Southern Arctic Ecozone
The Southern Arctic Ecozone covers much of the northern mainland of Canada, from the Richardson Mountains in the Yukon Territory to northern Quebec. The Southern Arctic region is the largest of the three arctic terrestrial ecozones, and has the highest species diversity. In the summer, it is green with blooming vegetation – a far cry from the icy barrens of the Far North. The lush vegetation provides food and habitat for many wildlife species.
Long, cold winters and short, cool summers characterize the Southern Arctic climate. Winter temperatures range from -11°C to -7°C, while summer temperatures range from 4°C to 6°C. The long hours of light and milder temperatures result in a longer growing season than the more northerly ecozones and, consequently, more vegetation is able to survive. An annual mean precipitation of 20–50 cm also allows for the "greening" of this ecozone in the spring and summer.
Rolling uplands and lowlands underlain by bedrock create the attractive landscape of the Southern Arctic Ecozone. Eskers up to 100 km long, morainal debris, and other glacial deposits cover much of the area. There are also many ponds and wetlands that serve as important wildlife habitat. Throughout this ecozone, soils are deep, well developed, and have a high nutrient content, because increased moisture and milder temperatures encourage weathering and decomposition. The soil is cryosolic because it is frozen and affected by permafrost. Permafrost is continuous throughout the area, but there are significant active layers that thaw in the summer.
The Southern Arctic Ecozone represents a region of transition from taiga forest to the treeless arctic tundra. Dwarf shrubs decrease in size as latitude increases, because the growing season shortens, the soil is less fertile, and available moisture diminishes. Dwarf birch and willow are among the common shrub species, along with heaths, herbaceous plants, and lichens. Where nutrients and moisture are available along the rivers and streams, scattered clumps of stunted spruce trees grow. Sedges and mosses thrive in the wetlands of the lowland areas of this ecozone and provide important nesting sites for birds. Vegetation is most dense in sheltered areas and depressions, where there is less wind and more moisture. However, plants cover almost the entire landscape in the Southern Arctic Ecozone, making it prime habitat for many wildlife species.
The relatively mild climate and abundant summer vegetation enable a wide variety of wildlife to inhabit the Southern Arctic Ecozone. The summer range and calving grounds for Barren-ground caribou are located here, where there is abundant food. Grizzly bears live in the centre of the region, while polar bears roam the coast. Smaller animals, such as arctic ground squirrels and brown lemmings, coexist with wolves and mink. Migratory birds, including Canada geese and long-tailed ducks, are numerous in the spring and summer, while willow and rock ptarmigans find suitable habitat in the southern Arctic year-round. Like the migratory birds that fly south as winter approaches, other wildlife migrate south to avoid bitter temperatures and the scarcity of resources. Those that remain year-round have thick warm fur and dig through the snow for food.