The bioclimatic domains of four species of commercially important eucalypts from south-eastern Australia

Abstract

Summary A bioclimatic analysis was undertaken for four commercially valuable wood production trees from south-eastern Australia: -Eucalyptus regnans (mountain ash, swamp gum or stringy gum); Eucalyptus delegatensis (alpine ash, white-top stringybark or gum-top stringy bark); Eucalyptus nitens (shining gum or silvertop) and Eucalyptus fustigata (brown barrel or cut-tail). A reference resource for forest managers is presented that includes summary information on a range of bioclimatic conditions which characterise the extant distribution of each tree species. These data were used to map the predicted potential bioclimatic domains of the four species. In each case, areas were identified with marginally suitable bioclimatic conditions that extended beyond the present known distributions of the species, while the core bioclimatic domain of each species often conformed more closely to its known range. The results of our investigation highlighted some clear differences in the bioclimatic regimes occupied by the four targeted taxa. The most marked contrasts were between E.fastigata and the other three species, particularly with respect to seasonal differences in rainfall patterns and annual variations in temperature regimes. E.fastigata typically occurs on sites characterised by lower cool season rainfall compared with the other tree species. Conversely, warm season rainfall was higher for E.fastigata although the differences between the four taxa were not large. Sites supporting E.fastigata experienced a greater range in temperature than those inhabited by the three other species of trees. The approach used in this study has potential value in a range of aspects of forest management including modelling site productivity, designing vegetation surveys, identifying areas to establish plantations, and determining provenances for plantation use.