甘肃蕨类植物的地理分布及区系特点

The Phytogeographical Distribution and FloristicC haracteristics of Pteridophytes of Gansu Province

甘肃蕨类植物据初步调查和统计有34科,78属,292种,6变种、根据甘肃的地理和气候特点以及使蕨类植物的种类和分布状况,将甘肃蕨类植物划分为四个地理分布区:河西走廊厥类植物区、黄土高原蕨奂植物区、陇南山地蕨类植物区、甘南及祁连山高寒山地蕨类植物区.甘肃蕨类植物区系成分主要与西南、华东以至日本蕨类植物区系组成基本相同,都以鳞毛蕨科(Dryopteridaceae)、蹄盖蕨科(Athyriaceae)水龙骨科(Polypodiaceae)为主组成了甘肃蕨类植物区系的主要成分,并以耳蕨属(Polystichum).鳞毛蕨属(Dryopteris).蹄盖蕨属(Athyrium)为主要代表,还含有较多的热带和亚热带属.

Gansu Province is rich in Pteridophytes.Up to now,there are 34families,78 genera representing 292 epecies,6 varieties recognized.According to phytogeographical and climatical characteristics of Gansu aswell as species and disrributive conditions,PteridoPhytes in Gansu maybe diveded into 4 phyttogeographical distribution regions:the Pteridop-bytes region of Hexi Corridor,Pteridophytes region of the Loess plateau,Pteridophytes region of Lungnan mountains,Pteridophytes region of highmountains with cold climate of Gannan and Qilianshan.The geographical compositions of Pteridophvtes flora of Gansu arefundamentally simiar to those of Southwest China,East China and Japan,And all of tham are constituted with the Dryopteridaceae,Athyriaceaeand Polypodiaceae as the main parts of floristiceomposition.Furthermore,Polystichum,Dryopteris and Athyrium are Their cardnal representatives,and there are also more tropical and subtropical genara.