BBC Bitesize – tundra (polar regions)
BBC Class Clips – flora and fauna in the tundra
BBC Class Clips – flora and fauna in the polar regions
Antarctica and the Arctic have distinctive characteristics
The Arctic Antarctica Climate
- Average summer temperatures <10c
- Winter temperatures around -20c to -40c
- Annual precipitation <500mm
- Winds blow strongly
- Colder than the Arctic
- Summer temperatures around -20c to -5c
- Winter temperatures can reach almost -90c
- Annual precipitation is lower, around 50mm inland and 200mm on the coast
- Windiest continent
Features of the land and sea
- Majority of the Arctic is made up of ocean, lots of drifting ice packs and iceberg. Sea ice extends further in winter
- On land there are mountainous regions, areas that are permanently covered with snow and ice, and areas of treeless tundra (where only a surface layer of the soil thaws each summer)
- Large areas of permafrost (ground which has been frozen for a few years). When the top few centimetres thaw it produces a landscape with many depressions which fill with lakes. Marshland and boggy ground cover large areas. The soil flows when it thaws out and is not stable.
- Continent (land mass) which is 99% covered by an ice sheet
- A few mountains poke out of the top of the ice sheet (nuntaks) e.g. Transantarctic Mountains
- Sea freezes in winter, nearly doubling the size of the continent
Flora and fauna
- Whales, seals, fish, wolves, polar bears, reindeer, caribou and lots of birds
- Most animals have adapted to specific conditions of the Arctic (sub-zero temperatures and absence of liquid water)
- Low-growing shrubs, lichen, moss, some flowering plants e.g. Arctic poppies
- Plants like dwarf willow and lichens cling to the ground surface to avoid being damaged by strong winds.
- Some species have natural ‘anti-freeze’
- Southern fringes of the Arctic have taiga, large expanses of coniferous forest but these disappear with distance north along a line called the tree line
- Less vegetation than the Arctic, there are two species of grass which are found in a few places, otherwise only algae and lichen can survive
- Sea contains lots of phytoplankton
Whales, seals, penguins, sea-birds
- All animals rely on the sea e.g. for food or to provide a habitat for breeding
- Penguins nest on ice shelves and Emperor penguins spend the winter there as well. Most other species migrate north to avoid the extremes of the winter cold
- Marine creatures, including penguins, avoid the extreme temperatures found inland so most biodiversity is found at sea or around the coast
Water and nutrient cycles
