A VEGETATION HISTORY AND QUANTITATIVE ESTIMATE OF HOLOCENE CLIMATE FROM CHAPPLE-VALE, IN THE OTWAY REGION OF VICTORIA, AUSTRALIA

A well-dated pollen record from Chapple Vale in the north of the Otway region provides a detailed history of vegetation and environments thr ough the last c. 7000 years. From the commencement of the record, a st and of cool temperate rainforest, dominated by Nothofagus cunninghamii (Hook.) Oerst., grew on or around the site and was surrounded by euca lypt-dominated tall open forest. Between c. 5200 and 4600 years BP (be fore present), the rainforest declined and tall open forest predominat ed. Some time after 4400 years BP there was a major and consistent inc rease in charcoal values, suggesting an increase in burning, the progr essive development of scrub-heath vegetation on site and the replaceme nt of tall open forest vegetation by eucalypt woodland surrounding the site. The fossil evidence for N. cunninghamii on the site and its pre sent restriction to wetter areas and gullies of the Otway Ranges indic ate, from the application of the present bioclimatic range of the spec ies, a mean annual temperature and winter temperatures that were c. 1 degrees C cooler than present, and summer temperatures that were possi bly slightly cooler than present, together with a much higher effectiv e precipitation from the commencement of the record until c. 4600 year s BP. These climatic estimates are in accord with those derived from a similar study of changing distributions of N. cunninghamii in the Cen tral Highlands of lower mean annual and cooler summer temperatures and higher effective precipitation over this time span. However, for wint er, the evidence is equivocal. While the Otway estimates suggest lower temperatures, the Central Highlands findings show slightly higher tem peratures. Taking into account additional present-day records for N. c unninghamii, it is likely that the Otway estimates are the most reliab le.