Australia’s biodiversity is important both globally and nationally. It is important to the world because of its uniqueness and its global significance, and it is important to Australians for both moral and utilitarian reasons.
The global importance of Australia’s biodiversity is due to both its richness and its uniqueness, as Steffen et al.1 describe:
Between 7 and 10% of all species on earth occur in Australia. More than 4500 species of marine fishes – and the greatest number of species of red and brown algae, crustaceans, sea squirts, and bryozoans in the world – live in Australian inshore waters. Fifty-seven per cent of all mangrove species are found in Australian intercoastal zones. There are more than twice as many species of reptiles in Australia as there are in the United States, and Australian deserts support more lizard species than any other comparable environment.
The uniqueness of Australia’s biodiversity is largely due to this continent being separated from other land masses for millions of years. In addition, the range and diversity of environmental conditions in Australia is different from most other countries due to characteristics such as nutrient-poor soils, high fire frequencies and a generally flat topography.1-2 Many of Australia’s species, and even whole groups of species that comprise taxonomic families, are endemic (unique) to this continent (Table 8.1). As a result, Australia is identified as one of the world’s ‘megadiverse’ countries (Figure 8.1).
|Marine fish||One of the most diverse fish faunas in the world, with more than 4500 species|
|Sharks and rays||54% of the entire chondrichthyan fauna is endemic to Australia|
|Ectomycorrhizal fungi||95% endemic (22 genera and three endemic families)|
|Terrestrial vertebrates||1350 endemic terrestrial vertebrates, far more than the next highest country (Indonesia, with 850 species)|
|Terrestrial mammals||305 species, of which 258 (85%) are endemic; more than 50% of the world’s marsupial taxa occur only in Australia|
|Birds||17% of the world’s parrots occur in Australia—more than 50 species (second-highest level of endemism after Brazil and the same as Colombia)|
|Reptiles||89% endemic; some groups such as front-fanged snakes (family Elapidae), pythons and goannas are more diverse than elsewhere in the world; Australian deserts have the world’s highest diversity of lizard species|
|Frogs||94% endemic; around 230 total species of amphibians in Australia (highest level of endemism of any vertebrate group in Australia)|
|Marine invertebrates||17.8% of the world’s crustaceans, 22% of bryozoans and 29.4% of sea squirts occur in Australian waters|
|Vascular plants||91% of flowering plants are endemic; 17 580 species of flowering plants, 16 endemic plant families (the highest in the world) and 57% of the world’s mangrove species|
|Butterflies and moths||Many groups are unique to Australia|