Terrestrial Life

Terrestrial life in the Antarctica is unlike that in all other major regions of the world: the vegetation is composed almost entirely of low lying mosses and lichens, and there are no vertebrate animals (besides birds and seals which depend on the marine environment for food). Even the climatically less severe sub-Antarctic islands possess a very limited tundra-like vegetation of short flowering plants and ferns with very few shrubby species and no trees; apart from a few land birds, only invertebrate animals are native to the region.

The terrestrial environment
Two principal factors have brought about the impoverished flora and fauna. The isolation of the Antarctic and sub-Antarctic regions from other continental land masses has created a sea barrier to immigration by plants and animals, and only ten thousand years ago the region was even more heavily ice-capped and inhospitable.

The second factor is the harsh weather, particularly the cold summer, which prevents the establishment and growth of all but the hardiest plants. If vertebrate animals could find their way here, the short slow-growing vegetation would be insufficient to support most herbivores, and consequently no carnivores could survive; seabirds and seals would be available as food for only part of the year, because of their patterns of migration.

Antarctic terrestrial life, excluding a few species of snow-dwelling bacteria and algae, is restricted to areas which become snow-free for a few months in summer. Such land is mostly in coastal areas and offshore islands where the warming influence of the adjacent ocean creates a slightly more hospitable environment; this applies also to the more alpine sub-Antarctic islands. In many potentially suitable areas vegetation is excluded by dense colonies of penguins or seals.

Vegetation requires a regular supply of water during the summer. This, together with the nutrients dissolved in it, permits limited growth for a few months, rarely longer even in the more northerly regions. Because of warming by the sun's radiation, temperatures at plant level often exceed 20 degrees C. even when the air temperature is well below the freezing point, thereby creating a relatively favorable environment for plants and invertebrate animals.

While both plants and invertebrates can often tolerate long periods of drought and snow cover, many plants are capable of carrying out respiration and photosynthesis below zero degrees, as long as solid freezing has not occurred. Unstable ground, due to the frost heaving and down-hill movement of soil over the permafrost, limits the distribution and continuity of plant communities, while ground exposed to wind and dessication is also sparsely colonized.

Wherever there is vegetation, there is usually invertebrate life, albeit inconspicuous, with the wetter habitats having the greatest diversity and highest numbers. High densities of some invertebrates also occur in the relative warmth and shelter beneath stones and rock crevices.


 • Australian Antarctic Data Centre fact files
Introductory information about Antarctic and subantarctic animals, plants and features.
 • Prehistory
More background information on the prehistory of Antarctica.
 • Antarctic Adventure 1997
Information on the geography and climate of Antarctica.