THE ROLES OF COASTLINES, PEOPLE AND FIRE IN THE DEVELOPMENT OF HEATHLANDS IN NORTHEAST TASMANIA

Pollen analysis of a core taken from a reed marsh in northeastern Tasm ania near Bass Strait highlights the interplay between climatic change s, sea level rises and the effects of Aborigines during the Holocene. Prior to 10,000 BP the region formed part of the Bassian landbridge wh ich connected Tasmania to the Australian mainland. Vegetation at that time was characterized by shrubby grasslands with a very sparse tree c over. After 9000 sp, Eucalyptus forests prospered until about 6000 sp. A combination of salt spray from a stabilizing mid-Holocene coast, th e progressive effects of soil podsolization and burning by Aborigines, eventually favoured the replacement of grassy Eucalyptus forests by A llocasuarina with an increasingly heathy understorey. The treeless hea ths dominated by dwarfed Allocasuarina which presently dominate the ar ea are regarded as part of a degradation sequence in which the above f actors are implicated.