Biodiversity

What is Biodiversity?

Biodiversity comprises the great variety of living things, including plants, animals, fungi, and micro-organisms. It can be considered at various levels of complexity: genes, species, communities, and ecosystems. Biodiversity has evolved, and interacts with, the natural processes that sustain life. It is intricately connected with moderation of the climate, the purification of air and water, the fertility of soils, and the decomposition of wastes.

Biodiversity provides many resources for human consumption. It supplies many foods, fibres, fuels, and medicines, and research is uncovering many new uses for natural products. We also benefit psychologically and physiologically from contact with nature. For example, such contact has proven beneficial in health care. Further, biodiversity is essential in adaptation to environmental change. Variability within species allows their populations to respond to change, with evolutionary processes favouring individuals that are most suited to new conditions.  

Anthropogenic changes to the environment are threatening biodiversity. According to the World Conservation Union, over 16,000 species of plants and animals are currently in danger of becoming extinct. The greatest pressures on biodiversity are from habitat loss, largely due to agricultural and urban development. The global expansion of human populations has led to the pollution and deforestation of many biodiverse habitats.

In Australia, threats to biodiversity include the introduction of exotic pest species like Paterson's curse (Echium plantagineum), foxes (Vulpes vulpes), and rabbits (Oryctolagus cuniculus), the introduction of commercially bred exotic species like sheep (Ovis aries), and changes in water and food sources, which favour some species, like the overabundant eastern grey kangaroo (Macropus giganteus), and create problems for others, like the platypus (Ornithorhynchus anatinus). As noted above, changes in animal and plant communities affect the physical environment. For example, the mangrove woodlands at Port Gawler are changing the coastline as they advance southward, by promoting the build up of sediments and modifying tidal flows.

There is increasing political resolve to improve the conservation of biodiversity, including urban biodiversity. The United Nations Environment Programme was established in 1972 to foster cooperation in environmental research and education to improve the environmental standards of international development. The focus on biodiversity was intensified when, in 1992 at the Rio Earth Summit, the Convention on Biological Diversity was signed by delegates from 150 countries. This convention calls for conservation, sustainable use, and sharing of biological resources. Then, in 2007, the Curitiba Declaration on Cities and Biodiversity was signed, expressing the importance of the contribution that urban areas can make in conserving biodiversity.

Page authors: Philip Roetman and Chris Daniels, 2010.