About the Catchment Area : Plants and Animals

Biodiversity
Biodiversity or biological diversity refers to the variety of lifeforms on this planet - its plants, animals, microbes and fungi, the genes that they contain and the ecosystems of which they are a part.

The term is also often used to describe the diversity of organisms within a particular area or range. This 'local' biodiversity is of concern when human activity encroaches on habitat and pushes species out of the area or in some circumstances causes local or complete extinction of a species.

All organisms rely on other lifeforms for their existence. Organisms using oxygen in respiration rely on plants for its production and food comes from plants, animals and fungi. Any change in numbers of one species will effect the lives of other species. Habitat degradation in the form of landclearing or introduction of foreign species is the main cause for losses in biodiversity.

World agricultural trade depends on biodiversity. New varieties of livestock and crops are being bred continually from their wild 'cousins' in order to stay ahead of pests and diseases. These are being used to breed drought resistance, to boost nutritional content or to increase crop yields. Many common pharmaceuticals were first found in wild plants and animals and major searches are continuing around the world for new therapeutic compounds in wild species.

Australia is in a fairly unique position in the world as it contains a huge variety and number of species (an estimated 475,000 of the earth's 10 to 30 million species). Australia is one of only 12 'mega diverse' countries and the only one which is considered a 'developed' country. One striking example of this is a comparison of a hill in Canberra known as Black Mountain with The United Kingdom. Black Mountain is home to more species of ants than exist in the whole of the UK.

It has been estimated that about 500,000 hectares of native vegetation are cleared each year in Australia. This human intervention in the physical landscape along with the introduction of species such as rabbits, foxes, cane toads and sparrows has been detrimental to Australia's biodiversity. There is much to be done in order to halt and reverse this trend. Conservation of the biological diversity within our ecosystems underpins Australia's economic and social health. These ecosystems depend on conservation management by landholders, communities and all levels of government so as to develop ways of using resources without compromising Australia's natural heritage. Australia has contributed to the International Convention on Biodiversity and has in place a national strategy for the Conservation of Australia's Biological Diversity.

Information sourced from the CSIRO - Fact Sheet on Biodiversity. http://www.csiro.au/index.asp

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Threats to Biodiversity

Worldwide, more than 10,000 species become extinct each year and while precise calculation is difficult, it is certain that this rate has increased alarmingly in recent years. The central cause of species extinction is destruction of natural habitats by human beings.

Many indigenous human cultures have also been driven to extinction by the same forces which have destroyed and continue to threaten non-human species. It is estimated that since 1900 more than 90 tribes of aboriginal peoples have gone extinct in the Amazon Basin.

Nearly every habitat on earth is at risk: the rainforests and coral reefs of the tropics, the salt marshes and estuaries of our coastal regions, the tundra of the circumpolar north, the deserts of Asia and Australia, the temperate forests of North America and Europe, the savannahs of Africa and South America.

Tropical rainforests, for example, are among the most diverse of all terrestrial ecosystems. Covering only 7% of the planet's surface, these forests comprise 50-80% of the world's species. 40 million to 50 million acres of tropical forest vanish each year -- about 1.5 acres per second -- as trees are cut for lumber or land is cleared for agriculture or other development. It is estimated that perhaps a quarter of the Earth's total biological diversity is threatened with extinction within 20 to 30 years.

There are no easy answers, but part of the solution lies in increased educational efforts. Steps can be taken to develop sustainable resources. Rich and poor nations alike must strive toward a wise and cooperative stewardship of global biodiversity. Communities and nations who wisely preserve their biological resources must see tangible returns for their efforts.

Information sourced from the CSIRO - Fact Sheet on Biodiversity. http://www.csiro.au/index.asp