黄土高原地区种子植物区系特征

黄土高原在中国植物区系分区上属于泛北极植物区 ,中国 -日本森林植物亚区的华北地区黄土高原植物亚地区 ,是东西、南北旱生、中生和水生植物交汇和聚集区域。计有种子植物 1 47科 864属 32 2 4种 ,其中裸子植物 7科 1 3属 41种 ,被子植物 1 40科 85 1属 31 83种 ,具有中国特有属32个 ,黄土高原地区特有属 4个 ,特有种 1 64个。黄土高原地区种子植物区系的基本特征为 :植物种类相对丰富 ,在全国植物区系上占有重要地位 ;植物区系起源古老 ,原始类群丰富 ;地理成分复杂多样 ,以温带成分占优势 ;与周边地区区系的联系广泛 ,是多种成分汇集和过渡的地区 ;特有性程度相对低 ,稀有濒危植物丰富

THE CHARACTERISTICS OF THE SEED PLANT FLORA IN LOESS PLATEAU

The flora of loess plateau belongs to a Subregion in the North China Region in the Japan-China Forest Plant Subkingdom in the Holarctic Kingdom in Chinese flora, which is the crisscrossing and assembling place of xerophyte, mesophyte and hygrophyte from south to north and from east to west. There are 3224 species (including infraspecific taxa) of the seed plants (belonging to 864 genera, 147 families) in loess plateau. Among them, 41 species (belonging to 13 genera and 7 families) are of gymnosperm and 3183 species (belonging to 851 genera, 140 families) of angiosperm. In addition, 32 genera in loess plateau are endemic to China, and 164 species are endemic to loess plateau. Based on the analysis of the flora, the paper has discussed the major characteristics of the flora. It is comparatively rich in species, ancient in origin, complex, varied in geographical elements, and dominant in the temperate. The seed plant flora of loess plateau has widely related to other neighbor flora. Therefore, the flora is characteristics by the crisscrossing and assembling of diversified geographical elements. Compared with other area, the seed plant flora is less dominant in endemism,but more abundant in rare and endangered species.