澜沧江(西藏段)流域种子植物区系研究

A study on the flora of seed plants in Lancang River(in Tibet)

经调查统计得出澜沧江(西藏段)流域共有种子植物68科204属396种(包含变种和亚种).其中裸子植物4科7属14种,被子植物64科197属382属;种子植物区系组成中较大科(含20~35种)和中型科(含10~19种)共计有10科89属230种,分别占流域内种子植物科、属、种总数的14.71%,43.63%、58.08%,表明流域内的较大科和中型科在流域植物区系组成中起关键的构建作用,而流域内大属(含10种以上属)占的比重不大,属、种在区系中数量变化基本保持一致;植物属的区系成分中北温带分布的属达到83属,占流域总属数的47.16%,在流域内的属中占有绝对的优势,为明显的北温带性质;中国特有分布属只有2属,占到流域总属数的1.14%,表明流域内植物属的特有性不高.

Based on investigation and statistics,the result showed: the seed plants resource in Lancang River(in Tibet) consist of 68 families,396 species belong to 204 genera(include varieties and subspecies).Among them,4 families,7 genera,14 species belong to gymnosperm,and 64 families,197 genera,382 species to angiosperm;In composition of seed flora,the larger families(include 20 to 35 species) and medium families(include 10 to 19 species) are sum to 10 families,230 species belong to 89 genera,which accounted for 1...