Evolutionary biogeography of the Australian flora in the Cenozoic era

The dominant historical pattern of the Australian flora over the last 65 million years is one of contraction of a widespread mesic flora that contained both rainforest and sclerophyll components, and expansion and diversification of dry climate and fire tolerant groups, especially sclerophyllous groups. Many species (perhaps the majority) are from lineages that have existed continuously in Australia since the final break-up of Gondwana. However, this autochthonous flora has been overlain by a complex pattern of migration into and out of Australia, including trans-oceanic dispersal among temperate southern hemisphere landmasses and immigration across land (or island hopping) from Asia. Some major historical biogeographic patterns within Australia seem fairly clear (such as the separation of mesic zones of southwestern and southeastern Australia). However, many other biogeographic patterns and processes within Australia are still very poorly understood.