Almost all plants in the southern hemisphere did not change habitat during millions of years of evolution, according to a study by an international team (Australian National University, University of Queensland, University of Tasmania, Macquarie University in Australia and Chilean researchers, American and Swiss). The study focused on a set of 11,064 species of vascular plants belonging to 45 taxa from Africa (excluding the tropics), Madagascar, Australia, Papua New Guinea, New Caledonia, New Zealand and South America, approximately 15% of the total flora of these regions. Each plant has been associated with one or more of the seven biomes or habitats found in these

regions (sclerophyll biomes, alpine and arid areas, rain forests, marshes, temperate grasslands, savannas), and transitions between biomes were also taken into account. The analysis showed that only 396 species (3.6%) live in a different biome that of their ancestors. Of these, 356 species were on the same continent or even on the island and 40 species are associated with transoceanic colonizations. Most species that have crossed a sea or ocean were in the same type of environment. The frequency of transitions between biomes varies according to their similarity, and no transition was observed between the arid biomes and marshes, or between the savanna and alpine environment. Transitions frequently occurred between the sclerophyll biomes and arid Australia and Africa which are both characterized by vast expanses of oligotrophic soils and are distinguished mainly by their degree of humidity. Overall the movement of species of sclerophyllous biome biomes to arid and alpine meadows and were most numerous. They were held during the last 25 million years, when these systems were expanded. The limited capacity of plants to environmental change suggests that the survival of some species could be affected by the contraction of their biomes, due to climate change.