Vegetation, fire, and climate history during the last 18500 cal a BP in south-western Yunnan Province, China

High-resolution pollen and charcoal records from Qinghai Lake in south-western China are presented. The records reveal variations in vegetation, fire and climate history since 18500 cal a BP. The results show that seven significant vegetation changes are recorded, which are responses to climate changes and/or fire events. Frequent and intensive fires occurred during the periods 17900-15000, 13000-11500 and 4280-980 cal a BP, corresponding to relatively dry climatic conditions. Combined with the climatic record from Tiancai Lake, the regional climatic changes since 18500 cal a BP in western Yunnan Province are reconstructed. Namely, the Heinrich Event 1, the Bølling-Allerød warm period and the Younger Dryas event during the last deglaciation are ubiquitous in western Yunnan Province. The start of the Holocene is recorded at 11500 cal a BP. The Holocene climatic optimum occurred between 8450 and 4280 cal a BP. After 4280 cal a BP, the climate deteriorated, accompanied by evidence for human impact. Based on this study, we consider that vegetation and climatic changes since 18500 cal a BP in south-western Yunnan Province are primarily driven by September and average summer solar insolation, with some associated influence from regional sea-surface temperature and sea-level rise.