Early to mid-Holocene vegetation history, regional climate variability and human activity of the Ningshao Coastal Plain, eastern China: New evidence from pollen, freshwater algae and dinoflagellate cysts

Abstract

Palynological evidence of an Early-Mid Holocene around the Hemudu archaeological site have not been insufficiently discovered. Two sediment cores HMD1501 and HMD1502, respectively, from the Tianluoshan site, Zhejiang Province, eastern China, were examined in this study on certain palynological aspects, i.e. pollen, spores, freshwater algae and dinoflagellate cysts. The results show the information relating climate change, vegetation history and human activity over the Early-Middle Holocene. In the early Holocene, ca. 10 708–7193 cal yr BP, abundant arboreal pollen Pinus and Quercus (evergreen) and small amounts of herb pollen and fern spores were observed in this study, then it was considered that conifer mixed forest with broad-leaf trees flourished in the Tianluoshan site and the adjacent areas under consistent warm and humid climatic conditions that was in line with the Holocene Climate Optimum. And afterwards, an increase in the herb pollen component and temperate broad-leaf taxa, combining a decrease in the tropical and subtropical taxa suggested that relatively cold and dry climatic conditions occurred during the mid-Holocene (ca. 7193–5655 cal yr BP), in particular, a large amounts of cultivated Poaceae (Oryza comp.) pollen grains ≥40 μm, in addition to rice relics from the Hemudu Cultural Stage, supports the presence of extensive rice agriculture on the Ningshao Coastal Plain, eastern China, during the mid-Holocene (ca. 7193–5655 cal yr BP). Moreover, four sedimentary facies marine sub-tidal, shallow-marine, shore lacustrine environments and plow layer in the two sediment cores were also identified.