Distribution and palaeogeography of two Mallee species of Eucalyptus in Southern Australia

Abstract

The present distributions of Eucalyptus diversifolia and E. incrassata are described and disjunctions indicated. It is suggested that a former continuous distribution of both species has been fragmented by rising sea-levels in the Quaternary, and that E. diversifolia was more widespread during a period of lower effective rainfall than the present. It is proposed that Quaternary sea-level changes are of importance in the interpretation of the palaeogeography of plant and animal species with disjunctions in the Nullarbor and Roe Plain area. The nature and role of edaphic barriers to migration in this area are also assessed.