- Arctic tundra biome is the northernmost biome.
- Covers the lands north of Arctic Circle to polar ice cap.
- Reaches as far south as Hudson Bay area of Canada and northern part of Iceland.
- Tundra biome has the least vegetation.
- In fact, word “tundra” comes from Finnish word tunturi, meaning ‘treeless plain.’ One important characteristic of the tundra is the permafrost.
The word permafrost is short form for permanently frozen soil, which starts within a meter of soil surface. In winter, almost all the soil is frozen.In summer, soil near surface thaws, but permafrost at lower depths remains frozen.Permafrost limits how far roots of plants can extend down into the soil.It also is what prevents trees from growing.
- Temperatures range from 15.5 °C in summer to -60 °C in winter and mean temperatures are below 0°C for six to 10 months of the year.
- Northernmost part of this biome receives close to 24 hours of sunlight during parts of summer. It receives close to 24 hours of darkness during parts of winter.
- Annual precipitation is around 150 to 250mm a year.
- Vegetation of Tundra biomes is ‘cryophytes.’
- Due to cold climate and short growing season, most vegetation in tundra tends to be herbaceous including grasses, mosses such as reindeer moss, lichens.
- The few woody plants which live in the tundra, such as dwarf willows.
- Plants in this biome also tend to go dormant during the long winters. This means that they slow down their normal life functions.
- Most of their biomass is below ground.
- Plants have tendency to stick to the ground because of temperature inversion.
- Tundra has (i) resident animals (ii) migrant animals.
- Resident animals have relatively larger size and such body structures which allow them to survive severe winters.
- Many large mammals, such as caribou, polar bears, arctic foxes, and musk ox, are found in this biome.
- Also, several smaller mammals, such as lemmings and arctic hare which are prey to larger mammals.
- These prey animals have brown fur in the summer and white fur in the winter to help them camouflage with the changing landscape.
- Although there is low insect biodiversity, the insects that live in the arctic tundra, such as mosquitoes, can have large populations.