A new study has uncovered when and why the native vegetation that today dominates much of Australia first expanded across the continent. The research should help researchers better predict the likely impact of climate change and rising carbon dioxide levels on such plants here and elsewhere. The dominant vegetation, so-called C4 plants, includes a wide variety of tropical, subtropical and arid-land grasses. , C4 plants also include important worldwide crops such as sugarcane, corn, sorghum and millet. The research has just been published online in the journal Geophysical Research Letters.