Antarctic terrestrial ecosystem
Antarctica is not just a land of ice and snow – it is the coldest, driest climate on earth. When we say the word ‘desert’, we might imagine sand and camels, but in fact a desert is any place that receives less than 25 centimetres of rain in a year, making Antarctica a large cold desert. Not all of Antarctica is covered in snow – some of the inner regions of Antarctica (called the Dry Valleys) have large areas of uncovered rock.
The connection between organisms within ecosystems can be described based on whether they are producers or consumers of energy.
Who are the producers?
Antarctica has no trees or shrubs but it is far from being lifeless. Plants living in Antarctica must overcome two major factors: the cold temperatures and the lack of rainfall – they must have a regular water supply or the ability to go dormant for periods of time.
Lichen
Lichen is formed by a symbiotic relationship between algae and fungi. Fungi protect the algae from drying out and supply it with water, whereas the algae undergo photosynthesis providing carbohydrates to the fungi. This relationship means that they are formed into a single plant-like form allowing them to live in very harsh environments.
Lichen on rocks
Despite seeming like a barren landscape, Antarctica has many lichen species. This photo shows how lichen can colonise the rocks of Torgersen Island in the Antarctic Peninsula.
Algae
There are an estimated 300 species of non-marine algae in Antarctica. They are found in many different locations, from the sea edge to living inside rocks in the dry valleys.
Mosses and liverworts
These plants have the special ability to dry up completely and become dormant, only to return to life when water is available. They grow in groups called colonies – this increases their water gathering ability.
Flowering plants
Only two species of flowering plants (Antarctic hair grass and Antarctic pearlwort) are found, quite often seen growing together in sunny and sheltered areas.
Who are the consumers?
Native animals are mainly invertebrates (like insects) and birds.
Springtails
Springtails are small insects that have earned their name because of their ability to leap or spring using their tails. They live on rocks and in the soil, from Antarctica’s dry valleys up to mountain peaks.
Invertebrates
Insects, worms, snails, mites and spiders are all animals that are invertebrates (they have no backbone) found in Antarctica. Many of them live parasitic lifestyles, feeding off birds. Others burrow into the soil, like the worm species. Some of the worms are actually decomposers, others are predatory animals.
Nematodes
These worms (called nematodes, or round worms) are around 1 mm in length and live in Antarctica’s soils. This species called Panagrolaimus davidii can freeze and then come back to life.
Birds
Many bird species can be considered both terrestrial and marine, and some migrate between Antarctica and the sub-Antarctic regions or from even further away.
The most famous and numerous of the Antarctic birds are penguins, with seven species living on/around Antarctica. They breed on land but feed in the ocean on krill and fish. They are also preyed upon by other birds, seals and whales.
Antarctic skua
The South Polar skua is the most southerly bird in the world. Although they live around the coastal edge of Antarctica, they have been seen flying over the South Pole which is more than 1,575 km from the coast. The skuas usually nest near penguin colonies where they prey on unattended eggs or weak or isolated penguin chicks.
Other bird species include albatross (a large bird with a three-metre wingspan that is fast approaching extinction), skua, petrels, gulls and terns. Most of the birds either feed on fish and krill or prey upon young chicks of other birds.
Who are the decomposers?
Bacteria, fungi and some worms all act as decomposers in this terrestrial environment, breaking down dead plants and animals in order to use their nutrients.
