The 2016 Tasmanian Wilderness Fires: Fire Regime Shifts and Climate Change in a Gondwanan Biogeographic Refugium

Abstract

Tasmania is rich in endemic, ancient lineages of plant and animal species, which form distinctive communities. These species are restricted to cool, wet environments where fire is very rare. Although protected in the Tasmanian Wilderness World Heritage Area, these palaeoendemic species are threatened by climate change, which is increasing fire activity because of more dry lightning storms and drought. In January 2016, lightning storms ignited numerous fires which destroyed about 1% of the current distribution of the endemic, slow-growing conifer Athrotaxis cupressoides. A. cupressoides is fire-sensitive, and burnt stands are unlikely to fully recover because mortality is high, there is limited seedling establishment, and scarring of trunks renders surviving burnt trees more vulnerable to subsequent fires. Securing the survival of palaeoendemics like A. cupressoides requires costly management interventions, such as use of firefighting chemicals dropped by aircraft, establishing cut or irrigated firebreaks to protect stands from wildfires, and widespread planned burning to reduce fuel loads in flammable vegetation surrounding palaeoendemic refugia. Such intensive management is at odds with the concept of a self-sustaining ‘wilderness’. This has raised profound philosophical questions and ongoing political discussion, about acceptable responses to the impacts of climate change on this world heritage area.