Terrestrial Ecozones

Canada has defined a hierarchical system of ecosystems. At a simple level there are 20 ecozones ecozones, consisting of 15 terrestrial and 5 marine units. The terrestrial part of Canada is further subdivided into 53 ecoprovinces and 194 ecoregions ecoregions. Regardless of the level in the hierarchy, each unit is distinguished from others by its unique mosaic of plants, wildlife, climate, landforms and human activities.

Brief Descriptions of Canada's 15 Terrestrial Ecozones

Forests of Canada cover in total about nine ecozones. The vegetation that covers each of them is briefly described below.

• Arctic Cordillera: Located in the extreme north of Canada, this region is composed of a vast mountain chain with glacial sceneries. In fact, ice and rock dominate 75% of the Arctic Cordillera. The extreme cold, high winds, and the lack of soil make the area devoid of plants and animals. The variations in daylight over the course of the year are considerable.
• Northern Arctic: This ecozone encompasses most of the arctic islands. The landscape consists of low rolling plains covered by permanent frozen ground (permafrost) and by glacial rock debris. The vegetation is generally sparse and stunted. Daylight variations over the course of a year are considerable.
• Southern Arctic: This ecozone is bounded to the south by the treeline, a broad ecological division between the taiga forest and the treeless arctic tundra. The terrain is undulated with many lakes and ponds that have been formed by the melting glaciers of the last glaciation. Permafrost covers the whole ecozone. The summers are short, cool and moist. The winters are long and extremely cold. Total annual precipitation is less than 250 millimetres in the western part of the ecozone and there is rarely more than 500 millimetres in the eastern part. Low precipitation and extremely low winter temperatures stunt tree growth in this ecozone.
• Taiga Plain: The relief of this ecozone consists of broad lowlands and plateaus. Its climate is characterized by short and cool summers followed by long and cold winters. The ground is covered by snow and ice for six to eight months each year. The northern taiga forest covers this ecozone.
• Taiga Shield: The relief of this ecozone is composed of massive rolling hills, formed by the rock of the Canadian Shield. Summers are short and cool and winters long and cold. The snow covers the ground for six to eight months a year. Precipitation is low to moderate. Low temperatures, a short growing season, thin acidic soils, permafrost and frequent forest fires result in an open stunted forest dominated by a few highly adaptable tree species.
• Taiga Cordillera: The terrain of this ecozone consists of a series of ridges and narrow valleys. The climate is cold and humid with long winters, and short and cool summers. Snow covers the ground more than six months a year, and the soil is permanently frozen. Four main vegetation zones are found in this ecozone: alpine tundra zone, subalpine transition zone, montane zone (characterized by spruce-lichen woodlands and flat benches of lodgepole pine), and finally, spruce-feathermoss forests zone with riverside communities of balsam poplar, willow, and alder.
• Hudson Plains: The Hudson Plains are characterized by a flat and poorly drained terrain covered by vast wetlands. Permafrost and ground ice keep the soil impermeable promoting the development of wetlands. Vegetation is similar to the arctic tundra and to a larger degree the taiga transitional forests. Trees here are few and far between.
• Boreal Plains: The relief of this ecozone consists of low-lying valleys and plains. Summers are short and warm, winters long and cold. The annual precipitation is greater than the evaporation resulting in surplus moisture. Timber covers 84% of the Boreal Plains and most of the ecozone is associated with the boreal forest.
• Boreal Shield: This ecozone is covered with a multitude of lakes and contains about 10% of all Canada's freshwater. The land is well irrigated. The terrain is a massive rolling plain of ancient bedrock. The climate is continental with long cold winters and short warm summers. Precipitation is abundant. Boreal forest, mixed with innumerable bogs, marshes and other wetlands, covers this ecozone.
• Boreal Cordillera: This ecozone encompasses the northern Rocky Mountains with massifs and plateaus. The climate is a subalpine type with long and cold winters and short and cool summers. Higher in altitude, above the treeline, climatic conditions are alpine type and high-elevation areas, which are covered with ice and permanent snow. Lower elevations are generally forested by White Spruce and Subalpine Fir. Upper elevations are dominated by deciduous stunted shrubs.
• Pacific Maritime: Bordering the Pacific Ocean, the high summits of the Coastal Mountain chain dominate the area. In this ecozone, there are different kinds of environment: large fjords dissect the coast, glaciers cover the high summits, rocky coastal plains alternate with beaches, and heavy rainfall, combined with year-round mild temperatures, support the vitality of temperate rain forest located on the lower lands of the area.
• Montane Cordillera: Most of the ecozone is rugged and mountainous. In the north, plains are prevalent and extend out as intermontane valleys towards the southern half of the ecozone. There are several kinds of ecosystem: alpine tundra, dense conifer forests, dry sagebrush and grasslands. Winters are cool and wet; summers are warm and dry.
• Prairies: The relief of the Prairies is generally subdued. Its low-lying valleys and plains are sloping eastward. Farmland dominates. However, a water deficit characterises the area because the annual precipitation is extremely variable and considerably lower than other parts of Canada. High winds also accelerate evaporation. Few deciduous trees and shrubs grow in the ecozone except in the eastern regions, in urban areas, along waterways and locations at upper elevations.
• Atlantic Maritime: This ecozone is located at the northeast end of the Appalachian Mountain chain and consists of highlands, peninsulas and islands. The Atlantic Ocean creates a moderate, cool, and moist maritime climate. Winters are long and mild, the summers are cool. Seventy-six percent of the ecozone surface area is covered with forests.
• Mixedwood Plains: This ecozone has abundant freshwater resources, including four of the Great Lakes - Superior, Huron, Erie, and Ontario - and the St. Lawrence River from Kingston, Ontario to Quebec City. The climate is characterised by relatively warm summers and cool winters moderated by surrounding water bodies. Its relief is nearly level with gently rolling plains but broke up by striking physical features which are the Monteregian Hills. This ecozone is the most populated and the most productive of Canada. Agriculture is performed on the richest and most fertile soils. Forest exploitation and recreational activities are pursued in the northern part of the ecozone where the soil is less suitable for crops.

• Land Cover Map | Read about this map
• Tree Species by Ecoregion Map | Read about this map
• Wetlands and Forests Map | Read about this map
• Plant Hardiness Zones Map | Read about this map
• Forested Ecozones Map | Read about this map

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