What is biodiversity?
Biological diversity – or biodiversity – is the term given to the variety of life on Earth. It is the variety within and between all species of plants, animals and micro-organisms and the ecosystems within which they live and interact.
Biodiversity comprises all the millions of different species that live on our planet, as well as the genetic differences within species. It also refers to the multitude of different ecosystems in which species form unique communities, interacting with one another and the air, water and soil. 1
Biodiversity is explored at three levels:
• genetic diversity
• species diversity
• ecosystem diversity.
Biodiversity in Australia
Australia was once part of the great southern landmass Gondwana, which also included South America, Africa, India and Antarctica. Gondwana began to break up around 180 million years ago, with Australia eventually splitting from Antarctica about 45 million years ago.
Australia is home to large numbers of species that occur nowhere else in the world. Over 80% of our plants and mammals, and 45% of our birds live only here. These unique species have evolved largely due to Australia’s long isolation from other continents and their adaptation to Australia’s varied environments and changing climate.
Australia is identified as one of the world’s 17 “megadiverse” countries. The concept of megadiversity is based on the total number of species in a country and the degree of endemism, or the extent to which organisms are unique to that country. Together, these 17 countries harbour more than 70% of the Earth’s species.
Of those megadiverse nations Australia and the USA are in the highest income category, with well developed economies, and the resources needed to deal with environmental problems.
This presents an opportunity for us to demonstrate world leadership in biodiversity conservation and to provide a high standard of biodiversity protection across our continent.
1. Swingland, I. R. 2001. Biodiversity, Definition of. Pp. 377-391 in Encyclopedia of Biodiversity, Ed S. A. Levin. Academic Press, San Diego.