北京上方山种子植物区系的研究

ON THE FLORA OF SEED PLANTS IN SHANGFANG MOUNTAIN,BEIJING

北京上方山共有种子植物 81科 2 6 0属 4 0 4种 ,分别占北京市种子植物科、属、种数的6 8.6 % ,4 3.8% ,2 9.3% .其中种类最多的科是菊科 ,共有 4 6种 ,其他超过 10种的还有禾本科等 5科 .这 6个科共计有 170种 ,占该地区种子植物总种数的 4 2 .1% .2 6 0属种子植物分别属于 15个分布区类型 ,其中北温带分布占绝对优势 ,占总属数的 2 9.6 % ,其次是泛热带分布 ,占总属数的15 8% ,表明上方山地区的植物区系具有典型的北温带性质 .此外 ,上方山地区植物种的生活型以草本植物为主 ,并分布有一些特殊植物类群 ,反映出该地的植物区系在北京地区具一定特殊性 .

Based on data collection, information inquiry and field survey, The features and characteristics of the flora in Shangfang Mountain area are analyzed. The results show that there are 81 families, 260 genera and 404 species of spermophyta in the area. Those families, genera and species cover 68.6% of the families, 43.8% of the genera and 29.3% of the species of seed plants in Beijing region, respectively. The largest family of seed plants in the area is Compositae, which includes 46 species. Among the families with more than 10 species, besides Compositae, are, in turn, Legguminosae, Rosaceae, Liliaceae, Gramineae and Ranunculaceae. There are 173 species in the 6 families, accounting for 42.8% of the total number of the seed plants in Shangfang Mountain area. The 260 genera can be grouped into 15 distributional types as proposed by Wu Zhengyi. Of the 15 types, North Temperate type, making up 29.6% of genera, is on the top position, showing the flora a strong North Temperate distribution feature.