Taiga Shield
Encyclopedia
The Taiga Shield Ecozone is an ecozone
which stretches across Canada's
subarctic region. Some regions exhibit exposed Precambrian
bedrock
of the Canadian Shield
, the oldest of the world's geological formations. The world's oldest rocks, dating to four billion years, are found in the Canadian Shield north of Great Slave Lake
.
, a tiny corner of northeastern Alberta
, a narrow strip of all northern Saskatchewan
and northwestern Manitoba
, as well as all some parts of southern Nunavut
. Here, it is interrupted by Hudson Bay
, where it abuts with the marine ecozone of the Arctic Archipelago Marine
, and resumes on the eastern shores of Hudson Bay on the coast of Quebec, where it continues in a consistently-wide strip towards the ocean, encompassing all but a small portion of Labrador
. It is one of the largest ecozones in Canada, covering 1.3 million square kilometres.
Terrain is typically flat or rolling hills with thousands of depressions carved by glacial retreat now infilled, forming lake
s, pond
s, wetland
s and other water features. Long esker
s and uplands are also common.
, the Taiga Shield is sparsely populated, with approximately 340,000 inhabitants, over 60% of which is First Nations
. Most settled areas developed around mining
or hydroelectric
activity, for example in Yellowknife and Uranium City in the west and Labrador City in the east, but are isolated from other communities. Mineral extraction is the most important economic activity, with iron
being mined in Quebec and Labrador, uranium
in Saskatchewan, and gold
and more recently diamond
s in the Northwest Territories.
a year in its most northern reaches, and winters that are extremely cold and long, with at least one 24-hour period of complete darkness. Precipitation ranges from 250 to 500 mm (10-20 in.) annually throughout the zone, except in Labrador which may receive up to 800 mm (31 in.) along its coast, and typically increases from west to east.
The shallow soil
s remain damp, even soggy, year-round, and regularly freeze and thaw without drainage. This leads to shifting soil that randomly tilts growing trees, which has been likened to a "drunken forest
".
Ecozones of Canada
The ecozones of Canada consist of fifteen terrestrial and five marine ecozones in Canada. These are further subdivided into 53 ecoprovinces, 194 ecoregions, and 1021 ecodistricts...
which stretches across Canada's
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
subarctic region. Some regions exhibit exposed Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
of the Canadian Shield
Canadian Shield
The Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien , is a vast geological shield covered by a thin layer of soil that forms the nucleus of the North American or Laurentia craton. It is an area mostly composed of igneous rock which relates to its long volcanic history...
, the oldest of the world's geological formations. The world's oldest rocks, dating to four billion years, are found in the Canadian Shield north of Great Slave Lake
Great Slave Lake
Great Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...
.
Geography
The Taiga Shield ecozone covers almost all of the eastern area of the Northwest TerritoriesNorthwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, a tiny corner of northeastern Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, a narrow strip of all northern Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....
and northwestern Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, as well as all some parts of southern Nunavut
Nunavut
Nunavut is the largest and newest federal territory of Canada; it was separated officially from the Northwest Territories on April 1, 1999, via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the actual boundaries had been established in 1993...
. Here, it is interrupted by Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
, where it abuts with the marine ecozone of the Arctic Archipelago Marine
Arctic Archipelago Marine
The Arctic Archipelago Marine Ecozone is a marine ecozone in the Canadian arctic, encompassing Hudson Bay, James Bay, the internal waters and some shores of the islands in the Canadian Arctic Archipelago, and the shores of the territories, northern Ontario and western Quebec...
, and resumes on the eastern shores of Hudson Bay on the coast of Quebec, where it continues in a consistently-wide strip towards the ocean, encompassing all but a small portion of Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...
. It is one of the largest ecozones in Canada, covering 1.3 million square kilometres.
Terrain is typically flat or rolling hills with thousands of depressions carved by glacial retreat now infilled, forming lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, pond
Pond
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens, water features and koi ponds; all designed for aesthetic ornamentation as landscape or architectural...
s, wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s and other water features. Long esker
Esker
An esker is a long winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North America...
s and uplands are also common.
Settlements
Primarily wildernessWilderness
Wilderness or wildland is a natural environment on Earth that has not been significantly modified by human activity. It may also be defined as: "The most intact, undisturbed wild natural areas left on our planet—those last truly wild places that humans do not control and have not developed with...
, the Taiga Shield is sparsely populated, with approximately 340,000 inhabitants, over 60% of which is First Nations
First Nations
First Nations is a term that collectively refers to various Aboriginal peoples in Canada who are neither Inuit nor Métis. There are currently over 630 recognised First Nations governments or bands spread across Canada, roughly half of which are in the provinces of Ontario and British Columbia. The...
. Most settled areas developed around mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
or hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
activity, for example in Yellowknife and Uranium City in the west and Labrador City in the east, but are isolated from other communities. Mineral extraction is the most important economic activity, with iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
being mined in Quebec and Labrador, uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
in Saskatchewan, and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
and more recently diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
s in the Northwest Territories.
Climate
This subarctic zone experiences cool summers that are short, with at least 24 hours of full daylightSolstice
A solstice is an astronomical event that happens twice each year when the Sun's apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes...
a year in its most northern reaches, and winters that are extremely cold and long, with at least one 24-hour period of complete darkness. Precipitation ranges from 250 to 500 mm (10-20 in.) annually throughout the zone, except in Labrador which may receive up to 800 mm (31 in.) along its coast, and typically increases from west to east.
The shallow soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s remain damp, even soggy, year-round, and regularly freeze and thaw without drainage. This leads to shifting soil that randomly tilts growing trees, which has been likened to a "drunken forest
Drunken trees
Drunken trees, tilted trees, or a drunken forest, is a stand of trees displaced from their normal vertical alignment.This most commonly occurs in northern subarctic taiga forests of Black Spruce under which discontinuous permafrost or ice wedges have melted, causing trees to tilt at various...
".