马边大风顶国家级自然保护区种子植物区系研究

马边大风顶国家级自然保护区位于四川省马边县境内。在野外考察及查阅文献的基础上，对保护区内种子植物区系进行了研究。结果显示：保护区内有种子植物120科，446属，1240种，其中裸子植物5科，11属，27种；被子植物115科，435属，1213种。保护区区系成分较复杂，古老区系成分和滇藏高原成分较多。种子植物科的分布区类型有11个，具有较强的热带性质，泛热带（热带广布，Pantropic）型34科，占总科数的40．96％，属的分布区类型有15个，以温带区系成分为主，共264属，占总数属的64．71％。相似性系数计算结果显示，其与美姑大风顶自然保护区种子植物区系亲缘关系十分密切，区系组成相当一致，应该属于同一古老区系演化而成。

Seed Plant Florae in Mabian Dafengding National Nature Reserve

Mabian Dafengding National Nature Reserve is located in the limits of Mabian County,Sichuan and on the basis of field investigations and literatures references; the seed plant florae are studied. It is shown that there 1 240 species,446 genera and 120 families of seed plants of which there are 27 species,11 genera and 5 families belonging to gymnosperms,and 1 213 species,435 genera and 115 families belonging to angiosperms. The reserve is composed of diverse floristic elements which mainly consist of ancient floristic elements and Yunnan-Tibet plateau elements. There are 34 families falling into the category of pantropic and making up 40.96%,and the genera have 15 areals mainly composed of tropic floristic elements,which involve 264 genera accounting 64.71% of the genus total. The similarity coefficients reveal that the floristic elements in the reserve are closely related to those in Meigu Dafengding Nature Reserve and the florae of the two reserves are very identical and thus they may have evolved from one same ancient flora.