The toundra

Green : The borealie Dotted : The artic toundra

Espèces : Canada goose Musk ox Wolverine Woodland caribou  Gray lichen Tundra swan Trumpeter swan Snowy owl Snow goose Polar bears Artic fox

The Tundra is the northern limit of the Taiga. It is a biome that is characterized by long, dark winters and very short summers lasting less than three months. The average temperature for the warmest period does not go above 10oC.  In fact, it is not rare that snow falls in the middle of July. Because of these conditions, the earth never completely thaws on this territory. The upper layer of soil thaws down about one metre (3 ft.) whereas the lower layer remains frozen. This is what is known as permafrost and goes down several metres. Total precipitation is variable, from 200 to 600 mm (8 in. to 2 ft.). The climate is more generally dry and cold.^1,2,3

Climatic conditions mean that plant life grows very slowly and remains stunted, partly in order to avoid drying out through wind and cold. In the southern part of the biome, one may find bushes, but further north, one meets up with only herbaceous crops, lichens and mosses. ^1,2,3  Growth is slow but, on the other hand, plant life expectancy may be very long, some lichens being over 100 years old. ¹

Plant growth takes place over the short summer period when there is almost perpetual sunshine. This intense plant production attracts many birds that come to the area to mate; these include the Canada goose, the snow goose, the eider duck and many other species.  Resident birds include the snowy owl and the spruce grouse. The tundra is one of the rare terrestrial biomes where you will find large droves of animals, amongst them the caribou, famous because of the huge herds and its migratory behaviour. The tundra is also home to musk oxen, polar bears and smaller mammals such as wolves, Arctic foxes and lemmings. The most noticeable members of the insect family are, of course, mosquitoes and black flies! ^2,3

There are many who believe that the tundra has remained untouched by human beings. However, one has to note the increase in petroleum exploration and the impact this has on the environment. Moreover, we can also observe the surreptitious advance of pollutant chemical particles brought thither by the winds. Indeed, atmospheric pollution of major North American and European cities inevitably drifts northwards.3  This illustrates clearly that our way of living does not only affect our own environment, but that of the whole planet.