The Antarctic ecozone includes the continent of Antarctica, and various islands in the Southern Ocean, South Atlantic and the southern Indian Ocean, such as South Georgia and the Kerguelan Islands.
Millions of years ago, Antarctica was part of the ancient supercontinent of Gondwanaland and had a warmer, wetter climate supporting a distinct community of woody vascular plants known as the Antarctic flora. By 30-35 million years ago Antarctica was isolated geographically and climatically and the much colder climate caused the Antarctic flora to died out in Antarctica.
Today Antarctic krill is the keystone species of the Southern Ocean, and is an important food organism for whales, seals, Leopard Seals, fur seals, Crabeater Seals, squid, icefish, penguins, albatrosses and many other birds.
Coastal cliffs are the rocky land edges that face the sea. These are complex and diverse habitats that lie above the water line, where exposure to salty spray, wind, sun and rain all play their part, as does the type of rock.
Polar regions, found at the planet's northern and southern extremes, are the icy wastes of the continental ice caps and the frozen pack ice of the ocean. The only 'plants' here are specialised forms of cold-loving algae that grow on the surface of snow.
Tundra is the cold, treeless region around the poles that has permafrost as one of its defining features. Even at the height of summer, the soil a few centimetres under the surface remains frozen.