 1. The control of rainforest structure, composition and physiognomy
Rainforest is of particular value in studies of vegetation characteristics because it occurs over a wide geographical range (e.g. equatorial to temperate regions) and also has a long historical record through fossil floras. It can therefore be useful in studies of the environmental determinants of vegetation patterns at scales ranging from local to global, and at temporal scales ranging from ecological to geological. My approach to ecological questions has been to focus on the comparative biology of the organisms. This research comprises two main directions: (a) Factors controlling rainforest composition, diversity and structure: a demographic and ecophysiological approach. This has included long-term research in Tasmania and related forests in New Guinea and New Caledonia. Collaborators are based in Tasmania and New Caledonia. The research has been funded by an ARC Large Grant, ARC Small Grants and a French Government collaborative grant. (b) Factors controlling changes in the composition of rainforest in south-east Australia during the Tertiary. I have also used an ecophysiological approach to try to integrate studies of the biology of those living plants that have a strong fossil record, with historical data, in order to examine the relative importance of various changing environmental factors during the Tertiary on rainforest distribution, composition and physiognomy in the Australian region. This work highlighted the differences in behaviour of species that today only occur in tropical regions, from those occuring today only at high latitudes. It has now become a study of how the fundamental biology varies between tropical and temperate species. This research has been funded by ARC Large Grants and Small Grants. 2.The functional significance of leaf form. Leaf biomechanics is an area of functional ecology that has been relatively neglected, in part because of the technical complexity of measuring these properties, particularly in biomaterials. Our work is focussed in two areas: (a) the mechanical attributes of sclerophyllous leaves in order to provide a firmer base for interpretations of the adaptive significance of this major leaf form, and (b) leaf mechanics as an anti-herbivore defence. This work is undertaken in collaboration with Assoc. Prof. Gordon Sanson. |
