Piloting novel multi-centennial palaeoclimate records from mainland southeast Australia.
- 1School of Earth, Atmosphere and Environment, Monash University, 3800, Australia
- 2Fenner School of Environment and Society, Australian National University, Acton 2600, Australia
- 3School of Geography, Planning, and Spatial Sciences, University of Tasmania, Sandy Bay 7005, Australia
- 4School of Ecosystem and Forest Sciences, University of Melbourne, Richmond 3121, Australia
- 5Centre of Excellence for Australian Biodiversity and Heritage, University of New South Wales, Kensington, 2052, Australia
High-resolution palaeoclimate proxies are fundamental to our understanding of the diverse climatic history of the Australian mainland, particularly given the deficiency in instrumental datasets spanning greater than a century. Annually resolved, tree-ring based proxies play a unique role in addressing limitations in our knowledge of interannual to multi-decadal temperature and hydroclimatic variability prior to the instrumental period. Here we present cross-dated ring-width (RW) and minimum blue-intensity (BI) chronologies spanning 70 years (1929 – 1998) for Podocarpus lawrencei Hook.f., the Australian mainland's only alpine conifer, based on nine full-disk cross-sections from Mount Loch in the Victorian Alps. Correlations with climate variables from observation stations and gridded data reveal a significant positive relationship between RW and mean monthly maximum temperatures in winter throughout central Victoria (r = 0.62, p < 0.001), and a significant negative correlation to winter precipitation (r = -0.51, p < 0.001). We also found significant negative correlations between RW and monthly snow depth data from Spencer Creek in New South Wales (r = -0.60, p < 0.001). Of the assessed BI parameters, delta blue-intensity (ΔBI; the difference between early- and late-wood BI) displayed the greatest sensitivity to climate, with robust spatial correlations with mean October to December maximum and minimum monthly temperatures (r = -0.43, p < 0.001; r = -0.51, p < 0.001) and July precipitation (r = 0.44, p < 0.001), across large areas of northern Victoria. These promising findings highlight the utility of this species for future work. With the very limited availability of suitable long-lived and cross-datable species on the Australian mainland, these results have implications for the significant advancement of palaeoclimate records in southeastern Australia and the potential for improvement in our understanding of past climate in the region.
How to cite: O'Connor, J., Henley, B., Brookhouse, M., and Allen, K.: Piloting novel multi-centennial palaeoclimate records from mainland southeast Australia., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6899, https://doi.org/10.5194/egusphere-egu22-6899, 2022.
