黄土高原子午岭种子植物区系特征研究

黄土高原子午岭位于黄土高原中部半湿润半干旱过渡带(107°30′~109°40′E,33°50′~36°50′N)。其在植被分区上隶属于泛北极植物区、中国-日本森林植物亚区的华北地区黄土高原植物亚地区。区内共有种子植物94科361属689种,分别占黄土高原区种子植物总数的63.95%、41.78%和21.37%。其中大科、大属在区系组成中起着非常重要的作用。该区种子植物属包含15个分布区类型及12个变型,其中北温带分布、旧世界温带分布、泛热带分布、东亚分布等成分占有重要地位。其种子植物区系的基本特征是:植物种类相对丰富;多种地理成分交汇、过渡特征明显;区系组成以华北成分为主体,温带成分占优势;沿纬度梯度地理成分差异显著,垂直分布带谱不明显;区系成分新老并存,特有化程度低。

Floristic characteristics of seed plants in Ziwuling of Loess Plateau

Ziwuling(1073010940E,33503650N ) is situated in the center part of Loess Plateau.the transitional zone between semi-humid and semi-dry climate,and its flora belongs to Loess Plateau subregion,North China region,Sino-Japan forest subkingdom,Holarctic kingdom.There are 689 species of seed plants belonging to 361 genera and 94 families,among which,big families and big genera play important roles.The Ziwuling's flora could be divided into 15 distribution types and 12 subtypes,among which,the North temperate,old world temperate,pantropic,and e-Asia are important types.The analysis of the Ziwuling's basic floristic characteristics of seed plants showed that the flora was comparatively rich in species,geographical elements were diversiform,transitional characters of geography were obvious,and temperate components were dominant.The northern flora was different from the southern one,but there was no evident distinction in the dangling flora.