This section of the web site has been developed to provide information about what the Adelaide area was originally like and what locally native plants and biodiversity existed.
A Biodiversity Hot Spot
Adelaide was settled by Europeans in 1836. Research has shown that before development and clearing, the Adelaide Plains supported 21 main vegetation types (or associations) ranging from open forests and woodlands to coastal dunes and salt marshes. Over 725 species of native plants and approximately 280 species of bird are known to have occurred in the region (273 in Turner 2001; 285 p 111, 286 p 114 in Adelaide: Nature of a City Eds Daniels & Tait).
What is Adelaide Like Now?
A major report released in 2001 showed that approximately 97.3% of the pre-European settlement vegetation of the Adelaide Plains had been progressively removed as the urban area has expanded (Turner 2001). Mangroves and coastal samphire communities made up three quarters of the remaining 2.7%.
Of the 725 native plants of the Adelaide Plains, 140 or 19% were locally extinct and another 393 or 54% were rare or threatened. They have been replaced by introduced species, and suburbs, factories and roads.
Biodiversity in Adelaide
Much of our present urban flora and fauna is composed of introduced species. Apart from birds, native animals are rare in our suburbs. A few, such as brush-tailed possums, blue-tongued and shingle-back lizards, geckos and the occasional brown snake, have adapted to urban life. Koala, an introduced mammal to Adelaide, in an urban gum treeMany of the original plant and animal species are no longer found, or only occur in much reduced and fragmented populations.
The loss of mammal species from the Adelaide region has been significant. Of the 40 mammal species that lived here prior to 1836, 20 no longer occur and others are threatened on a national level. Since settlement another 12 species of mammal were introduced in the Adelaide region, including the Koala; however one of those is currently extinct (i.e. the wild dog). Nine species of bats still occur in the Adelaide region. They have not suffered the general decline of other mammals, but their numbers may decline if more old and dead trees are lost as they require hollows for roosting and breeding.
Estimations range from 273 to 286 bird species recorded for the Adelaide region prior to settlement, including migratory and introduced species. Current estimations of bird diversity are about the same, though native species have been lost and the region has gained some exotics that have successfully colonised following land clearance for agricultural and urban purposes. Habitat loss has adversely affected many bird populations and some 76 species are regarded as having conservation significance.
51 species of reptiles and amphibians are known for the Adelaide region – 34 lizards, 11 snakes and 6 frogs. Two species – the common death adder and pygmy bluetongue (nationally endangered) – are now locally extinct and others threatened.
Relatively little is known of Adelaide’s insects. Some 190 native species of spider and 63 species of water beetle have been recorded but little is known of their conservation status. 23 species of mosquito have been recorded. 34 butterfly species are known from the region and at least nine are rare or threatened.