fish such as, Arctic grayling, northern pike, walleye, slimy sculpin, flathead chub, lake trout, lake whitefish, northern squawfish and pearl dace.

Ecoprovince Subdivisions - In British Columbia the Boreal Plains Ecoprovince has three Ecoregions containing four Ecosections.

• The Central Alberta Uplands Ecoregion is a rolling plateau that rises slowly from the Peace River to the south. It contains two Ecosections in British Columbia.The Central Alberta Uplands Ecoregion is a rolling plateau that rises slowly from the Peace River to the south. It contains two Ecosections in British Columbia.

• The Clear Hills Ecosection is a smooth rolling upland that gradually rises in elevation towards the north and east. Numerous wetlands occur throughout.The Clear Hills Ecosection is a smooth rolling upland that gradually rises in elevation towards the north and east. Numerous wetlands occur throughout.
  The Halfway Plateau Ecosection is a rolling upland with some higher ridges it has wide valleys with some dissection by the small, southward flowing streams. Numerous wetlands and slow-moving streams occur on the upland surface.

 

• The Peace River Basin Ecoregion is a wide plain that lies between rolling uplands to the north and south; it is dissected by the Peace River and its tributaries. In British Columbia this Ecoregion is represented by only one Ecosection. The Peace River Basin Ecoregion is a wide plain that lies between rolling uplands to the north and south; it is dissected by the Peace River and its tributaries. In British Columbia this Ecoregion is represented by only one Ecosection.

• The Peace Lowland Ecosection is a large lowland that is deeply dissected by the Peace River and its tributaries. This Ecosection has the mildest climate with the lowest snowfall in this Ecoregion. The Peace Lowland Ecosection is a large lowland that is deeply dissected by the Peace River and its tributaries. This Ecosection has the mildest climate with the lowest snowfall in this Ecoregion.

 

• The Southern Alberta Upland Ecoregion is a rolling upland that rises from the Peace River Basin to the north and culminates in the Rocky Mountain Foothills to the south. In British Columbia this Ecoregion is represented by only one Ecosection. The Southern Alberta Upland Ecoregion is a rolling upland that rises from the Peace River Basin to the north and culminates in the Rocky Mountain Foothills to the south. In British Columbia this Ecoregion is represented by only one Ecosection.

• The Kiskatinaw Plateau Ecosection is a flat upland with some dissection by the Murray, Kiskatinaw and Wapiti rivers. Numerous wetlands occur on the upland surface. It is located in the southern portion of the Ecoregion adjacent to the Hart Foothills Ecosection.

Sub-Arctic Ecodivision

Taiga Plains Ecoprovince

This Ecodivision lies north of the Boreal Ecodivision and is the second part of the Polar Ecodomain in the province. It extends from the Fort Nelson River Basin to the border of the Northwest Territories. It is dry and cold. Winters are long and summers brief but plants gain some advantage from longer hours of daylight. There are some areas of permafrost. The riparian areas are dominated by balsam poplar. Better drained upland sites have white and black spruce, lodgepole pine (in British Columbia), and tamarack. Extensive wetlands and muskeg occur throughout the area because of poor drainage. In British Columbia this Ecodivision is represented by only one Ecoprovince.

Taiga Plains Ecoprovince

Location - This Ecoprovince lies to the east of the northern Rocky Mountains in the northeastern portion of British Columbia. It is characterized as a large lowland that has been dissected below the Alberta Plateau surface by the Liard River and its tributaries, namely the Fort Nelson and Petitot Rivers. It extends into the upper Mackenzie River Basin in the Northwest Territory.

Climate - The climate is continental. Cold, dense Arctic air is unimpeded from the north and may easily blanket the area in winter and spring. The long sub-Arctic winters are generally dark with little heating by solar radiation. In summer, its location between the Arctic and Pacific air masses give it long periods of cloud cover and unstable weather. In years of cold temperatures, or of more moisture, some soils may remain frozen.

Biogeoclimatic Zonation - Vegetation is dominated by the Boreal White and Black Spruce Zone. Black spruce bogs and wetlands are extensive.

Fauna - Moose are the most abundant ungulate, and black bear, and lynx are common carnivores. Scattered herds of caribou spend the winter months in all the upland, muskeg, and boreal forests. The muskrat, meadow vole, northern red-backed vole, and meadow jumping mouse are widely distributed small mammals.

This Ecoprovince supports the lowest diversity of birds of any terrestrial Ecoprovince in British Columbia with only 43% of all species known to occur in the province having been reported, the area holds only 35% of all species known to breed. Part of the reason for that low diversity may simply be a reflection of the very low level of observer effort in the region. It is the centre of abundance for breeding Lesser Yellowlegs and Solitary Sandpipers. Spruce Grouse are abundant in the extensive boreal forests. It is the only breeding area in the province for the Bay-breasted Warbler and is the centre of abundance for the Swamp Sparrow. Le Conte's Sparrow is locally abundant. Other breeding species of note include Cape May Warbler, Canada Warbler, Black and White Warbler, and Rose-breasted Grosbeak.

No reptiles are known to occur in this Ecoprovince and the only amphibians known to occur include the western toad, northern chorus frog, and wood frog.

This Ecoprovince supports only freshwater fish, such as, Arctic grayling, northern pike, walleye, inconnu, white sucker and lake whitefish.

Ecoprovince Subdivisions - In British Columbia, the Taiga Plains Ecoprovince has three Ecoregions and is divided into five Ecosections.

• The Hay River Lowland Ecoregion is a broad lowland area that lies below the higher portions of the Alberta Plateau to the north and south. There is only one Ecosection in British Columbia.

• The Fort Nelson Lowland Ecosection is physiographically part of the higher, Alberta Plateau to the south, however climatically it is part of the boreal climates of the lower, Northern Interior Plains.

 

• The Muskwa Plateau Ecoregion lies to the east of the northern Canadian Rocky Mountains. This Ecoregion is represented by only one Ecosection.

• The Muskwa Plateau Ecosection is a dissected upland area that rises above the Fort Nelson Lowland to the east.

 

• The Northern Alberta Upland Ecoregion is an area of extensive lowlands and low rolling plateaus that overlay flat-lying sedimentary bedrock. Muskeg predominates. In British Columbia it is represented by three Ecosections.

• The Etsho Plateau Ecosection is a rolling upland that rises above the Fort Nelson Lowland to the south.
• The Maxhamish Upland Ecosection is a rolling upland that lies below the Etsho Plateau to the east. On the west the Fort Nelson and Liard rivers have dissected the upland surface.
• The Petitot Plain Ecosection is a low lying area that has extensive wetlands and slow moving streams.

Sub-Arctic Highlands Ecodivision

Northern Boreal Mountains Ecoprovince

This Ecodivision is the third part of the Polar Ecodomain in British Columbia. It includes the mountains, high plateaus, and intermontane lowlands that extend from the northern part of the province into the Yukon, Northwest Territories, and Alaska. The area has severe and long winters with short summers. Precipitation does not vary greatly through the year but mountains in the east are generally drier than those in the west. Vegetation is characterized by muskeg and black spruce in low-lying areas with poor drainage. Low valleys often have willow-birch shrublands. White spruce and sub-alpine fir, and occasionally aspen, occur on the middle slope. Alpine grasslands dominate most rounded summits, while barren rock, and mat-vegetation occurs on the highest peaks. In British Columbia this Ecodivision is represented by only one Ecoprovince.

Northern Boreal Mountains Ecoprovince

Location - This Ecoprovince lies east of the Boundary Ranges of the Coast Mountains, west of the interior plains, and south of the Yukon Territory, in the north-central portion of British Columbia. The general character of this Ecoprovince is one of mountains and plateaus separated by wide valleys and lowlands. This area encompasses: the Teslin, Taku, Tanzilla, and Stikine plateaus, the Cassiar Mountains, the Liard Plain, Liard Ranges, the northern portion of the Alsek Ranges, the Skeena and Omineca Mountains, the northern Rocky Mountain Trench, the Muskwa Ranges, and associated foothills.

Climate - Prevailing westerly winds bring Pacific air to the area over the high St. Elias Mountains and Boundary Ranges. Coastal air is greatly reduced in moisture when it reaches the area, and this Ecoprovince is characterized by rainshadow effects that can cause some areas to be very dry. Summertime surface heating leads to convective showers which, together with winter frontal systems, result in precipitation amounts that are evenly distributed throughout the year. Outbreaks of Arctic air are frequent during the winter and spring. The rugged relief leads to a complex pattern of surface heating and cold air drainage in the valleys.

Biogeoclimatic Zonation - Vegetation is dominated by three zones: the Boreal White and Black Spruce Zone occurs throughout the valley bottoms and extensive plains, the Spruce - Willow - Birch Zone occurs throughout the high valleys and middle slopes of the mountains, while the Alpine Tundra Zone occurs throughout the middle to upper slopes of most mountains. Sporadic occurrence of two additional zones occurs adjacent to the large coastal valleys; the Sub-Boreal Spruce Zone occurs in the lower slopes of the lower Stikine and lower Taku River valleys, and the Englemann Spruce - Subalpine Fir Zone occurs on the middle slopes of those valleys.

Fauna - Moose are the most numerous and widely distributed ungulate, but the thinhorn sheep (both the pure white Dall's and Stone's) and caribou best characterize the fauna. Mountain goats are an abundant species in rugged alpine areas. Grizzly bears, black bears, and wolves are common throughout the valleys.

Characteristic small mammals include the collared pika, Arctic ground squirrel, tundra vole, and brown lemming. Wolverines and lynx are common.

This Ecoprovince supports only 52% of all bird species known to occur in the province and 42% of all species known to breed. However, many species breed nowhere else in British Columbia including the Pacific Loon, Gyrfalcon, Lesser Golden-Plover, Wandering Tattler, Hudsonian Godwit, Red-necked Phalarope, Arctic Tern, Northern Shrike, Smith's Longspur, Snow Bunting, and Common Redpoll. It is the centre of abundance for Willow and Rock ptarmigan, Bohemian Waxwing, and American Tree Sparrow, and it supports the only breeding population of the dark race (harlani) of the Red-tailed Hawk. It is the only breeding area other than the Okanagan Basin Ecosection for Brewer's Sparrow.

This Ecoprovince supports both anadromous and freshwater fish. The fish species vary because of the sea that the watersheds drain into. For example, the Stikine, Taku and Tatshenshini drain into the Pacific Ocean; the Yukon River drains into the Bering Sea; and the Liard and Peace rivers drain into the Arctic Ocean. Anadromous fish are restricted to the Stikine, Taku and Tatshenshini watersheds, and include, chinook and chum salmon. Freshwater fish include, Arctic grayling, Dolly Varden, lake trout, and lake whitefish; in the Liard and Peace river watersheds - northern pike and white sucker; in Teslin Lake and the Liard River - inconnu; in the Pacific watersheds -coastal cutthroat trout and Coast Range sculpin.

Ecoprovince Subdivisions - The Northern Boreal Mountains Ecoprovince is subdivided into seven Ecoregions containing sixteen Ecosections.

• The Hyland Highland Ecoregion is represented by only one Ecosection.

• The Hyland Highland Ecosection is an area of rolling upland that extends from northern British Columbia into the Yukon and Northwest Territories. This Ecosection provides a low barrier between the Interior Plains to the east and the valleys of the Canadian Cordillera to the west.

 

• The Liard Basin Ecoregion is an extensive area of lowland to rolling upland that extends from northern British Columbia into the Yukon and Northwest Territories. In British Columbia this Ecoregion is represented by only one Ecosection.

• The Liard Plain Ecosection is a broad, rolling inter-mountain plain with a cold, sub-Arctic climate.

 

• The Northern Canadian Rocky Mountains Ecoregion is an area of high, rugged mountains, several of which have large glaciers and rounded isolated foothills separated by wide valleys. This Ecoregion contains three Ecosections.

• The Eastern Muskwa Ranges Ecosection is the area with the highest, most rugged mountains in the Ecoprovince. It has more snowfall than the foothills to the east.
• The Muskwa Foothills Ecosection is an area of subdued mountains which are isolated by wide valleys. This area is in the rainshadow of the Rocky Mountains to the west; it is also more commonly under the influence of cold Arctic air in the winter.
• The Western Muskwa Ranges Ecosection is an area of deep, narrow valleys and rugged mountains. It has a cold, wet climate.

 

• The Boreal Mountains and Plateaus Ecoregion is a large area with a complex of lowlands, rolling and high plateaus and rugged mountains. It has a dry sub-arctic climate. In British Columbia this Ecoregion contains six Ecosections.

• The Cassiar Ranges Ecosection is the area with the highest and most rugged mountains in the Ecoregion. It has a broad band of mountains extending from the southeast corner of the Ecoregion to the northeast corner. The Cassiar Ranges Ecosection is the area with the highest and most rugged mountains in the Ecoregion. It has a broad band of mountains extending from the southeast corner of the Ecoregion to the northeast corner.
• The Kechika Mountains Ecosection is an area with high mountains, but low, wide valleys in the rainshadow of the Cassiar Ranges to the west.
• The Southern Boreal Plateau Ecosection consists of several deeply incised plateaus. Extensive rolling alpine and willow/birch habitat occurs. This Ecosection is located in the south-central part of the Ecoregion.
• The Stikine Plateau Ecosection is a plateau area with variable relief, from lowland to rolling alpine. Low elevations along the Stikine, Nahlin and Klastline river valleys are the driest in the Ecoregion.
• The Teslin Plateau Ecosection is a rolling plateau area, with several large lakes in the wide valleys. It lies in a distinct rainshadow.
• The Tuya Range Ecosection is the area with the most extensive rolling alpine landscape in the province.

 

• The St. Elias Mountains Ecoregion is a bold, ice-capped mountain area lying to the leeward of the Gulf of Alaska. In British Columbia it is represented by only one Ecosection.

• The Icefield Ranges Ecosection is mainly ice-capped, rugged mountain area that is the southern extension of the St. Elias Mountains.

 

• The Southern Yukon Lakes Ecoregion is a gently rolling upland, with isolated mountains separated by wide valleys. In British Columbia it is represented by only one Ecosection.

• The Teslin Basin Ecosection is a wide valley, with several large lakes, isolated mountains and rolling uplands occur along the margins.

 

• The Yukon-Stikine Highlands Ecoregion is a transitional mountain area lying between the rugged coastal mountains to the west and the subdued plateaus to the east. This Ecoregion contains three Ecosections.

• The Tagish Highland Ecosection is a transitional mountain area that faces northeast and all the streams drain into the upper Yukon River system. Barren alpine areas and snowfields are common.
• The Tahltan Highland Ecosection is a transitional mountain area with several large valleys exposed to the coast that allow moist air to dominate the lower slopes.
• The Tatshenshini Basin Ecosection is an area with rounded, subdued mountains and wide valleys leeward of the rugged Boundary and St. Elias Ranges. In spite of its close proximity to the Pacific Ocean, this area has a typically sub-arctic climate.

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