山西汾河源头地区种子植物区系地理成分分析

汾河源头地处山西吕梁山北段的管涔山系腹地,暖温带北部.据调查,汾河源头共有种子植物94科398属875种(含种下等级,下同),其中裸子植物3科7属12种,被子植物91科391属863种.种子植物科、属、种各类分布型占总数百分比没有明显的相关性,科、属、种的区系成分特有现象不平衡.科的分布区类型中,世界分布40科,温带分布30科,没有中国特有科；属的分布区类型中,温带分布264属,北温带成分处于显著地位,中国特有属4属,反映出该区植物区系的温带性质；种的分布区类型中,中国特有分布最多,共501种,其次是温带亚洲和东亚分布,成为构成汾河源头地区森林植被和灌从植被的建群种和优势种的主要成分.

Analysis of the Floristic Composition of Seed Plants in the Fenhe Source

The Fenhe Source is located in the hinterland of the Guancen Mountains of northern Luliang Mountain Range. This area belongs to the warm temperate zone and has the largest larch and spruce forest in North China. With great ecological function,the flora in the Fenhe Source is complex and diverse. In this study, 875 species of seed plants belonging to 398 genera and 94 families were found in the Fenhe Source. The gymnosperms included 12 species in 7 genera and 3 families,and angiosperms included 863 species in 391 genera and 91 families. Among these species ,four were National Key Protected Plants and 24 were Key Pro- tected Plants of Shanxi Province. The percentage of areal types of seed plants in families,genera,and species had no obvious relevance,and the endemic types were also unbalanced. In the areal types of family,Cosmopolitan, Pantropic, and Temperate types included 40 families, 19 families, and 30 families, respectively. However, no Endemic to China type was found. For areal types of genera,the temperate elements included 264 genera, in which North Temperate was the dominant type. Furthermore, Endemic to China type included 4 genera. The areal types of genera reflected temperate characteristics of the flora. In areal types of species, Endemic to China type included 501 species, which constituted the majority of the flora. The Temperate Asia and East Asia types included 236 and 97 species, respectively. These two types were the main constituents of constructive and dominant species of forest and shrubbery in Fenhe Source.