Introduction
Return to Our Living Wealth contents
| Australians are the custodians of some of the most diverse ecosystems on the planet. Our continent is one of the world’s 12 biologically ‘megadiverse’ regions, with a high proportion of endemic species — those that are found nowhere else in the world. For example, 93% of our marsupial species and 88% of our native rodents are endemic. Victoria’s land area supports a wider range of broad ecosystems than any area of a similar size in Australia: alpine, mallee, grasslands and grassy woodlands, forests, heathlands and heathy woodlands, inland waters and estuaries, and coasts. These ecosystems have evolved over many thousands of years as a result of the effects of variations in geology, geomorphology, rainfall and climate on the flora and fauna present in ‘Australia’ when ancient Gondwana separated into the modern continental land masses. The uplifting of the southern highlands around 3 million years ago and the subsequent long period of erosion, stream-building and deposition, provided the conditions for the development of the diversity of terrestrial ecosystems now present in Victoria. |  |
Victoria’s marine ecosystems occupy the shallow margins of the northern edge of Bass Strait. At its limit (three nautical miles offshore) the water depth varies from 30 m to just over 100 m. Many of the features of the current coastline and sea floor reflect the cumulative effects of processes that began with the breaking up of Gondwanaland 50 million years ago, especially changes in sea level over the last 100,000 years. The 30 or more bays, inlets and estuaries along the coast were formed by the inundation of coastal river valleys after the end of the last Ice Age.
The western Victorian coast bears the full brunt of the southern ocean storms and experiences some of the highest wave energy in the world. The eastern coast is sheltered from these storms by Tasmania and the shallow waters and islands of Bass Strait, and receives some of the warmer currents that flow south along the eastern Australian sea board.
Victoria’s natural ecosystems support at least 3140 native species of vascular plants, 900 lichens, 750 mosses and liverworts, 111 mammals, 447 birds, 46 freshwater and 600 marine fish, 133 reptiles, 33 amphibians, and an untold number of invertebrates, fungi and algae. This richness — in the number of different ecosystems and different species, and the genetic variety they exhibit — is what we call biodiversity. It is a scientific, cultural, spiritual and economic inheritance that is distinctly Victorian, and one that we must conserve and manage for future generations.