基于古DNA技术的科尔沁沙地全新世孢粉研究

The Horqin Sandy Land is one of the most serious desertification areas, which located in the transitional area of agriculture and herding of northern China with typical fragile ecological conditions. The climate and enviromental changes of the Horqin Sandy Land and the surrounding areas have always been the hot topics in the academic circles. It has a significant impact on the life of local population when the climate and environmental changed in the Holocene. It is a far-reaching significance to reconstruct the ancient vegetation for better understanding the relationship between the ancient population and the natural environment. In this project, we will analyse the pollens from the cultural and natural layers of the Holocene cemeteries in the Horqin Sandy Land and the surrounding areas using both the traditional methods including microscope and scanning electron microscopy (SEM), and the modern molecular biological method including ancient DNA, to show the vegetation distribution from both morphological characters and genetic diversities . Based on the relationship between the vegetation and the environment, the local climate and enviromental characters will be reconstructed.Combined with the archaeological information from the Holocene archaeological sites of the Horqin Sandy Land and the surrounding areas, the model of relationship between the ancient human population and enviromental changes will be discussed.Pollen analysis will reconstruct the Holocene climate and enviroment in the Horqin Sandy Land and the surrounding areas with multi-view and high resolution to reveal the dynamic changing regularity of ancient climate and desertification process. This study will provide scientific and valuble clues for preventing desertification, protecting plants, and rational use of the land resource.

科尔沁沙地位于中国北方的农牧交错带，是我国沙漠化最严重的地区之一,对其及周边地区气候及环境变化的研究一直是学术界关注的热点。全新世该地区气候及环境的变化对当地人群的生活产生了重要影响，对这一时期科尔沁沙地及周边地区多个遗址的文化层及自然地层的孢粉分析，可以复原古植被，重建古生态环境，对了解古代人群及自然环境的相互关系具有深远意义。本项目拟通过传统的孢粉分析方法包括显微镜及扫描电镜分析以及现代分子生物学方法的古DNA分析，从孢粉形态和遗传多样性两个方面复原科尔沁沙地全新世孢粉植物群；根据植物与环境的关系，探讨研究区全新世古生态及古气候特征；结合考古信息，探讨研究区全新世古代人群与气候环境变化的相互作用模式；此项研究将为揭示科尔沁沙地古环境及沙漠化进程的动态变化规律，正确认识沙漠形成及文化演化与气候环境的关系，有效控制沙漠化进程、保护植被、合理开发和利用土地资源提供重要科学线索。

科尔沁沙地位于中国北方的农牧交错带，是我国沙漠化最严重的地区之一，对其及周边地区气候及环境变化的研究一直是学术界关注的热点。本项目在传统的显微镜孢粉形态学分析方法的基础上，应用现代分子生物学方法的古DNA技术，从孢粉形态和遗传多样性两个方面复原科尔沁沙地全新世孢粉植物群。本项目首先应用原有的一代DNA测序技术对单粒孢粉进行DNA提取、扩增和测序，分析单一植物类群的遗传多态性。除此之外，本项目率先创新应用第二代DNA测序技术对湖泊沉积物样本进行宏基因测序及大数据分析，该新技术新方法在古植物孢粉学领域中的应用，提高了古植物鉴定的精确性。研究结果表明传统的形态学分析方法和古DNA方法各自有其优势，两个方法互补应用，可以更全面，准确地复原古植被情况，从而复原该研究区全新世古生态及古气候特征。该项目将为古植物研究提供新思路和新方法，也为揭示科尔沁沙地古环境及沙漠化进程的动态变化规律，正确认识沙漠形成及文化演化与气候环境的关系，有效控制沙漠化进程、保护植被、合理开发和利用土地资源提供重要科学线索，对我们了解古代人群及自然环境的相互关系具有深远意义。