Climate change and the impacts of extreme events on Australia's Wet Tropics biodiversity

[Extract] This project proposes to provide information and tools to enable scientists and management agencies to predict and limit the impacts of extreme climatic events on Australia's biodiversity. It aims to determine the exposure, sensitivity and vulnerability of Wet Tropics biodiversity to climatic extremes, and assess contemporary and future impacts. Landscape-scale exposure will be mapped by determining relationships between broad-scale macro climate and direct measurements of organism exposure in different environments. Microhabitat-scale exposure will be determined by combining the microhabitat preferences of Wet Tropics biota with the thermal characteristics of their known preferred habitat. Landscape-scale and microhabitat-scale exposure will be combined to map accurately temperatures experienced by organisms in-situ. Sensitivity of Wet Tropics biota to temperature extremes will be determined by integrating information on their thermal tolerance limits, their resilience, and their capacity to adapt. Thermal tolerance limits have already been quantified by the James Cook University researchers for a range of representative taxa. Using validated methodology, data on thermal physiology of an additional 25 key taxa will be collected in-situ. Resilience will be quantified from known traits that affect a species’ ability to survive and recover from an environmental insult. The capacity to adapt will be estimated by comparing the thermal characteristics of a species’ most favourable microhabitat with that of its other viable habitats. The three types of information will then be combined to obtain highly accurate estimates for the sensitivities of a range of representative Wet Tropics species. The project will explicitly incorporate the correlative and, where possible, mechanistic links between exposure and sensitivity to model spatiotemporal variation in current and future vulnerability to extreme temperature events. This will enable the mapping of impacts of anthropogenic changes in the regimes of temperature extremes on the distribution, abundance and extinction risk of species, something that has not been attempted before in any region. The project will initially concentrate on the regimes of temperature extremes; however, analytical approaches will then also be applied to the regimes of other extreme climatic events, particularly droughts and wildfires as they are strongly linked to extreme heat events. The ultimate aim is to develop a generalised framework for assessing the vulnerability of any natural system to any extreme climatic event. This will be critical for informing proactive conservation strategies that minimise biotic vulnerability to such events in the face of climate change. Project outputs at a glance Accurate high resolution maps of the exposure to temperature extremes as experienced by organisms in-situ. Accurate estimates of the sensitivities of organisms to temperature extremes. Identification of the areas where biodiversity is currently most vulnerable to temperature extremes ('thermal hotspots'). Identification of the areas where biodiversity is least vulnerable to temperatures extremes in the future ('thermal refugia'). A list of biodiversity values particularly at risk from extreme events. A generalised analytical toolkit for assessing vulnerability to extreme climatic events in Australia and elsewhere. Specific objectives and intended outputs of this Project are detailed in the NERP TE Hub Multi-Year Research Plan