云贵高原湖泊现生孟氏螺蛳壳体稳定同位素与元素变化对环境响应研究

Lake organisms and their shells can play important roles in quantifying and reconstructingof the changes inclimate and environment at different time scales.Here we focus on the Margarya mansuyi Dautzenberg et H. Fischer and its shell from lakes of the Yunnan-Guizhou Plateau, and combine the field and incubation studies with meterological records and limnological surveys with. We will first quantify the relationship between shell geochemical signals (e.g. stable isotope, geochemical elements) and the limnological and climate characters of the ambient environmentr through the application of multivariable methods，using both field and experimental data. Then, we aim to construct the transfer function between shell geochemical concentrations of the Margarya mansuyi Dautzenberg et H. Fischer and environmental variables over spatial scales and this model will be verified through sediment records from Xingyun lake over a centennial time scale. We can therefore uncover the mechanism that drive the spatio-temporal changes in the geochemical signals of Margarya mansuyi shells and this can greatly help understand the pattern in the changes of climate and lake environment in the Yunnan-Guizhou Plateau..This study can potentially stimulate the application of shell geochemistry in reconstructing the past environment and improve the accuracy in quantifying long-term changes of lake environment. In addition, this research has important theoretical and practical significance in understanding the driving roles of local climate and environment changes at organismal level, as well as in incovering regional environmental patterns and its response to global change in the low-latitude plateau areas of southwestern China.

高原湖泊中生物及壳体分布广泛，对环境变化极为敏感，化石遗迹丰富，在研究和重塑气候环境变化序列上，具有不可替代的优势。本项目以云贵高原湖泊特有的螺蛳属孟氏螺蛳壳体为研究对象，结合研究区气象、水文观测资料和室内控制培养试验，通过测定壳体和宿生水体的地球化学元素、稳定同位素及相关指标，探讨孟氏螺蛳壳体与宿生水体各指标间内在联系，建立孟氏螺蛳壳体稳定同位素、化学元素与宿生水体间的定量关系，并通过星云湖钻孔数据对其进行验证和完善。在此基础上，研究并掌握孟氏螺蛳壳体对不同气候因子的响应机制。项目的完成可充实和丰富利用生物壳体地球化学特征来反演区域气候环境的相关研究，达到提高气候环境解译准确度的目的，为进一步探讨云贵高原古螺生长时期气候环境及单体爆发事件研究打下基础。此外，本研究对理解我们现在气候环境变化的规律和机制，尤其是我国西南低纬高原区域环境格局与变化及对全球变化的响应，具有重要理论与实际意义。

云南高原湖泊中生物对环境变化敏感，其壳体在重建气候环境变化上具有显著的优势。项目通过对滇中湖泊水化学特性、孟氏螺蛳壳体地球化学特性（稳定同位素、元素等）与沉积特征、区域气候变化的研究，利用孟氏螺蛳壳体与宿生水体间内在联系，建立了孟氏螺蛳壳体地球化学特性与宿生水体间的相互关系，研究了孟氏螺蛳壳体对不同气候因子的响应机制。同时，项目利用研究结果及其他环境代用指标重建了全新世以来滇中星云湖流域的环境变化及人类活动对湖泊流域的影响。研究结果对理解当今气候环境变化的规律和机制，特别是我国西南低纬高原区域环境变化及对全球变化的响应，具有一定的理论与现实意义。