The Arctic tundra

The constellations Ursa Major and Ursa Minor (Latin for 'great bear' and 'little bear') permanently dominate the firmament of Canada's Far North. Because of their constant presence, the region that lies within the boreal polar circle is called 'Arctic,' since the Greek word for 'bear' is arktos.

The Arctic ecozones, which have the lowest precipitation in Canada, encompass the Arctic islands as well as the northern portion of the continent from the Yukon to Labrador. This is the land of intense cold, where average annual temperatures range between –17^oC and –7^oC, depending on the region. In February 1979, meteorologists at Eureka Station on Ellesmere Island calculated an average monthly temperature of –47.9^oC, which still stands as a record for Canada. In such conditions, it is not surprising to find permafrost, ground that remains frozen all year long, sometimes to a depth of several hundred metres.

Polar bear on tundra, Churchill, Man. ©2003 ICN-RCI / Hemera

This is the land of the tundra, a word that comes from the Finnish word tunturi, meaning 'barren land.' And barren is certainly what this land is—in some places. But farther south the vegetation becomes less sparse. And when the fine weather comes, when the sun shines even at night, the soil thaws at its surface and a carpet of plant life quickly appears upon the desolate landscape. Flowers such as mountain avens, saxifrage and the Arctic poppy dot the ground with spots of colour that are as dazzling as they are ephemeral. A few shrubs, such as the Arctic willow, occupy the most favourable locations, while lichens flourish on surfaces scorned by other plant life. Lichens, strange assemblages of a fungus and an alga, are ubiquitous in the Arctic tundra, where they play a crucial role in enabling caribou to survive the long winter.

While these lands seem highly inhospitable, they nevertheless nourish a variety of wildlife well suited to the harsh climate and scarce resources. The caribou gather here in large herds, while wolves and foxes wander over great distances in search of prey. Cosily warm under its tattered coat of fur, the musk-ox tirelessly roams the tundra in search of a few blades of plant life. The polar bear, for its part, prefers the edge of the ocean, where it can feast on fish and marine mammals such as seals. The Arctic waters teem with walrus, beluga whales and narwhals, and in the mating season, this region is home to vast numbers of migratory birds, including snow geese and Canada geese. A very few birds have chosen the tundra as their permanent home, although they sometimes make journeys south when driven by hunger. The snowy owl, thanks to its plumage, can survive at temperatures of –50^oC.