Overview
'Biodiversity is the complex variety of life that sustains our planet'

Biological diversity or biodiversity refers to the variety of all life on earth - plants, animals and microorganisms, as well as the genetic material they contain and the ecological systems in which they occur. Australia is described as a 'mega diverse country'. In comparison with many other parts of the world we have a vast range of different species, many of which are endemic - species that are only found in Australia. This section includes information on marine and terrestrial threatened species and introduced species as well as terrestrial native vegetation; other marine biodiversity issues are discussed in Coasts and the Sea.

Maintenance of biodiversity is essential to the health and function of environmental systems. Healthy ecosystems are necessary to maintain our atmosphere, climate, clean water and soils.

There are also aesthetic and cultural reasons for maintaining biodiversity. Native plants, animals and ecosystems help define our cultural identity. They contribute to our sense of place and a sense of spirit and are important for supporting our recreational pursuits. Our sweeping landscapes, diverse marine environments and unique ecosystems are essential to how we define our country, ourselves and how the rest of the world perceives us. Conserving biodiversity is also important for ethical reasons - other species have as much right to the earth as humans.

Biodiversity is important economically, for controlling pests and diseases, pollinating plants, recycling nutrients, as well as providing food, clothing and building materials, medicines and many other kinds of raw materials. Biodiversity is also a fundamental basis for tourism.

In South Australia, terrestrial biodiversity has been lost through the fragmentation and degradation of ecosystems due to land clearance, the invasion of pest plants and animals as well as ecologically inappropriate fire regimes. Some species have become extinct and many others are threatened. Marine biodiversity has been lost through marine pollution, habitat destruction and introduced species.

Since European settlement over 80% of the original native vegetation has been cleared in South Australia's agricultural regions. In the remainder of the State, the natural vegetation remains, but has been significantly changed in the 150 years of European settlement.

Conservation of natural areas in terrestrial reserves and Marine Protected Areas continues to improve the level of biodiversity protection. However, given what has been lost, and what we are in danger of losing, we have a long way to go.