三江源地区高寒草地群落特征研究

Community characteristics study on alpine grassland in source regions of three rivers

选择三江源区针茅草原和高山嵩草草甸6处典型样地为研究对象,采用样方调查法,分析了该地区高寒草地群落特征。结果表明:1)达日县和曲麻莱县高寒草甸物种丰富度较高,分别为20种和15种;兴海县、玛多县和唐古拉山乡草地物种丰富度较低,均为8种,杂多县物种数最低,仅有5种(P>0.05)。2)达日县和曲麻莱县物种多样性最高,分别为2.74和2.27;唐古拉山乡和杂多县最低,约为1.5;兴海县和玛多县针茅草原物种多样性均为1.87左右。唐古拉山乡和曲麻莱县均匀度指数稍低,分别为0.76和0.84,其余各县均匀度指数均较高。多样性指数与物种数极显著相关。3)聚类分析发现杂多县和曲麻莱县高山草甸首先被归为一类,接着将唐古拉山乡合为一类;然后依次是兴海县短花针茅草原和达日县高寒草甸,玛多县紫花针茅草原在最后被聚合为一类。

Typical Stipa Breriflova steppe in Xinghai, S. purpurea grassland in Maduo and alpine meadows in Dari, Zaduo, Qumalai and Tanggulashan counties were selected for studying the community character in source regions of three rivers with quadrats investigation. The results showed that 1） the richness of alpine meadow in Dari and Qumalai counties were higher, and there were 20 and 15 species （P〈0.05）. The species were 8 in Xinghai, Maduo and Tanggulashan, separately, but it was only 5 in Zaduo （P〉0.05）. 2） The diversity was the highest in Dari and Qumalai at 2.74 and 2.27. Moreover it was the lowest in Tanggulashan and Zaduo, and it was about 1. 5. The species diversity of Stipa steppe in Xinghai and Maduo both were 1.87. The Pielou index was lower in Tanggulashan and Qumalai at 0.76 and 0.84, then that were higher in other plots. The statistics showed that there was significant correlation between diversity and species（r= 0. 967, P〈0. 01）, the equation was y= 1. 130 1＋ 0.079 5x （R^2= 0. 935 9, P〈0.01）. 3） It was revealed that the alpine meadows of Zaduo and Qumalai were first classified into one group by clustering. Then alpine meadow of Tanggulashan was injected. After that the Stipa Breriflova steppe of Xinghai, alpine meadow of Dari were attributed to the group, and Stipa purpurea steppe in Maduo was clustered one group finally.