Australian Acacia species around the world: historical, social, evolutionary and ecological insights into one of the planet's most widespread plant genera

Acacia is the largest and most widespread genus of plants in the Australian fora, occupying and often dominating a wide range of habitats on that continent and exhibiting an equally diverse range of forms and life-history traits. All but 17 of the currently recognized 1082 species in the genus have native ranges entirely within Australia. Many Australian Acacia species ('wattles') have been introduced to other parts of the world and planted for many purposes since the 18th century; at least 41% of all wattle species are known to occur as non-native species in 172 countries. Some species are commercially important as forestry trees, others are widely planted for sand stabilization or revegetation, used in different forms of agroforestry, planted as ornamentals, or provide other benefts. At least 75 species have established self-sustaining populations outside their native ranges and 28 are invasive, in many cases causing substantial ecological and socio-economic impacts. This chapter provides the background and context for the other 30 chapters in this book that explore numerous aspects of the history, biogeography, sociology, ecology and evolution of Australian Acacia species in the native range and around the world.