Biodiversity is the most complex and vital feature of our planet. Biodiversity encompasses the sum and variety of all living things, and all their interactions – including all species of plants and animals, micro-organisms, the genetic information they contain and the ecosystems they form. There are different levels of biodiversity – genetic, species and ecosystem diversity – and all three levels work together to support the complexity of life on Earth. 
The term biodiversity was coined in 1985, as a contraction of ‘biological diversity’. Article 2 of the Convention on Biological Diversity defines biological diversity as:
“the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic systems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems”. 
There are a range of values associated with biodiversity. Ehrlich and Wilson (1991) propose three basic reasons why we should care about biodiversity. The first is most closely linked to intrinsic value – or the moral responsibility to protect our only known living companions in the universe. Their second reason is related to the option value of biodiversity – the potential for humanity to benefit further from obtaining foods, medicines, pharmaceutical and other products from biological resources. Their third reason is based on the recognised ecosystem services provided by natural ecosystems, and the essential role that diverse species play as key working parts within such ecosystems. 
The importance of biodiversity issues regionally, nationally and globally is reflected in Australia’s Strategy for Nature , the Convention on Biological Diversity’s targets for 2020, and in the recent establishment of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). 
 Convention on Biological Diversity, article 2; http://www.cbd.int/sp/
 Ehrlich, P.R. and Wilson, E.O. (1991) ‘Biodiversity Studies: Science and Policy.’ Science, 253, 758-762.