Palaeoecological studies at four archaeological sites in the New Guinea Highlands document local vegetation histories and plant use from c. 18,000 cal BP to the recent past

Plant microfossils at archaeological sites in the New Guinea Highlands have received little attention compared to lithic and faunal analyses. Here we analyse plant microfossils (pollen, charcoal particles, phytoliths, and starch) from three rockshelters (Yuku, Kiowa, and Manim) and one open site (Wañelek), dating from c. 18,000 cal BP. Pollen results show a diverse range of taxa, and record major as well as subtle changes in vegetation history, with complimentary phytolith results. Vegetation changes, especially Nothofagus spp. decline, were driven by post-LGM climatic warming and anthropogenic deforestation, respectively, yielding mixed Castanopsis-Lithocarpus lower montane forest, and secondary forest, disturbance taxa, and grasslands. Low charcoal counts and ground fern establishment suggest periods of limited use within some rockshelters. Subsistence plant remains include starch of cf. Castanopsis acuminatissima nuts and cf. Colocasia esculenta corms, and a leaf phytolith of Musa sp. A new type of aquatic archaeological marker, cf. euglenoid cysts, was also identified.