Transport of Driftwood from South America to Tasmania and Macquarie Island

Abstract

IN February 1955, a log about 10 ft. long and 5 ft. in girth was found washed up on a sandy beach just inside Port Davey harbour on Tasmania's south-west coast. It was lying between two logs of Huon Pine (Dacrydium franklinii Hook f.), an endemic conifer of Tasmania. Unlike these logs which were well covered with marine growth it was free from such growth although the surface was ‘woolly’ with many pebbles embedded in it. The ends of the log were sawn and one end grooved for towing by a wire rope. The wood was identified from its anatomy as a species of Nothofagus, which genus is represented in Tasmania, the south-eastern portion of the Australian mainland, New Zealand, New Guinea, New Caledonia and South America¹. Anatomically the genus can be divided into two easily distinguishable groups, the one covering the species of New Guinea and New Caledonia, and the other the remaining species². The log in question was derived from the second of these two groups and, because of the presence of spiral thickenings in the vessel elements, its specific identity could be narrowed down to one of three possibilities, namely, N. moorei (F. Muell.) Krasser of northern New South Wales and south-eastern Queensland, N. pumilio (Poepp. and Endl.) Krasser and N. obliqua (Mirb.) Oerst. from South America. The spiral thickenings in N. moorei differ from those of the two South American species; those of the unknown resembled the thickenings observed in the South American species. Both N. pumilio and N. obliqua are restricted to South America, the former occurring from Tierra del Fuego north to latitude 36° S. on the western side of the Andes. N. pumilio, N. antarctica (Forst.) Oerst. and N. betuloides (Mirb.) Oerst. are logged commercially in the southernmost tip of the continent³. All the anatomical evidence thus pointed to a South American origin of the log in question although this conclusion met with some initial opposition.