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Aim This paper documents reconstructions of the vegetation patterns in Australia, Southeast Asia and the Pacific (SEAPAC region) in the midHolocene and at the last glacial maximum (LGM).

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We present a reconstruction of the vegetation history of the last glacial-interglacial cycle (ca. 75 k cal. yr BP-present) at Redhead Lagoon, an enclosed lake basin in coastal, eastern New South Wales, Australia. The sequence of vegetation change at the site is broadly comparable with the pattern of climatically induced changes observed in many other pollen records in southeast Australia. Open woodland-herbland and woodland-forest communities correspond with glacial and interglacial periods respectively, with an additional change towards a more open understorey vegetation assemblage over the last 40 000 yr. The driest conditions appear to have occurred during the height of the last glacial (some time between 30 and 20 k cal. yr BP). This is consistent with other records from southeast Australia, and provides support for a poleward shift in the subtropical anticyclone belt and, less certainly, for the thesis that the Southern Hemisphere westerlies intensified during this period. In marked contrast to most sites in southeast Australia, Casuarinaceae dominates the pollen record through the height of the last glacial period and into the Holocene. The postglacial climatic amelioration is accompanied by the general reappearance of tree pollen in the record, by the disappearance of several open and disturbed environment indicator taxa, by increases in organic sediment deposition and pollen taxon diversity, and by higher water balances. While climate appears to have been the major control on patterns of vegetation change at this site throughout most of the last glacial-interglacial cycle, changes in depositional environment and hydrology have also played a role. Significantly, substantial increases in the rate and magnitude of many indicators of environmental disturbance since European settlement suggest that humans are now the most important mechanism for environmental change.

An analysis of diatom assemblages, Total Organic Carbon (TOC), carbon-nitrogen ratio, δ13C, biogenic silica and carboniate in two marine sediment cores from Ellis Fjord, eastern Anitarctica, reveals episodes of climatic change at 3600, 2500. 2000 and 1000 yr BP. Using the diatom data, principal component analysis, the fast-ice index (FI), benthic index (BI) and snow index (SI) (which are derived from the diatom data). a period of reduced temporal sea-ice cover is identified prior to 2500 BP. There was a large increase in sea-ice extent between 2500 and 2000 BP followed by a smaller decline. Tenmporal sea-ice extent after 2000 BP was still significantly greater than prior to 2500 BP. Both cores xvere taken from anoxic basins within the fjJord. It was found that the better preservationi allowed the recognition of taxa such as Clraetocelos vegetative cells, which are inot usually preserved. This enabled the distinction between ice-edge blooms, dominated by Fragilariopsis curta, and open-water blooms dominated by Chaeitoceros. Even though Watts Basin receives a significant summer meltwater input each year, it has not been possible to recognize this signal in the sedimiient core.

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