浅水底栖有孔虫的生物学特性、δ18O和Mg/Ca的温盐效应：野外调查与室内培养实验协同研究

Chinese coastal and offshore region is a transitional zone between the maximum continent and the maximum ocean of the earth. How to obtain quantitative linkers in the land-sea contrast of global change research has been hampered by lacking of effective and accurate equational metrics for the reconstruction of paleotemperature and paleosalinity. Our project will address the above hold backs and carry out a series of field samplings on live benthic foraminifera, which has been regarded as signal carriers, from intertidal to shallow sea sediments monthly or seasonally. The environmental variables including temperature and salinity will be measured in situ. The temperature and salinity sensitive species of the foraminifera will be discriminated and their biological characters will be measured. A preliminary field-based empirical relation between foraminiferal test (δ18O and Mg/Ca ) and natural conditions (temperature and salinity) will be formed. Referring to the field references, we will designate representative species and set up a series of culturing experiments under controlled temperature and salinity gradients in laboratory. Further, comprehensive effects of temperature and salinity on foraminiferal biological specifics (e.g. morphology, proloculus) will be detected based on the process and results of the culturing experiments. Being compared and calibrated by the field-based empirical relations, the culturing results will generate several quantitative transfer equations between the shallow water benthic foraminiferal test (δ18O and Mg/Ca) and environmental variables (temperature and salinity). Finally the culture-based transfer equations will be applied to field examination. In summary, this project is characterized by the synergetic collaborations of field investigation and laboratorial culturing. Effective and accurate transformation relationships between shallow water benthic foraminifera and environmental conditions (temperature and salinity) will be established quantitatively based on multiple parameters of foraminifera and its ontogenesis process and mechanism. Our results would provide an effective key to eliminate constrains on paleoenvironmental reconstruction study in the neritic zones of China.

中国近岸浅沿海是介于世界最大的大陆和最大的大洋间的过渡带，因缺少有效精准的古温度和古盐度定量指标，无法建立全球变化研究海陆对比的定量链接。本课题以浅水底栖有孔虫为信号载体，通过从潮间带到浅海，按不同季节进行活体采样，同步观测温盐等环境参数，甄别和优选底栖有孔虫温盐敏感种、观察其生物学特征，建立统计学意义上的壳体δ18O和Mg/Ca与温盐环境的经验关系，同时选定实验室培养属种和参比自然条件的温盐培养参数。基于培养过程和结果，系统研究有孔虫生物学特性（形态、初房等）的温盐效应，以此为参照系并比对和标度野外经验转换关系，建立精准的底栖有孔虫壳体δ18O和Mg/Ca与海水温盐环境的定量转换方程，并进行应用检验。上述研究以野外实测资料和室内培养协同研究为特色，从生物学、同位素和元素化学多参数，从机理和过程等多角度获取浅水底栖有孔虫与温盐环境的定量转换关系，寻找破解我国近岸浅海古环境重建难局的钥匙。

本项目在国家自然科学基金（编号：41476043）的支持下，通过对浅海底栖有孔虫的野外调查和室内培养研究，对有孔虫的生物学特征和壳体化学元素的温盐效应进行了详细的研究，在有孔虫基础生物学、生态特性、壳体同位素与环境关系等方面取得了多方面进展，取得了具有一定的国际影响的研究成果。具体成果如下：1) 分类学和生态分布研究方面: 共描述底栖有孔虫183种，建立了1个新属、8个新种、1个新组合和13个新纪录种。对于在外部形态极易混淆的相似种和疑难种类进行了分子生物学研究，并给出了一套适用于玻璃质壳类有孔虫的DNA保存和提取的优化方案。2) 生物学特性的温盐效应研究方面：揭示了浅水底栖有孔虫总体和活体的群落的季节变化，了解季节因素对现生底栖有孔虫的影响，建立了物种丰度、多样性、壳双态与温度和盐度的定量关系。3) 浅水底栖有孔虫的壳体化学指标研究：建立了基于野外和培养条件下浅水底栖有孔虫代表种壳体δ18O和Mg/Ca与海水温盐环境的定量转换方程，为古环境和全球变化研究提供精准有效的定量链接。4) 研究技术和方法的凝练与创新：在野外调查和室内培养的研究过程中，对实验方法进行了实践和验证，对研究工具进行了创新，对研究方法进行了标准化，产生了专著、标准和专利等研究成果。共发表文章13篇，含SCI论文8篇（其中4篇为JCR一区）；此外，出版国际专著1部，国家标准1部，国家发明专利2项。培养博士后1名，博士2名，硕士研究生6名等。