甘肃省荒漠种子植物科的区系分析

Floristic analysis of desert spermatophyte families in Gansu Province

对甘肃省荒漠区种子植物进行了普查和分析,结果表明:甘肃省荒漠区分布有种子植物543种,隶属55科228属,主要分布于河西走廊;植物种类贫乏,部分植被表现出退化现象,为典型的温带荒漠植被;具有大科较少、小科较多的特点,优势现象十分明显,优势科10个(藜科、豆科、禾本科、菊科、十字花科、蓼科、石竹科、毛茛科、蒺藜科和柽柳科),表征科6个(麻黄科、柽柳科、胡颓子科、蒺藜科、藜科和蓼科);该区地理成分多样,包含6个分布类型,其中以世界广布成分为主,共23科,占总科、种数的41.82%和76.80%,其次为温带成分(包括热带至温带分布、亚热带至温带分布和温带分布),共有23科,占总科、种数的41.82%和19.53%,热带成分、热带至亚热带成分较少,共9科,占总科、种数的16.36%和3.67%;植物在生活型上以多年生草本、灌木为主,这些反映出植物的分布与当地气候相适应的特点。

The vegetation in Hexi Corridor of Gansu Province was typical temperate desert with 543 species desert spermatophyte from 228 genera,55 families.In some areas,the vegetation was under degradation.The dominant family phenomenon with the characteristics of a few big families and many small families was quite obvious.There were 10 dominant families,including Chenopodiaceae,Leguminosae,Gramineae,Compositae,Cruciferae,Polygonum,Caryophyllaceae,Ranunculaceae,Zygophyllaceae and Tamaricaceae.Meanwhile,there were 6 typical families,including Ephedraceae,Tamaricaceae,Elaeagnaceae,Zygophyllaceae,Chenopodiaceae and Polygonum.According to the geographical element of family,there were 6 areal types in this area.The world areal type was the most abundant（23 families）,which respectively occupied 41.82% and 76.80% of the total number of family and species in this area.The temperate species took the second place,including the tropical,subtropical and temperate species from 23 families and they respectively occupied 41.82% and 19.53% of the total number of family and genera in this area.Tropical and subtropical species were quite rare（only 9 families） and they respectively occupied 16.36% and 3.67% of the total number of family and genera in this area.The perennial herbaceous species and shrubs were the dominant in terms of plant life type,it could reflect the mutual adaptive characteristics between vegetation distribution and local climate.