A Re-evaluation of Queensland?s Wet Tropics based on ?Primitive? Plants

Abstract

The diversity of angiosperms in primitive families, which occur in the Wet Tropics of Queensland, is frequently cited as evidence of the ancient nature of the Australian rain forests, but appears to be based on flawed taxonomic assumptions. We point out the error of identifying species as being primitive rather than representing families with ancient origins, list the families from near-basal lineages using a current molecular phylogeny, and compare their diversity with other areas of rain forest in Australia, and with other tropical areas in the Pacific. Twenty-eight dicot families below the eudicot clade may be regarded as near-basal; 16 of these are present in rain forest habitat in the Wet Tropics. The diversity of near-basal families, and of the species and endemics within these families, is similar in New Caledonia, and the family diversity similar to Costa Rica. We suggest that these data are consistent with other evidence that rain forest has persisted on the Australian continent for a long time, and that the role of Australian rain forests in harbouring a significant near-basal component has been underestimated. We also suggest that ongoing management might be focussed at conserving the evolutionary history present in the near-basal lineages, especially in the face of changing climatic patterns.