青藏高原全新世C3/C4植物演化与气候环境因子的耦合关系研究

青藏高原是气候变化研究的重点区域和理想“实验室”，现已成为全球地学工作者关注的焦点。然而，目前缺乏对青藏高原地区全新世C3/C4植物分布与演化的系统研究，以致影响了利用C3/C4植物演化反演古气候特征，从而限制了未来全球变暖背景下对C3/C4植物分布与演化的认识和预测。本研究拟以青藏高原典型湖泊沉积物为载体，在AMS14C和210Pb精细测年的基础上，通过分子生物标记物和单体碳、氢同位素组成的综合分析，开展青藏高原全新世气候变化和C3/C4植物演化的定量化研究，重建青藏高原全新世C3/C4植物的演化历史及其随温度和降水波动的定量变化幅度，厘清C3/C4植物对气候变化的响应机理，阐明全新世气候变化和C3/C4植物分布与演化的区域特征，进一步为预测未来全球平均增温1-2℃背景下青藏高原地区C3/C4植物生物量的定量变化幅度提供更为准确的科学依据和参考数据。

The Tibetan Plateau is a key area and an ideal “laboratory” for climate change research, which has become the focus of global geoscientists. However, there is a lack of systematic study on the distribution and evolution of C3/C4 plants in the Tibet Plateau since the Holocene. Therefore, the use of C3/C4 plant evolution to retrieve paleoclimate characteristics is affected, which limits the understanding and prediction of C3/C4 plant distribution and evolution under the global warming in the future. In this study, taking typical lake sediments of the Tibetan Plateau as the research object, the molecular biomarkers, compound-specific carbon and hydrogen isotope composition of lake sediments will be studied, combined with AMS 14C and 210Pb fine dating, quantitative study on climate change and evolution of C3/C4 plants in the Tibet Plateau since the Holocene was carried out, it is to reconstruct the evolutionary history of C3/C4 plants and their quantitative variation amplitude with temperature and precipitation fluctuations, to investigate the mechanism of C3/C4 plants responding to climate change, to clarify the regional characteristics of climate change and evolution of C3/C4 plants since the Holocene, which further provides more accurate scientific basis and reference data for predicting the quantitative variation range of C3/C4 plant biomass in Tibet plateau under the background of global average temperature increase of 1-2℃ in the future.