Late Holocene vegetational changes on the Illawarra coastal plain, New South Wales, Australia

Abstract

Palynological evidence is presented which supports the view that Illawarra was not entirely covered by dense rainforest at the time of European settlement. In the environs of Jamberoo and Kiama, there may have been wet sclerophyll forest and subtropical rainforest in existence during the last five millennia of the Holocene. The palynological data are unable to substantiate estimates of the amount of rainforest prior to its clearance by Europeans. However, in view of both the number of pollen and spore taxa from plants now characteristic of regional sub-tropical rainforest, and the almost certain under-representation of these taxa in the palynological record, it is feasible that such vegetation occupied a considerable part of this area, with wet sclerophyll present on less climatically and edaphically favoured sites. Local wetland vegetation dynamics seem to have involved saline being replaced by freshwater marsh c.2600 B.P. The reduction in marine influence responsible for this seral change may have either been caused by a fall in sea-level, or a more effective coastal barrier.