Vegetation and fire response to late Holocene human occupation in island and mainland north west Tasmania

Short sections of organic lagoon sediments have been obtained from two coastal localities, one at Sundown Point on the northwest coast of Tasmania and the other from Stockyard Swamp, 3 km inland on Hunter Island about 60 km to the north. Both sites are infilled swales of transgressive dune fields and provide records of vegetation and fire over the past 4000 yr. Sundown Point has sustained moderate levels of burning until around 2000 BP when a general increase occurs until the time of European occupation. Coastal heath vegetation with eucalypts was maintained until clearance of the area for pasture. Stockyard Swamp has a distinct phase of high carbonised particle accumulation from 4000 to about 2500 BP. This is followed by moderate to low levels of charcoal to the surface. Increased woody vegetation is associated with the higher carbonised particle phase. These prehistoric vegetation and charcoal sequences may reflect a possible correlation with the intensity of human occupation. The high charcoal phase at Stockyard Swamp appears to coincide with a period of possible abandonment of Hunter Island by Aborigines hypothesised from archaeological records. By comparison to the mainland Tasmanian site which experienced presumed continuous occupation after 3000 BP, Hunter Island would appear to have experienced a more variable fire regime after 2800 BP, which may reflect larger but less frequent natural fires, or occasional visits. A steady state on mainland northwest Tasmania was greatly upset by the arrival of the Europeans.