Hydroclimate reconstructions from <em>Araucariaceae</em> trees in tropical and subtropical Queensland (Australia) – A case study utilising a multi-technique approach — Australian Meteorological and Oceanographic Society
  1. Schedule
  2. 26(i). The story of water and climate in Australia: past variability and lessons for the future
  3. Hydroclimate reconstructions from Araucariaceae trees in tropical and subtropical Queensland (Australia) – A case study utilising a multi-technique approach

Hydroclimate reconstructions from Araucariaceae trees in tropical and subtropical Queensland (Australia) – A case study utilising a multi-technique approach (#71)

Heather A Haines 1 , Nathan B English 1 , Quan Hua 2 , Jon M Olley 3 , Patricia S Gadd 2 , Jonathan G Palmer 4 , Justine Kemp 3
  1. School of Health, Medical and Applied Sciences, Central Queensland University, Townsville, QLD, Australia
  2. Australian Nuclear Sciences and Technology Organization, Lucas Heights, NSW, Australia
  3. Australian Rivers Institute, Griffith University, Nathan, QLD, Australia
  4. School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia

Many parts of tropical and subtropical Australia lack long-term instrumental climate data and annually-resolved terrestrial proxy climate records. This limits our understanding of past climate patterns and impacts. There are however, remnant forest stands where dendroclimatology can be applied to extend the climate record. Early studies of tropical Australian tree species described the difficulty in obtaining reliable dating from tropical species. This has led to such species being avoided or ignored with little known about their paleoclimate potential. Our recent research of trees in the Araucariaceae family is an attempt to re-address part of this gap in research by developing annually dated records of precipitation in tropical and subtropical Australia.

 

Araucariaceae trees are commonly found across northern and eastern Australia and are longer lived than many other local non-temperate species. They produce growth rings that are annual and their growth appears sensitive to climate, specifically to moisture conditions.  Two Araucariaceae species, hoop pine (Araucaria cunninghamii) and bunya pine (Araucaria bidwillii) have been studied within the Queensland rainforests. Ring anomalies including false, faint, locally absent, and wedging rings, were identified enabling an absolutely dated tree-ring chronology to be produced. A multi-technique approach was used that included bomb-pulse radiocarbon dating, radiographic analysis, and density pattern assessment in combination with traditional ring-width measurements. Additionally, dendrometers were installed on trees of both species to verify the annual growth cycle as well as determine the growth-climate relationships and seasonal response of tree growth. The results demonstrate the possibility for dendrochronology in Australia to be applied for high-resolution hydroclimate reconstruction. Following this, a 164-year drought reconstruction for Southeast Queensland was developed using hoop pine trees from the subtropical rainforest of Lamington National Park. Additional research is aiming to develop a tree-ring chronology network along the east coast of Queensland for analysis of more regional-scale climate teleconnections.

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