A Holocene pollen record from cool temperate rainforest, Aire crossing, the Otway region of Victoria, Australia

Abstract

We present a palynological record from the Otway region of Victoria that covers about the last 9000 years. The record was obtained from a small, remnant, riverine patch of cool temperate rainforest dominated by the southern beech species, Nothofagus cunninghamii, and surrounded by tall open eucalypt forest. The present nature and extent of forest vegetation had been established by the beginning of the record and, in line with other records from southeastern Australia, there is evidence for higher precipitation than today during the mid-Holocene from a slight expansion of rainforest and increased diversity of tall open forest vegetation. From 4300 years ago, forest vegetation around the site becomes more open allowing the establishment of herbaceous swamp taxa. This development is attributed to relative stability of the site, with a reduction in stream water flow. A major feature of the record is the presence of pollen from the southern conifers Podocarpus, Phyllocladus and Dacrycarpus whose parent plants were important components of Victorian rainforest vegetation during the Tertiary period but no longer grow in the Otway region. Although it is considered that these plants were unlikely to have been present in the Holocene, it is proposed it is most likely that they survived within the region until the late Quaternary, possibly until the arrival of Aboriginal people.