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What is biodiversity?
What is biodiversity?

Biodiversity is another term for the variety of nature. A more technical definition, as provided in The National Strategy for the Conservation of Australia's Biological Diversity (Commonwealth of Australia 1996) is:

The variety of life forms, the different plants, animals and micro-organisms, the genes they contain, and the ecosystems they form. It is usually considered at three levels: genetic diversity; species diversity; and ecosystem diversity.

The concept of biodiversity embraces the various living parts of the world around us. The three levels of biodiversity – species, genetics and community – are interrelated and interdependent. A population of a species is dependent on the genetic variation within it and upon its habitat (ecosystem) for survival, and an ecosystem is dependent on the full variety of the species that comprise it (Williams et al. 2001).

Species diversity

Most people are familiar with biodiversity at the species level. Species diversity is "the variety of species on earth" (Commonwealth of Australia 1996) where a species is defined as "a group of plants, animals or micro-organisms that have a high degree of similarity and generally can interbreed only among themselves to produce fertile offspring, so that they maintain their 'separateness' from other such groups" (Williams et al. 2001). In Australia and in south-western Western Australia in particular, new species are frequently being discovered and the taxonomy (naming and description) of species is constantly changing. Over time, our knowledge of species diversity will continue to grow and so will our understanding of what is required to protect these species.

In the past, biodiversity conservation has focused on the protection of individual species, especially those that have currently been determined to be naturally rare or threatened with extinction from a range of processes. Governments compile lists of various species of plants and animals (and occasionally fungi) that are considered rare or threatened, for special protection under legislation or policy. These lists reflect various levels of concern and proposed protection mechanisms. For example, in Western Australia the most rare or threatened species are listed as Declared Rare Flora (DRF) or Specially Protected Fauna and are protected under the Wildlife Conservation Act 1950. At the Commonwealth level, threatened species and communities are listed and protected under the Environment Protection and Biodiversity Conservation Act 1999. The challenge of local biodiversity planning is to look beyond the rare and keep the common, common.

Genetic diversity

Genetic diversity is "the variety of genetic information contained in all of the individual plants, animals and micro-organisms that inhabit the earth. Genetic diversity occurs within and between the populations of organisms that comprise individual species as well as among species" (Commonwealth of Australia 1996). Genetic diversity within species can be documented by the designation of races, variants, subspecies, varieties or forms of a particular species. For example, jarrah is known to have a green-leafed form on the coastal plain and a blue-green form on the Darling Plateau (Powell 1990). Genetic diversity is discovered through detailed studies and there is much work still to be done in this area.

Ecosystem diversity

Ecosystem diversity is, "the variety of habitats, biotic communities and ecological processes" (Commonwealth of Australia, 1996) present across the landscape. The conservation of ecosystem diversity is the most strategic way to conserve all levels of biodiversity (genetic, species and ecosystem) and aims to prevent these elements of biodiversity reaching the point where they become threatened. A method used to describe ecosystem diversity is the ecological community concept. For more information on measuring and describing biodiversity, see the Local Government Biodiversity Planning Guidelines (Perth Biodiversity Project, 2004).

Western Australian Local Government Association

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