Eucalypts dominate most landscapes within Australia. The only landscape they are completely absent from are the highest alpine sites, where conditions are too severe for their survival. They are almost absent from rainforest communities and from the arid interior of the continent, except where they find refuge along streams and in isolated ranges.
Eucalypts have evolved features which enable them to tolerate a wide range of environmental conditions such as bushfires, drought and poor soils. Some of these features include sclerophyll leaves, which are tough and evergreen. Lignotubers and epicormic buds are features which allow eucalypts to continue to grow even after a bushfire.
Eucalypts make up much of sclerophyll forests and woodlands. Both sclerophyll forests and woodlands extend over large areas of Australia more completely than any other plant community in any continent. They are predominantly found in a coastal band, 150 to 600 kilometres wide, from the Tropic of Capricorn to South Australia and Tasmania, but they are also found in smaller areas in south-west Western Australia.
Although the majority of species of eucalypts are endemic to Australia, there are 15 species that occur outside Australia in Papua New Guinea, Timor, Sulawesi and the Philippines. Five of these species occur on Cape York Peninsula and one in the Northern Territory, leaving only nine species that are non-Australian. Although there are red gums in the Mediterranean region and blue gums in California, these trees are the result of introductions from Australia. There are no eucalypts in New Zealand.
It is believed that many of the currently rare or restricted species are heading for extinction, such as E. recurva, on the Southern Highlands of New South Wales. However, other eucalypt species have speciated rapidly and spread widely.
Gwen Harden
Royal Botanic Gardens
Sydney
Copyright © Australian Museum, 2003
This page: http://www.amonline.net.au/factsheets/eucalypts.htm
