古地中海退却与喜马拉雅—横断山的隆起在中国喜马拉雅成分及高山植物区纱的形成与发展上的意义

横断山－喜马拉雅植物区系的开端是在晚白垩纪和早古近纪（早第三纪）。古植物资料在古近纪初期横断山－喜马拉雅植物区系是同古地中海沿岸一致的以照叶林为主的暖湿植物区系。古近纪后期和新近纪（新第三纪）以后古地中海气候逐步旱化。原来的暖湿植物区系在地中海地区逐步消失，而在横断山及喜马拉雅和东亚其他地区得以保存和发展，现代横断山及东喜马拉雅的亚热带森林即是其后裔。古近纪中期以后由于古地中海的逐步退却，气候变得干旱，原暖湿植物区系逐步被现代旱生的地中海植物区系所取代。新近纪以后，旱生的现代地中海植物区系由于喜马拉雅和横断山的隆起而转向适应高山环境，逐步分化形成了现代的中国－喜马拉雅成分。横断山－喜马拉雅地区硬中高山栎林的起源；铁筷子属，绿绒蒿属，芒苞草属，假百合属及马桑属的地中海，喜马拉雅－横断山间断分布的形成便是古地中海植物区系残遗的体现；黄花木属，独一味属等众多中国喜马拉雅成分就是古地中海祖先的后裔。这些代表类群的分析研究表明现代的喜马拉雅－横断山的高山植物区系以及中国－喜马拉雅成分中有相当的一部分是起源于新生代旱生的地中海植物区系。

Tethys Retreat and Himalayas-Hengduanshan Mountains Uplift and Their Significance on the Origin and Development of the Sino-Himalayan Elements and Alpine Flora

The flora of Himalayas Hengduanshan Mountains started in late Cretaceous and early Paleogene.Paleobotanical data had showed that the flora of Himalayas Hengduanshan Mountains was a part of Tethyan Tertiary Flora or evergreen,laurophyll "paleotropical geoflora" in that time.After late Paleogene,along with climate of the Mediterranean gradually become aridity,the laurophyll "paleotropical geoflora" gradually replaced by semiarid or arid flora of the Mediterranean.The Tethyan Tertiary Flora was only conserved and developed in E Asian for monsoon climate bringing ample summer rain up to today.Therefore,most of subtropical evergreen broad leaved forest occurring in Himalayas Hengduanshan Mountains are the descendant of the Tethyan Tertiary Flora.After Neogene,the Himalayas Hengduanshan Mountains uplifted caused the semiarid or arid flora of Mediterranean turning to adapt to alpine environment and gradually differentiated and developed in these regions.Through analysis of the origin of sclerophyllus oaks forest in Himalayas Hengduanshan Mountain and the Euroasian disjunction in some examples: Helleborus,Meconopsis,Acanthochlamys,Notholirion and Coriaria ,as well as the descendants of Tethyan flora,such as Piptanthus,Lamiophlomis,Notochaete,Phyllopnyton ,exsiting in the regions,showed that quite a part of Sino himalayan elements and modern alpine plants of Himalayas Hengduanshan Mountains originated from the semiarid or arid flora of Mediterranean.