Transformation of regional vegetation driven by climate change during the last deglacial–early Holocene at Chaohu Lake, eastern China: New pollen insights

Abstract

Reconstructing the vegetation history of east China during the last glacial–interglacial transition is crucial for understanding the East Asian Summer Monsoon (EASM) evolution. Here, we present a new high-resolution pollen record from Chaohu Lake to determine the detailed process of regional lowland vegetation succession and its response to the EASM changes during the last glacial–Holocene transition (13.9–9.1 cal ka BP) in the lower Yangtze Valley, eastern China. During the Older Dryas (OD, 13.9–13.5 cal ka BP) period, regional forest-steppe indicative of co–dominance of Artemisia, Poaceae, and deciduous Quercus was present under a cool and dry climate. During the Allerød Interstadial (AI, 13.5–12.9 cal ka BP), significant arboreal expansions of deciduous Quercus, Hydrangea type and evergreen Quercus occurred, while herbs retreated significantly, presumably driven by the relatively warm, humid climate. Forest-steppe readvanced during the Younger Dryas (YD) interval, as indicated by increases in Poaceae and Artemisia, suggesting a cool and dry climate. During the early Holocene, extensive oak-pine forest flourished as regional vegetation, responding to pronounced climatic amelioration.

Our pollen-based climatic record is closely correlated with stalagmites δ¹⁸O records from EASM region and Greenland ice cores δ¹⁸O records, indicating the teleconnection between EASM variation and North Atlantic climate during the last deglacial–early Holocene. However, our record indicates an intensified EASM during the early AI and a prolonged onset excursion during the YD, diverging from North Atlantic climate but closely correlated to sea surface temperature (SST) variations in the western tropical Pacific.