Microfossils as indicators of aquatic ecosystem evolution and monsoon dynamics

在第三个资助期(36个月)，我们建议(1)对青藏高原(TP)最近的介形虫进行实际-生态、分类和生物地理分析，(2)使用介形虫贝壳的物种组合、微量元素和稳定的同位素特征来检测过去约2a(2a)年至年代际分辨率的湖平面变化对季风动态、融化水供应、降水与蒸发比的变化以及温度的变化。从唐古拉湖系、太郎、南盆、玉树地区的一到两个湖泊，以及(2b)唐格拉-阴湖、太郎、黑海和星海的十年到百年分辨率，评估晚更新世和全新世的长期环境变化和短期事件。在TP的南部和北部战略性地选择湖泊位置，以便在空间和时间上探测单个季风气团的影响。对介形虫化石组合的环境解释将基于生态容忍度、偏好和传递函数，这些将(3)测试是否适用于末次冰期以前的介形虫组合。重点将是从介形虫壳中建立新的微量元素替代物和介形虫物种组合数据的量化。(4)反映特定季风气团区域印记的代理数据的湖间合成将与基于过去7ka统计缩减尺度的结果进行比较，以最终破译全新世季风动力学的驱动因素。

During the 3rd funding period (36 months) we propose to (1) perform coupled actualistic-ecological, taxonomic, and biogeographic analysis of Recent ostracodes from the Tibetan Plateau (TP), to (2) use species assemblages, trace elements and stable isotope signatures of ostracode shells to detect lake level changes in response to monsoon dynamics, melt water supply, variations in precipitation vs. evaporation ratios, and temperature at (2a) annual to decadal resolution for the past approx. 1000 years from the Tangra Yumco lake system, Taro Co, Npen Co, and one to two lakes of the Yushu region, as well as at (2b) decadal to centennial resolution from lakes Tangra Yum Co, Taro Co, Heihai, and Xingxinghai to assess long-term environmental changes and short-term events during the late Pleistocene and Holocene. Lake sites are strategically selected on the southern and northern TP in order to detect individual monsoonal air mass impact through space and time. The environmental interpretation of fossil ostracode assemblages will be based on ecological tolerances, preferences and transfer functions that will (3) be tested for applicability to pre-LGM ostracode assemblages. Emphasis will be given to the establishment of new trace element proxies from ostracode shells and the quantification of ostracode species assemblage data. An (4) inter-lake synthesis of proxy data reflecting the regional imprint of specific monsoonal air masses will be compared with results based on statistical downscaling for the last 7 ka to ultimately decipher drivers of Holocene monsoon dynamics.