Fire in the Rainforest: Ancient Fire Regimes in the Northeast Queensland Wet Tropics Bioregion
La Trobe University
Åsa Ferrier, La Trobe University
Fleur King La Trobe University
Simon Haberle, Australian National University
Lincoln Steinberger, Australian National University
Laurence May, La Trobe University
Patrick Moss, University of Queensland
Ron Stager, La Trobe University
Recent catastrophic fires in eastern Australia have highlighted the brutal effect on Australia’s unique ecology and human populations. Although these natural events have a million-year-old history (Dodson et al. 2005), the higher frequency and magnitude of recent fires are signs of increasingly drier conditions due to anthropogenic induced climate change. Identifying the ignition sources and intensities of ancient fires is more difficult because interactions between fire, Aboriginal management and climate change are complex. While some researchers have discounted Aboriginal people as a force shaping Australia’s vegetation (Mooney et al 2011; Williams et al. 2015; Egloff 2017), others have argued that smaller scale, isolated, patchy anthropogenic burning across the continent is highly influential in structuring vegetation (Jones 1969; Bird et al. 2012; Bliege Bird et al. 2016; Zeanah et al. 2017). Clearly the role of fire as a force for vegetation change is a multifaceted process shaped by historical contingency (Williams et al. 2009:24). It follows then that ignitions from anthropogenic and natural sources operating at different spatial and temporal scales (McWethy et al. 2017; Roos et al. 2019).
Unlike the dominant continental savanna-sclerophyll vegetation, tropical rainforests do not burn easily. Therefore, any evidence of fire in Australian rainforests invites explanations of its source. Analysis of one hundred and eighty-five radiocarbon dates and selected charcoal fragments from 23 soil pits and 7 archaeological sites from the Wet Tropics Bioregion, northeast Queensland, suggest a strong relationship between natural and cultural firing regimes over many millennia. Results from our collaborative research challenge previous notions that rainforest experienced a reduction in firing through the Holocene (Hopkins et al. 1993, 1996) and throws new light on the origin and continuation of isolated eucalypt forest pockets within Australia’s tropical rainforest.