新近纪是全球气候变化的重要时期，经历了从“温室气候”向“冰室气候”转换的关键期。本项目以滇西腾冲和梁河地区中新世晚期至上新世晚期不同层位植物化石为研究对象，进行古植被、古气候和古环境的综合研究。结合夹层火山岩同位素测年数据，确定含化石层位的准确地质时代。通过叶结构和角质层特征对化石叶片进行准确鉴定，并重建不同层位的植物群组合面貌特征；共存分析、叶缘分析以及气候-叶片多变量分析程序定量研究古气候变化规律；利用敏感植物类群的表皮气孔参数获取古大气CO2浓度的变化趋势。本项目是对申请人前期相关研究的深入拓展，并致力于揭示晚新近纪横断山西南侧的古植被和古气候演变规律。本项目对探索过去环境变化历史，预测未来环境发展趋势具有重要的科学价值。

The Neogene is a key time interval for the global climate switched from “greenhouse” to “icehouse” conditions. This project will carry out a comprehensive study of paleovegetation, paleoclimate and paleoenvironment based on plant fossils from the upper Miocene to the upper Pliocene in Tengchong and Lianghe regions, western Yunnan Province. According to the isotopic dating of the interbedded volcanics, the accurate geologic ages of the fossil-bearing horizons can be assigned. On the basis of leaf architectural and cuticular features, the fossil leaves will be identified precisely and then the plant compositions of each fossil horizon can be recovered. Using the methods of Coexistence Approach (CA), Leaf Margin Analysis (LMA), and Climate Leaf Analysis Multivariate Program (CLAMP), we will quantitatively reconstruct the paleoclimate changes at different horizons. Moreover, the paleoatmospheric CO2-levels will be studied by the stomatal analysis from some selected sensitive taxa. As a continuous research of previous studies on the late Miocene and late Pliocene floras of western Yunnan, this study will devote to reveal the paleovegetation and paleoclimate evolution during the late Neogene in the southwestern slope of the Hengduan Mountains. It will provide significant scientific values for exploring the environmental changes in the past and predicting the future environmental trends.