Late Pleistocene vegetation and climate history of Lake Selina, western Tasmania

Abstract

Abstract Analysis of pollen, NRM intensity of sediments, and dating of a 397 cm core from Lake Selina in western Tasmania provides a detailed record of vegetation and climate changes for the Last Interglacial–Last Glacial cycle. The vegetation record shows that cool temperate rainforest was present during Isotope Substage 5e and during the Holocene. Wet montane forest and subalpine shrublands dominated the early Last Glacial interstades; subalpine–alpine heathlands and herbfield the stadials. Stages 4–2 mainly had grassland, herbland and heath vegetation. There is close correlation between phases of maximum magnetic intensity in the sediments with pollen zones indicating presence of herbaceous vegetation. This suggests erosion of the catchment was greater in the absence of forest or woodland. Climate may have been slightly cooler than present during Substage 5e but the evidence is not definitive. Climate was colder at all times during the Last Glacial Stage until after ca. 14 kyr BP. Maximum temperature depression from present during Stage 2 was >3.5°C at Lake Selina, but probably as much as 6.5°C in the West Coast Range. Holocene climate was cool and wet. Comparison of the Lake Selina record, with others in western Tasmania and Victoria, indicate that variations in vegetation during the Last Interglacial–Last Glacial cycle were primarily responses to temperature changes in western Tasmania, and to precipitation changes, particularly summer drought, in western Victoria.