洞穴石笋生物标志物重建长江中游MIS11期古温度和古水文变化

洞穴石笋在古气候研究中发挥着重要的作用，最近已经从单支石笋中重建古水文并识别了暴雨事件，但从单支石笋中同时重建古温度和古水文信号还是一个难点问题。申请人在国际上提出了细菌3-羟基脂肪酸有记录温度和水文变化的潜力。本项目首先将采用优化的酸消解方法对豪猪子洞洞顶土壤、洞穴内表层沉积物和滴水中的3-羟基脂肪酸进行分析，完善3-羟基脂肪酸的温度和水文代用指标。然后将3-羟基脂肪酸的气候代用指标应用到豪猪子洞MIS11期的石笋中，重建长江中游MIS11期的古温度和古水文变化，查明该地区古温度和古水文关系，探讨气候变化的内在机理和驱动因素。本研究对气候变化内在机理的认知及对未来气候变化的预测具有一定的借鉴意义。

Stalagmites have become very important archives in paleoclimate reconstruction. Recently the reconstruction of paleohydrological changes and rainfall storms are possible from an individual stalagmite, however, the reconstruction of paleotemperature and paleohydrological signals from an individual stalagmite is infeasible. The applicant has recently proposed the potential of bacterial membrane derived 3-hydroxy fatty acids in recording the temperature and hydrological changes. In this proposal, we will firstly investigate the distributions of 3-hydroxy fatty acids in the cave overlying soils，cave surface sediments and drip water to further perfect the 3-hydroxy fatty acids based temperature and hydrological proxies. Then apply those proxies into Haozhu Cave stalagmites to reconstruct the paleotemperature and paleohydrological changes in the Yangtze River region during the MIS11, to investigate the relationship of paleotemperature and paleohydrological variations, and to discuss the mechanism and driven factors of climate change. This study can be taken as a reference for the study of past climate change and prediction of future climate.