Ministry of Environment Ecology

PART II
Ecoregion Unit Descriptions

Humid Temperate Ecodomain

This Ecodomain covers most of the mid-latitudes of North America from the east coast to the west. In British Columbia it occurs in the coastal islands and mountains, the central interior plateau, and the southern interior mountains. The climate is characterized by strong seasonal cycles of temperature and precipitation with a distinct winter. In British Columbia this Ecodomain is subdivided into two Ecodivisions.

Humid Maritime and Highlands Ecodivision

Coast & Mountains Ecoprovince
Georgia Depression Ecoprovince

This Ecodivision occurs along the coast from sea level to the height of land on the Coast Mountains. It includes the Nass Basin and Nass Ranges. Its climate is temperate and rainy with warm summers. precipitation is abundant through the year but is markedly reduced in summer. There is much cloud cover. The natural vegetation is usually a coniferous forest of Douglas-fir, western redcedar, western hemlock, Sitka spruce, amabilis fir, and yellow-cedar. It contains some of the world's largest trees and some of the densest coniferous forests. In drier parts of the extreme south of the province, it contains arbutus and Garry oak communities. In British Columbia this Ecodivision is subdivided into two Ecoprovinces.

Coast and Mountains Ecoprovince

Location - This Ecoprovince extends from coastal Alaska to coastal Oregon. In British Columbia it includes the windward side of the Coast Mountains and Vancouver Island, all of the Queen Charlotte Islands, and the Continental Shelf including Dixon Entrance, Hecate Strait, Queen Charlotte Strait and the Vancouver Island Shelf. The Coast and Mountains Ecoprovince consists of the large coastal mountains, a broad coastal trough and the associated lowlands, islands and continental shelf, as well as the insular mountains on Vancouver Island and the Queen Charlotte Islands archipelago.

Climate - The major climate processes involve the arrival of frontal systems from the Pacific Ocean and the subsequent lifting of those systems over the coastal mountains. In winter, oceanic low pressure systems dominate the area and pump moist, mild air onto the south and central coast. In summer, high pressure systems occur over the north Pacific Ocean and frontal systems become less frequent and tend to strike the coast further north.

Biogeoclimatic Zonation - Vegetation is dominated by the Coastal Western Hemlock and Mountain Hemlock Zones, Alpine Tundra Zone and glaciers occur on the mountain summits, Interior Cedar - Hemlock occurs in the Nass Basin, and transitional Interior Douglas-fir, Engelmann Spruce - Subalpine Fir, Boreal White and Black Spruce and Sub-Boreal Spruce occur along some of the eastern-most valleys. The subalpine zone is uncommon, and is composed of yellow-cedar and mountain hemlock, with blueberries and dense moss. Wet meadows are frequently found as part of the subalpine mosaic, with Indian hellebore, ragwort, hairgrass, and sedges. There is an unusually high frequency of endemic and rare species. The alpine vegetation zone is rare, with heaths formed by mountain-heathers.

Marine Zonation - There is a strong estuarine gradient across this Ecoprovince, from the freshwater discharges into fjords, across the protected continental shelf to the outer continental shelf. Fjord zones are very common, nearly all large rivers empty into fjords, rather than directly onto the continental shelf. A nearshore zone surrounds all the islets, islands and mainland, with a strong intertidal zone as the dominant interface between land and sea. Extreme wind and wave exposure occurs on the west coast of Vancouver Island and the Queen Charlotte Islands, whereas more protected coasts occur in the Dixon Entrance, Hecate Strait, Queen Charlotte Strait and inshore areas. Most of the continental slope is dominated by mesopelagic zonation with a surface, epipelagic layer.

Fauna - The mule deer ("black-tailed") is the only common large terrestrial ungulate to occur throughout this Ecoprovince. Mountain goats are widespread but restricted to rugged areas in the Coast Mountains. Black bears occur throughout this Ecoprovince, wolves are absent from the Queen Charlotte Islands, cougars are absent from the Boundary Ranges and Queen Charlotte Islands, while grizzly bears occur only on the mainland except in the south where they have been extirpated. The sea otter was once one of the most abundant shellfish predators, and the river otter is still numerous and very widespread. Northern sea lions and harbour seals occur along the coastal areas and the killer whale is a common inhabitant.

Characteristic small terrestrial mammals include the Keen's myotis, Vancouver Island marmot, and mink. There are many distinct island races of Townsend's vole and white-footed mouse.

The Coast and Mountains Ecoprovince holds the second highest number of birds in British Columbia, supporting 79% of all species known to occur in the province and 57% of those species known to breed. Waterbirds make extensive use of the coastal wetlands as well as nearshore and offshore habitats, including islands, islets, and cliffs. The colonial breeding seabirds are of note, and many of those species breed nowhere else in Canada. Offshore habitats provide feeding sites for pelagic birds like the Black-footed Albatross, Sooty Shearwater, jaegers, Northern Fulmar, gulls, and some shorebirds. Breeding Red-throated Loons and Spotted Owls are mostly restricted to this Ecoprovince. Some resident species, including the Bald Eagle, Peregrine Falcon, and Black Oystercatcher, contain significant portions of their world populations here. In winter, the estuaries and shores support most of the world's population of Trumpeter Swans and Barrow's Goldeneyes. The coast is also an important corridor for millions of migrating birds, especially shorebirds and waterfowl. The Towsend's Warbler is a high density breeder on Vancouver Island and the Queen Charlotte Islands. The Western Flycatcher is a high density breeder on the Queen Charlotte Islands.

The centre of abundance of the northwestern garter snake occurs here. The rough-skinned newt, northwestern salamander, western red-backed salamander, ensatina, clouded salamander, and red-legged frog are amphibians whose range is mostly restricted to the Coast and Mountains Ecoprovince.

This Ecoprovince supports a wide variety of fish, from purely oceanic species such as rockfish, sole, Pacific herring, Pacific halibut and spiny dogfish, to fish that spawn in freshwater, but live as adults in marine waters, such as the Pacific salmon, steelhead, coastal cutthroat trout and eulachon, through to the species that only live in fresh water, such as Coast Range and torrent sculpin.

In addition to fish the marine environment supports a wide variety of clams, barnacles, shrimp, crabs, starfish and jellyfish.

Ecoprovince Subdivisions - The Coast and Mountains Ecoprovince is divided into 11 Ecoregions containing 23 Ecosections.

• The Cascade Ranges Ecoregion is a large block of rugged mountains, that extend from southern Washington into southern British Columbia. It lies to the East of the Georgia Depression Ecoprovince. In British Columbia this Ecoregion contains only one Ecosection.

• The Northwestern Cascade Ranges Ecosection is a rugged block of mountains that extend southward into Washington, where they include several large, composite volcanoes.

 

• The Cascadia Continental Shelf Ecoregion is the shallow oceanic area which extends from Triangle Island and Cape Scope on Vancouver Island southward to California. It contains one Ecosection in British Columbia.

• The Vancouver Island Shelf Ecosection is a shallow oceanic area located west of Vancouver Island. It has a coast-hugging buoyancy current due to freshwater influence. There is seasonal upwelling along the western boundary with Continental Slope Ecoregion.

 

• The Coastal Gap Ecoregion contains somewhat rounded mountains with lower relief than mountain ranges to either the north or south. Valley sides are rugged and steep. Because of their lower relief, they allow considerable moisture to enter the interior of the province. The Ecoregion contains two Ecosections.

• The Hecate Lowland Ecosection is an area of low relief, consisting of islands, channels, rocks and lowlands adjacent to Hecate Strait and Queen Charlotte Sound.
• The Kitimat Ranges Ecosection is an area of subdued, yet steep-sided mountains, east of the Hecate Lowlands Ecosection.

 

• The Hecate Continental Shelf Ecoregion is the shallow oceanic area offshore of the Hecate Lowlands, south of the Alaska Panhandle and north of Vancouver Island. Much of this shelf lies leeward of the Queen Charlotte Islands. It contains four Ecosections.

• The Dixon Entrance Ecosection is located between northern Graham Island and Prince of Wales and Dall Islands in southeastern Alaska. This Ecosection has a strong freshwater discharge influence from the Skeena, Nass and other rivers.
• The Hecate Strait Ecosection is a broad semi-enclosed estuarine waterway located between the mainland coast, the Queen Charlotte Islands and northern Vancouver Island. This is a very shallow strait dominated by coarse bottom sediments. It has semi-protected waters with strong tidal currents that promote "mixing".
• The Queen Charlotte Sound Ecosection is a deeply dissected shelf area with several large intervening banks. This Ecosection is exposed to oceanic waves allowing for oceanic water intrusions.
• The Queen Charlotte Strait Ecosection is shallow marine area that is interspersed with many islands and reefs, located between northern Vancouver Island and the Hecate Lowland. There are strong currents mixing the oceanic and freshwaters.

 

• The Nass Basin Ecoregion is represented by only one Ecosection.

• The Nass Ranges Ecosection is a mountainous area west of the Kitimat Ranges. Its climate is somewhat transitional between coastal and interior regimes.

 

• The Northern Coastal Mountains Ecoregion is a rugged, largely ice-capped mountain range that rises abruptly from the coast. It contains three Ecosections in British Columbia.

• The Alaska Panhandle Mountains Ecosection is an area of wet rugged mountains. It is the southern, windward mountain segment of the three major units in this Ecoregion. Most of this Ecosection occurs in Alaska. In British Columbia this unit occurs in the areas of Portland and Observation inlets the lower Nass River.
• The Alsek Ranges Ecosection is an area of isolated, very rugged ice-capped mountains that lie in the curve of the Gulf of Alaska and are readily affected by moist, Pacific air. The valleys and lower slopes lie primarily to the south in Alaska. This is the smallest and most northerly of the Ecosections in this Ecoregion.
• The Boundary Ranges Ecosection is a large block of rugged, ice-capped, granitic mountains that are dissected by several major river valleys. It is the eastern or interior-most segment of the three major units in this Ecoregion. Most of this unit occurs in British Columbia.

 

• The Pacific Ranges Ecoregion is the southern-most mountain range of the Coast Mountains in British Columbia. It includes the coastal islands, channels and fjords east of Queen Charlotte Sound, otherwise it lies east of the Georgia Depression Ecoprovince. The mountains are characteristically high and rugged. It contains four Ecosections.

• The Eastern Pacific Ranges Ecosection is a rugged inland area that has transitional climates including some rainshadow. It lies west of the Southern Interior Ecoprovince.
• The Northern Pacific Ranges Ecosection is an area of steep, rugged, often ice-capped, mountains located in the northern portion of this Ecoregion.
• The Outer Fiordland Ecosection is an area of rugged, low relief, consisting of inlets, sounds, islands and peninsulas, east of Johnstone Strait and Seymour Narrows.
• The Southern Pacific Ranges Ecosection is an area of high rainfall on steep, rugged mountains located east of the Georgia Depression Ecoprovince and north of the lower Fraser River.

 

• The Queen Charlotte Lowland Ecoregion is represented by only one Ecosection.

• The Queen Charlotte Lowland Ecosection is an area of low relief, poor drainage and extensive muskegs and wetlands in the northeastern part of the Queen Charlotte Islands.

 

• The Queen Charlotte Ranges Ecoregion includes the fjords and mountains of the Queen Charlotte Mountains. Precipitation is somewhat reduced here. This Ecoregion is represented by two Ecosections.

• The Skidegate Plateau Ecosection is a plateau in the lee of the Queen Charlotte Mountains. Precipitation is somewhat reduced here.
• The Windward Queen Charlotte Mountains Ecosection is the very wet, rugged western side of the Queen Charlotte archipelago.

 

• The Western Vancouver Island Ecoregion includes the western lowlands, islands and mountains of Vancouver Island. It contains three Ecosections.

• The Nahwitti Lowland Ecosection is an area of low to rolling topography, with high precipitation located at the north end of Vancouver Island.
• The Northern Island Mountains Ecosection is a partial rainshadow of wide valleys and mountains located in the northern portion of Vancouver Island.
• The Windward Island Mountains Ecosection is the area of lowlands, islands, and mountains on the western margin of Vancouver Island.

 

Georgian Depression Ecoprovince

Location - This Ecoprovince lies between the Vancouver Island Mountains and the southern Coast Mountains. It is a large basin containing the Strait of Georgia and Puget Sound. In British Columbia, this Ecoprovince is a large basin that encompasses the southeastern Vancouver Island Mountains and the Nanaimo Lowlands in the west, the Strait of Georgia and Gulf Islands in the middle, and the Georgia Lowlands and the Fraser Lowlands in the east.

Climate - After moving over the Vancouver Island Mountains, surface air flow is level or subsiding and creates clearer and drier conditions than in coastal areas adjacent to the Pacific Ocean. The southern parts of this Ecoprovince have the greatest annual amounts of sunshine in British Columbia. Temperatures throughout the area are modified by the ocean and the Strait of Georgia.

Biogeoclimatic Zonation - Vegetation is dominated by the Western Hemlock Zone, Coastal Douglas-fir occurs along the Nanaimo Lowlands and Gulf Islands (its only occurrence in British Columbia), and Mountain Hemlock and Alpine Tundra Zones on the higher portion of the Vancouver Island Ranges.

Marine Zonation - This Ecoprovince is predominantly a semi-enclosed estuarine environment, strongly affected by freshwater discharge, especially from the Fraser River. A nearshore zone surrounds all the islets, islands, and mainland, with an intertidal zone as the dominant interface between land and sea. This Ecoprovince has only protected waters, but the Strait of Georgia is deep enough to have a mesopelagic zone as well as a epipelagic layer.

Fauna - Mule deer ("black-tailed") are very abundant in the rural and natural areas throughout the Ecoprovince. Other large mammals include cougar, "Roosevelt" elk (Vancouver Island), and coyote (Lower Mainland.) The extensive marine/land interface provides haul-out areas for harbour seals and northern and California sea lions. Off-shore, killer whales and harbour porpoises are common marine mammals. On-shore, in the estuaries, along river banks and lake shores, river otters, mink and raccoons are common predators.

Small mammals almost restricted to the Ecoprovince, include the Virginia opossum, marsh shrew, Trowbridge's shrew, shrew-mole, Townsend's and coast mole, Douglas' squirrel, eastern cottontail (introduced), and creeping vole.

This Ecoprovince supports the highest diversity of birds in British Columbia - 90% of all species known to occur in the province. It also has 60% of the species that are known to breed in British Columbia. Many of these species are casual and accidental - spotted by the many birdwatchers in the area.This Ecoprovince supports the highest diversity of birds in British Columbia - 90% of all species known to occur in the province. It also has 60% of the species that are known to breed in British Columbia. Many of these species are casual and accidental - spotted by the many birdwatchers in the area.

The wetlands of the Fraser River delta make up the largest single unit of wetland habitat in British Columbia. In addition, the mild climate enables it to be the most important migratory and wintering area for waterbirds in the province. Waterfowl are abundant, including Snow Geese during the winter months. The delta supports the largest wintering population of raptors in Canada. Notable among these are the Northern Harrier, Red-tailed Hawk, and Short-eared Owl. The delta is also important to migrating shorebirds, most of the world's Western Sandpipers stage, rest and feed there. In winter, Dunlin is the most numerous shorebird.

Large numbers of waterbirds winter in bays, surge narrows, and estuaries throughout the Georgia Depression Ecoprovince. Notable among these are the Pacific Loon, Western Grebe, Brandt's Cormorant, Common and Barrow's goldeneyes, Surf, White-winged and Black scoter, Greater and Lesser scaup, Thayer's and Glaucous-winged gulls, common Murre, and Marbled and Ancient murrelets. The area is also important to wintering shorebirds such as Black Turnstone and Surfbird.

The only resident populations of Barn Owl and Anna's Hummingbird occur in this Ecoprovince. The Gulf Islands support the only breeding colonies of Double-crested Cormorants and most of the colonies of Glaucous-winged Gulls in the province. Three species of passerines breed only in the Georgia Depression Ecoprovince: Purple Martin, Bushtit, and Hutton's Vireo. The Eurasian Skylark introduced to the Victoria area, and the Crested Myna, introduced to the Vancouver area, maintain the only North American breeding populations in this Ecoprovince.

Reptiles include the western pond turtle (introduced) and sharptail snake. Characteristic amphibians include the Pacific giant salamander, ensatina, bullfrog (introduced), and green frog (introduced).

This Ecoprovince supports a wide variety of fish from the purely marine species such as rockfish, flounder, spiny dogfish, Pacific herring and ling cod, to fish that spawn in freshwater, but live as adults in marine water, such as the Pacific salmon, steelhead, coastal cutthroat trout, and eulachon, through to the species that only live in fresh water, such as the introduced pumpkinseed and smallmouth bass, or the native peamouth chum and threespine stickleback. A few species move regularly from freshwater to the brackish estuaries and even marine environment, such as the green sturgeon, Dolly Varden, and Coast Range sculpin.

Ecoprovince Subdivisions - The Georgia Depression Ecoprovince in British Columbia is subdivided into three Ecoregions containing seven Ecosections.

• The Eastern Vancouver Island Ecoregion is an area of reduced rainfall leeward of the Vancouver Island Ranges. It is comprised of two Ecosections that correspond to physiographic differences. The Eastern Vancouver Island Ecoregion is an area of reduced rainfall leeward of the Vancouver Island Ranges. It is comprised of two Ecosections that correspond to physiographic differences.

• The Leeward Island Mountains Ecosection is a mountainous area from the crest of the Vancouver Island Ranges to the Nanaimo Lowlands.
• The Leeward Island Mountains Ecosection is a mountainous area from the crest of the Vancouver Island Ranges to the Nanaimo Lowlands.
  The Nanaimo Lowland Ecosection is a coastal plain that is situated on the southeastern margin of Vancouver Island. It has a mild climate with low snow depths.

 

• The Lower Mainland Ecoregion is an area of reduced rainfall, but precipitation increases towards the Coast Ranges and the rainshadow is most distinct on the lowlands and Fraser River delta. There are two Ecosections that correspond to physiographic differences.

• The Fraser Lowland Ecosection consists of the Fraser delta, estuary, lowlands, and associated uplands.
• The Georgia Lowland Ecosection consists of areas of low relief at the base of the Coast Ranges. Patches of rocky outcrop are connected by deposits of glacial gravel and debris. The Georgia Lowland Ecosection consists of areas of low relief at the base of the Coast Ranges. Patches of rocky outcrop are connected by deposits of glacial gravel and debris.

 

• The Georgia-Puget Basin Ecoregion is a semi-enclosed estuarine basin that includes several straits, troughs and island clusters. It extends from Johnstone Strait, south across the Canada/U.S.A. boundary to Nisqually Reach. In British Columbia this Ecoregion is subdivided into three Ecosections.

• The Southern Gulf Islands Ecosection is a collection of islands and inter-island channels and sounds that extends across the Strait of Georgia. The Southern Gulf Islands Ecosection is a collection of islands and inter-island channels and sounds that extends across the Strait of Georgia.
• The Strait of Georgia Ecosection is a broad shallow marine basin that separates southern Vancouver Island from the mainland. It holds several islands that have very dry mild climates.
• The Juan de Fuca Strait Ecosection is a deep trough marine area with a strong "estuary-like" outflow current. It is the major water exchange conduit between the Georgia - Puget Basin Ecoregion and the Pacific Ocean.

Humid Continental Highlands Ecodivision

Central Interior Ecoprovince
Sub-Boreal Interior Ecoprovince
Southern Interior Mountains Ecoprovince

This is the second part of the Humid Temperate Ecodomain in British Columbia. It occurs in the southeastern mountains and central plateau but does not cover the southern plateau area. It has a cold snowy winter with a warm summer. Precipitation is ample all year. The natural vegetation is a coniferous forest arranged in striking belts. At the lower levels there is a montane belt of Douglas-fir, and in the south, western larch. Grasslands are exceptional. The subalpine belt is usually dominated by Engelmann spruce and subalpine fir but western hemlock and western redcedar occur where moisture is increased. The uppermost belt is alpine where trees are absent. In British Columbia this Ecodivision has been subdivided into 3 Ecoprovinces.

Central Interior Ecoprovince

Location - This Ecoprovince lies to the east of the Coast Mountains between the Fraser Basin and the Thompson Plateau. The Central Interior Ecoprovince contains the flat to rolling Chilcotin and the Cariboo Plateaus and the southern two-thirds of the Nechako Plateau. It also contains the Chilcotin Ranges west to the centre of the Pacific Ranges and the Bulkley and Thatsa Ranges.

Climate - Some of the mountain ranges on the east side of the coastal mountains are included because they are much drier than the windward side and therefore have a more interior type of climate. The area has a typical continental climate: cold winters warm summers, and a precipitation maximum in late spring or early summer. However, the moderating influences of Pacific air occur throughout the year, as is the case for most of the province south of 57 N. The area lies in a rain shadow leeward of the coast mountains. In summer there is intense surface heating and convective showers, and in the winter there are frequent outbreaks of Arctic air (these are less frequent than in the area to the north).

Biogeoclimatic Zonation - Vegetation is dominated by the Interior Douglas-fir Zone in the south the Sub-Boreal Pine - Spruce Zone in the centre and the Sub-Boreal Spruce Zone in the north. In addition, the Bunchgrass Zone occurs within the deeply entrenched portion of the Fraser River, the Montane Spruce Zone occurs at middle elevations in the Chilcotin Ranges and southern Chilcotin Plateau, the Engelmann Spruce - Subalpine Fir Zone occurs on the middle slope of all mountains and the higher portion of the northern Chilcotin and southern Nechako Plateaus, the Alpine Tundra Zone occurs on the upper slopes of all mountains.

Fauna - Moose are the most widespread wild ungulate while mule deer occur in large populations in the southern plateau and Fraser River 'badlands' area. Several large populations of "California" bighorn sheep occur in the Fraser River badlands and alpine areas. Cougars, black bears, coyotes, and wolves are also common through the Ecoprovince. Widespread small mammals include the western jumping mouse, muskrat and long-tailed weasel. Two species of bat, big brown bat and Townsend's big-eared bat, hibernate in the Ecoprovince.

This Ecoprovince supports 65% of all bird species known to occur in British Columbia and 61% of all species known to breed in the province. The only breeding colony of the American White Pelican in the province is found in the Chilcotin Plateau. Excellent habitat for waterfowl and other waterbird (e.g. grebes) production exists throughout the plateau. The world centre of breeding abundance for Barrow's Goldeneye occurs here. It is also the centre of breeding abundance for Greater Yellowlegs and the Yellow-headed Blackbird and is one of two important breeding areas for Long-billed Curlew and Ring-billed Gull. High breeding concentrations are Eared Grebe, Sandhill Crane, Herring Gull, and Black Tern have also been found here.

The western terrestrial garter snake is the most common reptile while the western toad and spotted frog occur throughout the area.

This Ecoprovince supports both anadromous and freshwater fish. Anadromous species include: chinook salmon, sockeye salmon, steelhead, white sturgeon and Pacific lamprey. Freshwater fish include: rainbow trout (both native and introduced populations), Dolly Varden, mountain and lake whitefish, lake chub and redside shiner.

Ecoprovince Subdivisions - The Central Interior Ecoprovince contains three Ecoregions and twelve Ecosections.

• The Bulkley Ranges Ecoregion is represented by only one Ecosection.

• The Bulkley Ranges Ecosection is a narrow mountain area located leeward of the rounded Kitimat Ranges. Moist Pacific air invades this area through numerous low mountain passes, while cold Arctic air frequently stalls along its eastern boundary.

 

• The Chilcotin Ranges Ecoregion is an area of high, somewhat rounded mountains, located in the rainshadow of the Pacific Ranges. Precipitation is greatest in the Northwest portion and least in the southeastern portion. There are two Ecosection subdivisions.

• The Central Chilcotin Ranges Ecosection is a dry, rounded mountain area located leeward of the Pacific Ranges in the Southeast.
• The Western Chilcotin Ranges Ecosection is a rugged, moist mountainous area located just south of the low Kitimat Ranges.

 

• The Fraser River Plateau Ecoregion is a broad, rolling plateau that includes several shield volcanoes and a small portion of the leeward side of the Kitimat Ranges. The climate is somewhat continental, although sufficient moisture reaches the area by way of the low Kitimat Ranges. It contains nine Ecosections.

• The Bulkley Basin Ecosection is a broad lowland area, with a rainshadow climate. There are several large lakes in the valleys, some of which are artificial.
• The Cariboo Basin Ecosection is a rolling upland with dry forests, interspersed with wetlands and grasslands on southfacing slopes.
• The Cariboo Plateau Ecosection is an upland area with increased moisture and moderate temperatures in the southeast. The Cariboo Plateau Ecosection is an upland area with increased moisture and moderate temperatures in the southeast.
• The Chilcotin Plateau Ecosection is a flat upland area, with a rainshadow climate located in the central west area.
• The Fraser River Basin Ecosection is the dissected portion of the Chilcotin and Cariboo plateaus and the Fraser 'badlands' that lies between them. It has the warmest and driest climate in the Ecoregion.
• The Nazko Upland Ecosection is a flat upland area, with increased precipitation located in the north-northeast.
• The Nechako Upland Ecosection is a rolling upland area that has several high shield volcanoes with well developed alpine areas, the valleys usually contain large lakes, several of which are artificial. This Ecosection is located in the north-northwest adjacent to the Kitimat Ranges.
• The Quesnel Lowland Ecosection is a lowland area in the northeastern portion.
• The Western Chilcotin Upland Ecosection is an area with several high, rounded shield volcanoes, separated by wide valleys, on the western portion of the Ecoregion.

Sub-Boreal Interior Ecoprovince

Location - This Ecoprovince lies to the east of the Coast Mountains and to the west of the Interior Plains, in the north-central part of British Columbia. It consists of several physiographic systems: the low-lying plateau area of the Nechako Lowlands, the northern portion of the Nechako Plateau, and the southern portion of the Northern Rocky Mountain Trench. The mountains to the north and west include the southern Skeena and Omineca mountains, while those to the east include the Hart Ranges and associated foothills, the southern Muskwa Ranges and associated foothills, and the McGregor Plateau.

Climate - Prevailing westerly winds bring Pacific air to the area over the Coast Mountains by way of the low Kitimat Ranges or the higher Boundary Ranges. Much of this area is in a rain shadow. Coastal air has low moisture content when it arrives. Moisture does enter the area when there is a southwest flow over the low Kitimat Ranges. Summer surface heating leads to convective showers, and winter frontal systems result in precipitation that is evenly distributed throughout the year. Outbreaks of Arctic air are frequent. The southern edge of the Ecoprovince is near the typical southern extent of the Arctic air mass in January.

Biogeoclimatic Zonation - Vegetation is dominated by the Sub-Boreal Spruce Zone on the Nechako Plateau, Nechako Lowlands, Northern Rocky Mountain Trench, and many of the valleys; the Engelmann Spruce - Subalpine Fir Zone occurs on the middle slopes of all mountains and the Alpine Tundra Zone occurs on the upper slopes of those mountains; the Interior Cedar - Hemlock zone occurs in the wetter valleys of the Skeena Mountains, the Spruce - Willow - Birch zone occurs in the northern valleys of the Skeena Mountains, and the Boreal White and Black spruce Zone in the valley of the foothills and northern Omineca Mountains.

Fauna - In this Ecoprovince moose are the most abundant and widely distributed ungulate, while the black bear and wolf are common throughout and grizzly bear is abundant in the wet forests of the mountains. Lynx, fisher and muskrat are widely distributed throughout this region.

This Ecoprovince supports 57% of all bird species known to occur in British Columbia and 46% of all species known to breed in the province. The Boreal Owl is a typical resident species. Highest breeding numbers of Herring Gull and Black Tern occur here. Two passerine species of note are the Rusty Blackbird and Magnolia Warbler.

The only reptile is the rare common garter snake. Western toad, wood frog, and spotted frog occur throughout the Ecoprovince.

This Ecoprovince supports both anadromous and freshwater fish. Anadromous fish include: chinook and sockeye salmon. Freshwater fish include, rainbow trout (both native and introduced populations), lake trout, Dolly Varden, lake and mountain whitefish, Arctic grayling (in the Peace River watershed), longnose sucker, slimy sculpin and torrent sculpin.

Ecoprovince Subdivisions - The Sub-Boreal Interior Ecoprovince is divided into four Ecoregions containing 13 Ecosections.

• The Central Canadian Rocky Mountains Ecoregion consists of steep-sided",but round-topped mountains and foothills that are lower than ranges of the Rockies to either the south or the north. It contains four Ecosections.

• The Hart Foothills Ecosection is an area of low, rounded mountains and wide valleys on the east side of the Rocky Mountains. This is the driest Ecosection in this Ecoregion Cold Arctic air often stalls along the eastern margin or in the valleys.
• The Hart Ranges Ecosection is a mountainous area that forms a low barrier to the eastward moving Pacific air or southwestward moving Arctic air. The mountains build in height from north to south.
• The Misinchinka Ranges Ecosection is a rugged mountain area, with deep narrow valleys. Moist Pacific air often stalls over these mountains, bringing high precipitation, both summer and winter.
• The Peace Foothills Ecosection is a blocky mountain area on the east side of the Rocky Mountains. Strong rainshadows exist.

 

• The Fraser Basin Ecoregion consists of broad, flat lowlands and rolling uplands, located in the central plateau area of the interior of British Columbia. It has been subdivided into 3 Ecosections.

• The Babine Upland Ecosection is a rolling upland with low ridges and several large lakes in the depressions.
• The McGregor Plateau Ecosection is rolling upland adjacent to the Hart Ranges. A cool moist climate occurs here.
• The Nechako Lowland Ecosection is a broad, flat lowland with some dissection by the Fraser and Nechako rivers. Although the climate is sub-boreal, this Ecosection has a milder climate than any other in this Ecoprovince.

 

• The Omineca Mountains Ecoregion consists of several mountain groups that are dominantly rounded, isolated ranges that are more prominent in the north than in the south. This Ecoregion is divided into four Ecosections.

• The Eastern Skeena Mountains Ecosection lies leeward of the Skeena Mountains Ecoregion. It has wide valleys with high isolated mountains.
• The Manson Plateau Ecosection is a rolling upland, that lies south of the higher Omineca Mountains. Moist, warm air often flows into the area from the southwest.
• The Parsnip Trench Ecosection is a wide intermountain plain that lies between the Omineca Mountains to the west and the Rocky Mountains to the east. Warm, moist air flows in from the south and cold Arctic air move south down the Northern Rocky Mountain Trench.
• The Southern Omineca Mountains Ecosection consists of rounded mountains and ridges, separated by wide valleys. It has the driest climate in the Ecoregion.

 

• The Skeena Mountains Ecoregion is a bold mountain range lying to the east of the coastal climates and mountains. This Ecoregion consists of two Ecosections.

• The Northern Skeena Mountains Ecosection consists of high rugged mountains and a moist, coast/interior transition climate. Many glaciers persist especially in the north.
• The Southern Skeena Mountains Ecosection consists of a narrow range of mountains to the east of the Nass Basin and the west of the Nechako Plateau. The climate is variable being wetter and milder on the west side and drier and colder on the east side.

Southern Interior Mountains Ecoprovince

Location - This Ecoprovince lies east of the southern interior plateaus in the southeastern portion of the province. It consists of four main physiographic systems: the highlands on the western flank, the Columbia Mountains, the Southern Rocky Mountain Trench, and the Continental Ranges of the Rocky Mountains on the eastern flank.

Climate - There are two distinct climate regimes - one in the mountains and the other in the Southern Rocky Mountain Trench. Air masses approach from the west and lose moisture, first as they pass over the western Columbia Mountains, and again as they pass over the Rocky Mountains. The Southern Rocky Mountain Trench bisects two large mountain blocks with significantly different physiography and macroclimatic processes. During the summer, intense surface heating creates strong updrafts in the hills. The resulting downdraft over the centre of the valley clears the skies and enhances the sunny conditions. During the winter and the early spring, the trench serves as an access route for outbreaks of cold, dense Arctic air.

Biogeoclimatic Zonation - Vegetation is dominated by three zones; the Interior Cedar - Hemlock Zone in the lower to mid slopes of the Columbia Mountains and wetter localities in the Rockies and trench, the Engelmann Spruce -Subalpine Fir Zone occurs on the middle slopes of all mountains and the Alpine Tundra Zone occurs on the summits of those mountains. The Ponderosa Pine Zone occurs in the Southern Rocky Mountain Trench, as does the Interior Douglas-fir Zone, but this zone also occurs sporadically in the main valley of the Shuswap and Okanagan highlands. The Montane Spruce Zone occurs in the valleys and lower slopes of the southern Rocky Mountains and eastern Purcell Mountains, while the Sub-Boreal Spruce zone occurs in the upper Fraser River watershed.

Fauna - Mountain goats are perhaps the most widely distributed wild ungulate in the Ecoprovince but mule and white-tailed deer are also widely distributed. Elk ("Rocky Mountain") are very abundant throughout the mountains and valleys adjacent to the southern portion of the Trench. Small, relict populations of caribou occur in old-growth spruce forests in the Northern Park Ranges Ecosection and the Columbia Mountains and Highlands Ecoregion; the "Selkirk Herd" is the southern most population of caribou in the province. Grizzly and black bears are common throughout the area. Bighorn sheep are common in the Southern Park Ranges Ecosection and adjacent trench.

Small mammals include the long-eared myotis, pika, hoary marmot, Columbian ground squirrel, golden-mantled ground squirrel, and water vole.

This Ecoprovince supports 70% of the bird species known to occur in British Columbia and 62% of all breeding avifauna of the province - the second highest diversity of breeding species. It contains the only breeding location of Forster's Tern and one of the highest breeding concentrations of Ospreys in the world. It is also one of the few areas in British Columbia where the Western Grebe and Long-billed Curlew breed. The Black-billed Cuckoo occurs regularly. Significant autumn and winter populations of waterbirds, especially American coots, are found on large ice-free lakes. The extensive waterbodies are important migration staging areas for Tundra Swans, Canada Geese, and dabbling and diving ducks, particularly redhead. The area is the centre of breeding abundance for the White-breasted Nuthatch. Large flocks of Clark's Nutcracker appear in the valley bottoms during autumn and winter.

The painted turtle, and common and western terrestrial garter snakes are typical reptiles. The long-toed salamander, western toad, and spotted and northern leopard frogs are the characteristic amphibians.

This Ecoprovince supports both anadromous and freshwater fish. Anadromous species include: chinook salmon and white sturgeon. Freshwater fish include: rainbow trout (both native and introduced populations), brook trout (introduced), Dolly Varden, mountain whitefish, mottled sculpin and Yellowstone cutthroat trout.

Ecoprovince Subdivisions - The Southern Interior Mountains Ecoprovince is divided into 7 Ecoregions containing 19 Ecosections.

• The Columbia Highlands Ecoregion is a rolling highland area that rises from highlands and isolated ridges on the west and south to culminate in higher mountains along the northeastern margin. Moist Pacific air rising over these highlands, bring intense precipitation. This Ecoregion contains 3 Ecosections in British Columbia.

• The Bowron Valley Ecosection is a moist cold area, with a wide valley surrounded by low highlands the west and rugged mountains to the east.
• The Quesnel Highland Ecosection is a highland area, intermediate between the plateaus to the west and the high, rugged mountains to the east. Precipitation is higher here than in the Shuswap Highland Ecosection to the south.
• The Shuswap Highland Ecosection is a highland area, intermediate between the plateaus to the west and the mountains to the east. The climate here is warmer and winters are milder than the Quesnel Highland Ecosection to the north.

 

• The Northern Columbia Mountains Ecoregion is a rugged, often ice-capped mountain area that rises abruptly from the Southern Rocky Mountain Trench to the east. This block of mountains intercepts eastward flowing precipitation, making these the wettest mountains in the interior of the province. This Ecoregion contains six Ecosections.

• The Cariboo Mountains Ecosection is an area of high rugged, ice-capped mountains with narrow valleys. It lies at the north end of this Ecoregion.
• The Central Columbia Mountains Ecosection is an area of high ridges and mountains, but the valleys and trenches are narrow. Precipitation is high, from the valley bottoms to the upper slopes.
• The Eastern Purcell Mountains Ecosection is a mountainous area with high valleys. It is located leeward on the Purcell Ranges and is within a distinct rainshadow.
• The McGillivray Range Ecosection is an area of subdued ridges located in the southeast. It is relatively dry.
• The Northern Kootenay Mountains Ecosection is an area of high, rugged mountains, many of which are ice-capped. It has the highest precipitation and coldest temperatures.
• The Southern Columbia Mountains Ecosection is an area of high ridges and mountains interspersed with wide valleys and trenches. Precipitation is high on the mountain slopes but the Creston Valley is in a strong rainshadow.

 

• The Eastern Continental Ranges Ecoregion lies on the east side of the southern Canadian Rocky Mountains. This Ecoregion is represented by only one Ecosection in British Columbia.

• The Front Ranges Ecosection consists of parallel rows of ridges and valleys. Cold Arctic air often lies unimpeded over these mountains, bringing persistent cold temperatures which has resulted in the Alpine Tundra Zone occurring at lower elevations than in the rest of the Southern Interior Ecoprovince.

 

• The Northern Continental Divide Ecoregion is an area of wide valleys and rounded mountains that is interspersed with higher ridges of less erodable bedrock. Cold Arctic air may influence this area from both the Southern Rocky Mountain Trench to the west and the Interior Plains to the east. This Ecoregion contains two Ecosections in British Columbia.

• The Border Ranges Ecosection is a mountainous area of wide valleys and subdued mountains which only occasionally rise to steep, rugged ridges.
• The Crown of the Continent Ecosection is a bold mountainous area that rises abruptly from the surrounding plains, basins and valleys.

 

• The Selkirk - Bitterroot Foothills Ecoregion is an area of rounded mountains and wide valleys. This area lies between the warm moist highlands to the west and wet cool mountains to the east. In British Columbia it is represented by only one Ecosection.

• The Selkirk Foothills Ecosection is a transitional mountain area between the rolling Okanagan Highlands to the west and the rugged portion of the Selkirk Mountains to the east.

 

• The Western Continental Ranges Ecoregion has high, rugged mountains, usually with deep narrow valleys. The climate here is continental. It contains three Ecosections.

• The Central Park Ranges Ecosections is an area of high, rugged mountains, many of which are ice-capped; valleys are often short and steep-sided. The climate is cool and moderately dry.
• The Northern Park Ranges Ecosection is an area of high, rugged mountains, with many ice-capped and moderately wide valleys. The climate is cool and moderately moist.
• The Southern Park Ranges Ecosection is a rugged mountainous area which is dissected by long rivers, forming moderately wide valleys.

 

• The Southern Rocky Mountain Trench Ecoregion is a long wide, flat-bottomed valley that dissects the Southern Interior Mountains Ecoprovince. Cold Arctic air from the sub-boreal part of the province is able to move down the Trench easily, while in the summer months the southern part of the Trench is the driest part of the Ecoprovince. It contains three Ecosections.

• The Big Bend Trench Ecosection is the narrow section in the central part of the Rocky Mountain Trench. Most of the lowland has been flooded by a reservoir. This Ecosection has high precipitation.
• The East Kootenay Trench Ecosection is a broad, flat glacial plain with a distinctive rainshadow that lies in the southern portion of the Rocky Mountain Trench.
• The Upper Fraser Trench Ecosection is a broad, flat glacial plain. The climate is moderately moist and cool, however there is an area with an increasingly distinct rainshadow upvalley from McBride to Valemount. This Ecosection is the northern portion of the Southern Rocky Mountain Trench.

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