滇池盆地孢粉记录的29kaBP气候转型事件

A Pollen Record of Climatic Transition Event in Dianchi Basin at 29 kaBP

位于低纬度高原上的滇池盆地的气候主要受西南季风及东亚季风的控制,盆地沉积物是气候变化的敏感记录。通过对该盆地北部钻孔MIS3晚期孢粉记录的研究,发现在29kaBP该地区的气候明显发生了由暖干向凉湿的转型。29kaBP之前,孢粉组合中,乔木以喜暖的壳斗科、山核桃、鹅耳枥等为主,草本植物中较为耐旱的菊科、石竹科、禾本科等较发育,气候暖干;29 kaBP之后,孢粉组合改变较大,松属花粉含量增加突出,喜湿的铁杉和云杉少量出现,草本植物中莎草科增加,蕨类增多,气候较之前偏凉湿。通过对比发现,该气候转型事件具有区域对比性。

Dianchi Basin, located in the low latitude plateau of China and with its climate controlled by southwest monsoon and East Asia monsoon, is a sensitive region to the climate change. The paper mainly discusses the climate transition event at 29 kaBP. The pollen data at 29 kaBP of late MIS3 period obtained from the sediment core recovered from the north part of the basin, suggest obvious climate change from warm dry to cool. Before 29 kaBP, the spore-pollen assemblages mainly included species of trees, such as Quercus, Castanea, Carya and Capinus, and Herbs composed of Compositae, Gramineae, indicating a warm and wet climate. However, just after 29 kaBP, the warming type pollen declined, and Pinus, Tsuga, Picea, Cyperaceae increased, suggesting a climate change to cool and wet conditions.