The early Holocene ecology of hilly terrain reconstructed by plant remains from Ping'an Cave in northern China

Abstract

Against the background of climate change during the late Pleistocene and early Holocene, human society gradually transitioned from a hunting/foraging economy to an agricultural economy. The role of climate change in the development of millet-based agriculture, which originated in northern China, is of major scientific interest. Millet agriculture is thought to have originated in areas of hilly terrain, because most of the early millet agricultural sites in northern China occur in such areas. Hence, understanding the ecological background of hilly terrain during the early Holocene is important for understanding the climatic and ecological mechanisms associated with the origin of millet agriculture. In this study, we reconstructed the ecological background of Ping'an Cave, an early Neolithic site in the hilly area of Beijing, based on analyses of pollen, fungal spores, and plant macrofossils recovered from the cave sediments. At ~11,000 cal kyr BP, deciduous broadleaved forest-grassland developed in the hilly areas of northern China, where the climate was warm and relatively dry. Nut shells of Juglans and Celtis were found, associated with an increase in Quercus pollen, indicating the development of a wetter climate at ~8000 cal kyr BP. Open deciduous broadleaved forest–grassland was the main vegetation type in the hilly areas of northern China during the early Holocene. The geographical characteristics of these areas were favorable for prehistoric humans, providing ecological resources from both forest and grassland.