Microfossils as indicators of aquatic ecosystem evolution and monsoon dynamics

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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.