Identification of cultivated Pandanus and Colocasia in pollen records and the implications for the study of early agriculture in New Guinea

Abstract

Pollen records from the island of New Guinea, spanning the last 60 000 years, show a vegetation system sensitive to global climate change and strongly influenced by anthropogenic activity. The evidence for anthropogenic activity in pollen diagrams has focused on indirect indicators such as forest clearance, burning and increases in arable weeds. Tracing individual cultivars has proven to be very difficult as the major cultivated plants, in this case dominated by root crops, have low pollen production, are insect-pollinated or are harvested before flowering occurs. The identification of some cultivars is further restricted by limited information on pollen morphology. The pollen morphology of selected species from two genera (Pandanus and Colocasia), known to include important cultivated species, have been studied. Five pollen taxa are recognised after examination by light microscopy and scanning electron microscopy. It is shown that these can be easily distinguished on the broad criteria of pollen class, grain size and size of echini. The taxonomic and dispersal characteristics of the pollen morphology of these taxa are discussed and the implications of improved identification of cultivated species in late Quaternary pollen records are considered. Show more