| Abstract: | In the last few years there has been a marked growth of interest in the recent history of climate. The evidence of secular variations in climatic parameters during the last few centuries has implications for ecologists studying forests containing long-lived species. Such species record aspects of past climate in their annual growth-rings and in their population structures. The study of annual growth rings in Australian trees is still in its infancy. The concepts and techniques of dendrochronology and its sub-fields dendroecology and dendroclimatology are outlined. A species by species account of dendrochronological studies employing Australian trees is presented. As most of the results are unpublished, the treatment is selective and intended to illustrate the potential of, or progress with, a particular tree species. The greatest potential for dendrochronology in Australia lies with the endemic Tasmanian conifers in the genera Athrotaxis, Dacrydium and Phyllocladus. Not only do these contain very long lived individuals (e.g. > 2000yr, Dacrydium franklinii) but also they have the most suitable ring characteristics. Chronologies of about 1000 yr and 780 yr are being prepared for A. cupressoides and Phyllocladus aspleniifolius respectively. There is good regional cross-dating within species, and to a lesser extent between species, giving promise of a detailed reconstruction of past climate for Tasmania. Relatively short chronologies may be developed on the mainland using Callitris. This species may provide a proxy rainfall record for semi-arid areas which would be invaluable to their future management. The possibilities for developing chronologies using long-lived tropical rain-forest species in Queensland are discussed. The most abundant tree species of the continent as a whole, in the genera Eucalyptus and Acacia, appear to be generally unsuitable for standard dendrochronological methods aimed at climatic reconstruction although there are some exceptions. For many dendroecological studies Eucalyptus will be the only species available, and it should certainly not be disregarded. |
