Studies on the Status of Unburnt Eucalyptus Woodland at Ocean Grove, Victoria. II. The Differential Seedling Establishment of Eucalyptus ovata Labill. And Casuarina littoralis Salisb

Abstract

At Ocean Grove, Vic., Eucalyptus woodland which has remained unburnt for many years is being replaced by Casuarina scrub. Neither poor germination or poor seed supply is responsible for the lack of eucalypt regeneration. However, ants harvest substantial numbers of eucalypt seeds, but not those of Casuarina. Furthermore, powdered cladode litter of Casuarina littoralis delayed germination of Eucalyptus orata substantially, but not that of its own seeds. Survival and establishment of young eucalypts is prevented by the dense grass sward, while establishment of C. littoralis, C. Stricta and Acacia pycnantha is not greatly hindered. Removal of the sward by firing promoted establishment of eucalypts. Successful establishment of A. pycnantha seedlings in the sward is largely due to vigorous early growth of roots and shoots as a result of its larger seed size. Survival of C. Littoralis in the sward is not due to rapid early development of roots and shoots, but is probably due to greater shade tolerance and/or drought resistance.