横断山地处青藏高原东南缘，为全球植物多样性热点地区之一，其现代植物的物种多样性及分布格局极大地受到了该地区地史时期发生的剧烈地质、气候等环境变迁，因而是研究植物多样性形成与演化的理想地域。然而，以往研究主要集中于被子植物多样性的形成与演化，而裸子植物在该地区的多样性演化知之尚少。最近，申请人在地处横断山腹地的南班榜、福东和庆福3个晚上新世植物群中采集了一批保存完好、大部分具有三维立体结构的松柏类植物的球果、种鳞和叶片化石，是研究横断山松柏类甚至裸子植物物种多样性形成和演化的重要地史依据。本项目拟在前期材料采集的基础上，进一步补充研究材料，通过形态学、微形态学和解剖学等分类学研究手段，准确鉴定化石，从而揭示横断山晚上新世裸子植物的物种多样性，理解现在横断山裸子植物多样性的建立，并讨论其与新近纪该地区剧烈的地质、气候等环境变化的关联。

The Hengduan Mountains, located in the southeastern edge of the Qinghai-Tibetan Plateau, represents one of the plant diversity hotspots in China or even in the world. The modern diversity and distributional patterns of plants there are largely affected by the dramatic environmental changes during the geological past there. Hence, it is an ideal area for studying the evolution and formation of such modern plant diversity. However, previous interests have mainly been shown in angiosperms, whereas gymnosperms have rarely been investigated regarding the establishment of their modern diversity in the Hengduan Mountains. Recently, we found plenty of fossil cones, seed scales and small leaves of some conifers from three late Pliocene fossil floras namely Nanbanbang, Fudong and Qingfu within the Hengduan Mountains. These fossils are well-preserved, most of them being three-dimensional. Our preliminary identification demonstrates they may include several different taxa of conifers. Hence they are crucial evidence to answer the evolution and establishment of the coniferous or even gymnospermous diversity in the Hengduan Mountains. . In this project, we will collect more abundant fossil materials from the three fossil floras mentioned above, to cover almost all coniferous taxa the three floras may have. We then examined the fossils in morphology, surface micro-morphology and anatomy, in order to identify them correctly. Based on our credible taxonomy, we will present the gymnospermous diversity in the Hengduan Mountains during the late Pliocene. We will also interpret the diversity evolution of conifers in this region since the late Pliocene, and thus understand the formation of modern coniferous richness in the Hengduan Mountains. Finally, we will discuss the link between the late Pliocene coniferous diversity and dramatic environmental changes in the Hengduan Mountains.