Summary

Australia is a repository of a unique flora once widespread throughout Gondwana, the southern supercontinent. As the connectivity to other landmasses was lost, an indigenous Australian flora evolved in response to changing environmental conditions from prevalently wet to prevalently dry. Although the Tertiary fossil record suggests the continent-wide dominance of rainforest communities, it also documents an adaptive trend towards cooler, drier and more seasonal climates. More recently, the Quaternary saw a succession of glacial cycles that produced transitional plant communities that were considerably different from current ones. On the whole, major natural disturbances and long-term landscape modifications have steadily contributed to Australia’s floristic diversity.

However, the arrival of people has introduced increasing and more rapid pressure on natural habitats through intensive land usage and degradation, as well as the introduction of pests and weeds resulting in a new set of threats to biodiversity. Protecting and conserving species as well as the condition of natural ecosystems is becoming an increasingly pressing concern that requires an integrated approach. Describing the extent and distribution of diversity and endemism is important, but should represent only a preliminary step towards the development of conservation criteria. Biodiversity management is increasingly reliant on our understanding of the relative vulnerability of species and communities to current, past and future threats. As we better understand how species and assemblages respond to temporal changes in environmental disturbance, it will become increasingly possible to explore proactive conservation and restoration strategies.