How Australian Aborigines Shaped and Maintained Fire Regimes and the Biota

People proliferated across Australia, which was then a part of Sahul, from about 40 000 years ago when megafauna finally disappeared long before the Last Glacial Maximum. The so called ‘blitzkrieg’ hypothesis proposes that megafauna were extinguished by Aboriginal hunting. It is argued, either that there were some changes in vegetation and fire regimes as a consequence, or that fire regimes and vegetation were largely unaffected by human arrival. However, there is an alternative view that Aboriginal burning changed the vegetation so that megafauna had insufficient food resources to sustain them. We aimed to resolve this debate by examining the published palaeological and historical evidence. This evidence indicates that Aboriginal burning initially turned much biomass into charcoal, reducing browse, changing vegetation and causing megafaunal extinctions. It created ecosystems whose health and safety depend on constant human input of mild fire. Mild burning of these anthropogenic landscapes consumes relatively little biomass and produces relatively little charcoal. Although burning by people has typically been regarded as an ecological disturbance, the historical evidence, together with traditional Aboriginal knowledge, suggests that it is actually maintenance, essential to sustain our natural environment. We conclude that people can reinstate resilient, healthy and safe landscapes irrespective of climate change.