65 OVERLAND TRANSPORT OF LEAVES IN TWO FOREST TYPES IN SOUTHERN VICTORIA, AUSTRALIA AND ITS IMPLICATIONS FOR PALAEOBOTANICAL STUDIES DAVID C. STEART 1,3 , PAUL I. BOON 1* & DAVID R. GREENWOOD 2 1 Institute for Sustainability and Innovation, Victoria University of Technology (St Albans campus), PO Box 14428, Melbourne City Mail Centre, VIC 8001 Australia 2 Environmental Science, Brandon University, 270 18th Street, Brandon, MB, R7A 6A9 Canada 3 Current address: Department of Geology, Royal Holloway University of London, Egham, Surrey TW20 0EX United Kingdom * to whom reprint requests should be addressed, Email: paul.boon@vu.edu.au STEART, D. C., BOON, P. I. & GREENWOOD, D. R., 2006. Overland transport of leaves in two forest types in southern Victoria, Australia and its implications for palaeobotanical studies. Proceedings of the Royal Society of Victoria 118 (1): 65–74. ISSN 0035-9211. The distance that leaves travel from their parent tree has important implications for palaeobotanical studies in which past vegetation types and climates are reconstructed. We quantified the distance moved overland by leaves of five tree species (Acacia melanoxylon, Atherosperma moschatum, Eucalyptus regn- ans, Lomatia fraseri and Nothofagus cunninghamii) in two contrasting, but contiguous, forest types in south-eastern Victoria: a) cool temperate rainforest dominated by Myrtle Beech, Nothofagus cunning- hamii; and b) wet sclerophyll forest dominated by Mountain Ash, Eucalyptus regnans. Regardless of species, leaves generally remained close to their parent tree: 80 % of leaves moved less than 0.2 m over an observation period of six months and the greatest distance moved by any leaf was 3.4 m. Contrary to ex- pectations, slope had little overall effect on leaf transport. We conclude that leaves from trees in these two forest types are transported less than one tree height from their parent tree during normal weather condi- tions. Greater transport may occur during extreme weather, which could promote extensive wind-borne leaf transport from the tree canopy. Keywords: Eucalyptus, Nothofagus, palaeoclimate, taphonomic bias, wind transport, leaves PLANT FOSSILS constitute a fundamental source of information on the evolutionary history of plant lineages, vegetation and climate change, however, taphonomic bias often complicates attempts to re- construct palaeoclimates and past vegetation types. There are three main sources of preservational, or taphonomic, bias in the macrofossil record of plants (Spicer 1981, 1991; Ferguson 1985; Burnham 1989, 1993; Greenwood 1991; Burnham et al. 1992): a) differential production of plant parts (i.e., leaves, re- productive organs and woody parts); b) differential transport and sorting of plant organs among species once they have been shed from their parent plants; and c) differential decay and preservation of plant organs from different species. In earlier papers we reported on differential pro- duction of plant parts (Steart et al. 2005) and differ- ential aqueous transport of leaf material within streams (Steart et al. 2002). In this communication, we focus on differential overland transport of leaves belonging to tree species within two contrasting for- est types. This aspect of taphonomic bias is impor- tant in palaeobotanical studies for two reasons. First, the accuracy with which a fossil-leaf deposit repre- sents the original flora depends partly upon how far the component leaves were transported before burial and preservation (Ferguson 1985; Greenwood 1991; Spicer 1989, 1991). If little or no overland transport occurs after abscission, the leaf fossil record will re- flect more accurately the local tree species than if leaves were moved large distances from their parent plant, or leaves were imported from distant plant communities (Ferguson 1985; Spicer 1989, 1991). Second, if leaves move little after falling to the ground, fossil leaf assemblages should consist mostly of riparian or wetland plant species since these habitats are most conducive to leaf preserva- tion (Spicer 1989, 1991). The prediction is espe- cially important in the Australian context because there is a general paucity of sclerophyll taxa, such as Eucalyptus and Acacia, in the leaf fossil record (Cookson 1954; Christophel 1989; Lange 1982; Hill 1982, 1992, 1994; Martin 1994; Hill et al. 1999; Greenwood et al. 2000; Macphail & Hill 2001). These genera are not commonly considered as ripar- ian. The extent of overland transport of leaves in