The Late Pleistocene and Holocene Vegetational History of Hunter Island, North-Western Tasmania

Abstract

Cave Bay Cave contains pollen-bearing sediments derived partly from weathering of the roof and partly from intermittent human occupation. These span the periods c. 28,000-14,700 B.P. and c. 8000 B.P. to the present. Pollen analysis of the Pleistocene sediments indicates that an initial open shrubland was followed by grassland which became increasingly open with abundant composites. Eucalypts occurred in the area but were probably very sparse. The Holocene section records a coastal shrubland like that at present in the area. Intervals of occupation appear to have had little effect on vegetation recorded at the cave, but fires occurred in the vegetation during unoccupied as well as occupied phases. Comparison of the Pleistocene spectra with those from sites in near-coastal Tasmania and south-eastern Australia suggest that an open grassland with scattered trees was extensive from the Adelaide region down to the Bassian Plain. Some components of this cold steppe formation may occur today in the treeline woodlands on the driest parts of the Tasmanian mountains, but there may also be floristic affinities with arid steppe. The grassland probably reflects conditions colder, drier and possibly windier than any represented in the area today.