Author: Michela Mariani, Associate Professor in Physical Geography, University of Nottingham

Increased land management by Aboriginal people in southeastern Australia around 6,000 years ago cut forest shrub cover in half, according to our new study of fossil pollen trapped in ancient mud. Shrubs connect fires from ground cover to the forest canopy, allowing fires to spread and intensify quickly. The reduction in shrub cover, linked to evidence for increasing population size and more widespread landscape use by Aboriginal people, would have dramatically decreased the potential for high-intensity bushfires. We also found the shrub layer in modern forests is even greater than it was 130,000–115,000 years ago, when the climate was similar…