Last glacial to Holocene evolution of semi-arid rangelands in southeastern Australia

Abstract

Pollen sequences from playa lakes in the Darling Anabranch dunefields of southwestern New South Wales record vegetation changes over the last glacial period and into the Holocene. This interval was one of marked taxonomic and structural reorganization, with the plant communities that became established after the last glacial maximum (LGM; ~24-18 ka) distinct from those that had prevailed over the build-up to full glacial conditions (~70-24 ka). The glacial period was characterized by a gradual reduction of woodland and tall shrubland cover. Recolonization of the dunefields involved a similar, gradual succession from herbfields and low shrublands to tall shrublands and, finally, woodlands. These changes are likely to have been driven by climatic change, particularly fluctuations in temperature, precipitation and atmospheric CO2, as global climate systems entered and emerged from the last glaciation.