Fire, humans and climate as drivers of environmental change on Broughton Island, New South Wales, Australia

In Australia, the drivers of precolonial fire regimes remain contentious, with some advocating an anthropogenic-dominated regime, and others highlighting the importance of climate, climatic variability or alternatively some nexus between climate and human activity. Here, we explore the inter-relationships between fire, humans and vegetation using macroscopic charcoal, archaeology and palynology over the last similar to 5430 cal. year BP from Broughton Island, a small, near-shore island located in eastern Australia. We find a clear link between fire and the reduction of arboreal pollen and rainforest indicators on the island, especially at similar to 4.0 ka and in the last similar to 1000years. Similarities with comparable palaeoenvironmental records of fire in the region and a record of strong El Nino (dry, fire-prone) events supports the contention that climate was a significant influence on the fire regimes of Broughton Island. However, two periods of enhanced fire activity, at similar to 4000years BP and similar to<600years BP have weaker links to climate, and perhaps reflect anthropogenic activity. Changes to the fire regime in the last similar to 600 years corresponds with the earliest evidence of Indigenous archaeology on the island, and coincides with implications that Polynesian people were present in the region. After the mid-Twentieth Century a human-dominated fire regime is also an obvious feature of the reconstructed fire record on Broughton Island.