The International Day for Biological Diversity held in May 2008, recognised that sustainable agriculture promotes and is enhanced by biodiversity, but that agriculture has also been a major cause of biodiversity loss. To date, the responses to address these declines in biodiversity have been to set up conservation reserve schemes, and (in Australia) legislation to conserve vegetation and threatened species. However, both local and global biodiversity continues to decline at alarming rates (Millennium Ecosystem Assessment 2005). Conservation of biodiversity within agricultural landscapes is essential.

Definitions of biodiversity generally cover all life forms, are vague, and only of limited utility value to the agricultural sector. For example, a classic definition describes biodiversity as, ‘the variety and variability among living organisms and the ecological complexes in which they occur’. Here, biodiversity includes not only biotic but also abiotic ecological processes. A more recent, simpler definition, closely following that of Noss, describes biodiversity as, “the variety of life, its composition, structure and function, at a range of scales”