Our fauna is highly endemic (that is, many Australian species are found nowhere else on Earth). About 90% of our reptiles and frog species are endemic, and about 80% of our mammals and 85% of flowering plants (SEAC, 1996). We have 200 species of freshwater fish, 90% of that are endemic. Also, of the 600 species of fish found in the southern temperate zone, about 85% are found only in Australian waters (SEAC, 1996). Conversely groups of animals and plants found in many other countries are not found naturally here. Hooved animals, cats, canids (foxes and Dingos) and plants like thistles, for example, have been introduced and affected native biodiversity (ABS, 2003). .
With over 15,500 species, Australia has more native higher plants (mainly flowering plants,) (ANBG, 1998) than all of Europe (which has 12,500 species), and Queensland and Western Australia each contain around 7,500 native species (ANBG, 1998). New species are still being discovered, like the Nightcap Oak, a large tree discovered in 2000 in northern NSW. There are possibly 10 times the number of cryptogams (fungi, algae, lichens, mosses, etc.) than higher plants, and we have barely begun to understand them (Mill & Hall, 2000). .
Change, such as evolution, and disturbance are a natural part of every ecosystem. But human activity almost invariably affects the direction and pace of change and the extent of disturbance, challenging the ability of ecosystems and species to respond (Saunders et al, 1990). Over the past 200 years, change in Australia has, by world standards, been great and rapid, and has had a profound effect on our biodiversity. The change has taken many forms, including large scale land clearance and the introduction of many exotic species, while the use of water, primarily for agriculture, has damaged the health of freshwater ecosystems (ABS, 2003).
The changes since 1788 have had far-reaching effects on biodiversity.