Australian Alps

The high altitude peaks and plateaus, glacial lakes and alpine and sub-alpine ecosystems of the Australian Alps are rare in the mostly flat, dry and hot continent. They contain the highest peaks in the Great Dividing Range. The Alps are of outstanding landscape significance and are important in the pattern of Australia’s natural history. The Kosciuszko Plateau includes the most striking examples on the Australian mainland of landforms created by glaciers. The Alps are home to unique cold climate plants and animals.

The soil types are diverse with the majority being of granite (53%), basalt (22%) and soils formed from an eroded material (for example shale and slate – 25%). Most are naturally acidic and not very phosphorous. The granite and

slate/shale soils are characterised as being generally rough in texture with low water-holding capacity and low fertility. The basalt soils have a higher water-holding capacity and higher fertility. The Alpine ecosystem has a wide range of both native and introduced flora and fauna. Some examples of flora are Snow Gums, Box Wood, Pine, Wallaby and Kangaroo Grass, Native Geranium and over 500 different types of grass. In addition some examples of alpine fauna are Wombats, Echidnas, Kangaroos, Emus, Deer, Cattle, Copperhead and brown snakes, Frogs, Kookaburras, Gang-gang Cockatoos, Wedge-tail Eagles, Hawks and Falcons.

The atmosphere of the alpine ecosystem is generally cold, and it is has high levels precipitation.

Snow normally falls the most during June, July and early August. Most of the snow has melted by late spring. Annual rainfall is between 500-600mm. The average summer temperature is 28 degrees and the average winter temperature is 11 degrees.

The relevant water system in the hydrosphere of the alpine ecosystems is the Snowy River. This is because it is a major river that runs through the Australian Alps in south-eastern Australia. It originates on the slopes of Mount Kosciuszko, Australia’s highest mainland peak, draining the eastern slopes of the Snowy Mountains in New South Wales, before flowing through the Alpine National Park and the Snowy River National Park in Victoria and emptying into Bass Strait.

Introduced animals compete with native animals for food and shelter and they kill native plants and animals. Non-native animals may also introduce disease, such as the disease Toxoplasmosis passed on to native animals by cats. Hard-hoofed animals and animals that dig, cause extensive soil erosion. Feral pigs, for example, upturn the soil to feed on roots and bulbs and also like to wallow in bogs. This damages the banks of bogs that shelter frogs and other animals. Muddy water reduces the visibility for animals, smothers eggs and gills and changes the oxygen levels in the water. Foxes sniff out and eat small, ground-dwelling native mammals amongst rock piles and logs. Foxes also

like to live in these places, taking up the available living spaces necessary for native mammals to shelter in.

Animals living at the higher elevations have to deal with a long, cold winter season when food is scarce, temperatures are low and the ground is covered with snow.

In addition there are not many trees to provide a suitable habitat. Animals have adapted to cope with this harsh environment. One strategy is to live entirely under the snow during winter. As snow falls and covers the vegetation a space exists between the ground in which small mammals can move and search for food. Temperatures remain constant under the snow even though they vary greatly in the open air. The Mountain Pygmy Possum, the native Bush Rat, and Swainson’s Antechinus all survive in this way. During the coldest part of the season some animals hibernate or go into torpor. In both cases the animal’s metabolism shuts down almost completely and only the essentials are kept functioning. Hibernation is long-term and induced by a seasonal trigger. However, Torpor is short term and a means by which an animal is able to reduce energy use by lowering its metabolism. Its body temperature can drop to near that of its surroundings. The Mountain Pygmy Possum hibernates during the coldest part of the season. There is also communal living and nesting, some species of lizards have been found hibernating in groups of more than a hundred in the centre of Snow Gum logs during winter. Lastly, Migration is a strategy mainly used by birds and flying insects. Less than half the species of birds found in the summer month’s stay

during winter. Species such as the Pink Robin, the Flame Robin and the Pied Currawong move to lower altitude areas.

Plant adapt to the natural stress of cold and seasonal climate of alpine areas they live in.
Some plants are annuals with a short life cycle of rapid growth, flowering and seed production. They survive winter as a seed, which will grow the following spring. Many plants have renewal buds close to the ground where they are protected from cold by soil and plant litter. Shrubs have a very slow growth rate, the stems of feldmark Epacris increase in diameter by 0.27 mm/yr. Many shrubs have a rock clinging habit because rocks retain warmth