四川裸子植物区系研究

四川裸子植物 9科 2 8属 1 0 1种 (含变种 ) ,区系成分为亚热带类型。东部地区古地理环境温和稳定 ,至今保存着许多珍稀孑遗的类群 ;西部地区古地理环境变化频繁 ,科、属少而种类丰富。东、西部差异明显。松柏类在这一地区十分突出 ,集中了从原始到进化的几乎各个类群的代表。四川裸子植物区系既不是泛北极区系迁移的产物 ,也不是热带区系的后裔 ,而是在二叠纪以来的地质历史发展过程中本地起源和发展起来的。

A floristic analysis on the gymnosperms of Sichuan

The flora of Sichuan has 101 species and subspecies in 28 genera of 9 families of gymnosperms. Many rare and endemic taxa are survived in its eastern part due to the fewer palaeogeographical changes in environment, meanwhile species richness is high with less genera and families in its western part as a result of the frequently palaeogeographical changes in environment. Coniferae in the Gymnospermae flora of Sichuan is very remarkable, including almost all the taxa from the primitive to advanced types. The Gymnospermae flora of Sichuan originated locally, neither descended from pan-arctic flora nor from tropical one, and had developed during the geographical history since Permian