Palynological evidence for Holocene palaeoenvironments from the lower Gordon River valley, in the World Heritage Area of southwest Tasmania

Abstract

A Holocene palaeoenvironmental history from the World Heritage Area of southwest Tasmania is reconstructed using an 8000-year palynological record from Lake Fidler, a small meromictic lake adjacent to the lower reaches of the Gordon River. The sequence indicates that cool temperate rainforest has remained dominant in the region for at least the last 8000 years, confirming the wilderness value of this important conservation area. There is little evidence for fire in the region throughout this period and no discernible evidence for anthropogenic impact until approximately 1815 when small-scale convict logging activities commenced along the Gordon River. The record demonstrates the long-term presence of stands of one of the world's oldest living trees, Huon pine (Lagarostrobos franklinii), with significant increases in this species in the mid-to late Holocene. This expansion is evident in several Tasmanian records and is associated with declines in other important Tasmanian plant species. It is proposed that it represents a regional phenomenon possibly related to climate change. Examination of the climate signal from other Australian Holocene pollen records provides some support for this interpretation.