中国杜鹃花属植物地理分布型及其成因的探讨

Discuss on the Rhododendron geographical distribution types and their cause of formation in China

关键词:  杜鹃花属  地理分布型  组与亚组  中国

Key words:  Rhododendron  geographical distribution type  sect and subsect  China

摘要:

依据植物分类学和地理学研究成果，尤其是从中国东部到西端喜玛拉雅杜鹃花类群分布及其现代与历史环境变化和规律，在已有的3个亚属级分布型的基础上，尝试建立了由7组和49亚组构成的11个杜鹃花属组与亚组级分布型体系。研究结果表明，该分布型体系展示了我国杜鹃花属植物类群在我国东部到西端的4个基本地理单元的分布面貌，尤其是展示了以杜鹃花亚属和常绿杜鹃亚属为主的不同大小、不同性质与不同进化程度的亚组级单位在上述分布体系中的位置与数量分布，从而揭示了我国东西向地形阶地由低到高和新生代以来生物地史由较稳定区到巨变区延展变化对杜鹃花属类群分布格局带来的巨大影响。指出，我国杜鹃花属植物的组与亚组级中的大类群、较广布群、原始群和常绿杜鹃类群的分布区或集中分布区偏向狭义横断山及其以东；反之，小类群、狭域与特有群、进化类群和有鳞类群的分布区或分布重心偏向（狭义）横断山及其以西。川西山地、狭义横断山、喜玛拉雅山既是杜鹃花属植物的集中分布区，也是某些类群扩散、迁移的地理屏障，对我国现代杜鹃花分布区及其分布格局的形成具有重要影响；东西向的地理环境变化是我国杜鹃花植物属下类群及其分布型变化的主轴。

Abstract:

A distribution type system which involves the 7 sects and 49 subsects was established，according to the production of the botanical taxology and geography，especially the Rhododendron distribution and their change and rule of the modern and historical environment from the east of China to Himalayas，based on the distribution type of the 3 subgenus class . The results showed that the system brought forth the Rhododendron distribution status about the 4 basic units of geography from the east to the west of China，especially the position and number distribution of these sects and subsects of different size，character and evolution degree which belong to subgen.Rhododendron and subgen.Hymenanthes and showed the profound effect to the Rhododendron distribution pattern from the east to the west where the topography was from lower to higher and the change of the biologic geology history was from the steadier state to the un steadiest state. It was seen that the distribution area or the mass distribution area，the sects and subsects were the larger，wider，more original and to belong to subgen.Hymenanthes，leaning to the Mt.Narrow Hengduans or their east area，which were the smaller，narrower and endemic，younger and to belong to subgen.Rhododendron，lean to the Mt.(Narrow)Hengduans and their west. At the same time，the mass distribution area of Rhododendron was the barrier to disturb the pervasion and transfer for some taxa in the west Sichuan Mountains，Mt.Narrow Hengduans and Mt.Himalayas where are important in the modern Rhododendron distribution area and pattern of formation in China. It would be a principal axis for the change of the groups and its distribution types under Rhododendron in China that the geographic environment changes from the east to the west.