【摘要】 在青藏高原进行了大范围的群落调查 ,研究高原的两种主要草地群落类型———高寒草甸和高寒草原的植物物种丰富度及其变化。结果表明 :(1)在 5 0个样地 2 5 0个 1m× 1m的样方中 ,共出现 2 6 7种植物 ,其中高寒草甸179种 ,高寒草原 135种。在高寒草甸 ,1m2 样方内物种数最多为 32种 ,最少的仅为 3种 ;在高寒草原 ,物种数最多为 18种 /m2 ,最少的仅为 2种 /m2 。 (2 )物种丰富度随经度和纬度的增加呈增加趋势 ;随海拔的上升呈减少趋势。对物种丰富度与环境因子之间进行逐步回归 ,发现物种丰富度与生长季降水和温暖指数呈显著正相关。 (3)物种丰富度与地上生物量呈显著正相关。更多还原

【Abstract】 Patterns of biodiversity along environmental gradients is one of the basic issues in biodiversity research. Furthermore, the relationship between species richness and aboveground biomass is one of the most controversial subjects in ecology. In this paper, we studied the patterns of species richness along environmental gradients and the relationship between species richness and aboveground biomass in two major ecosystem types on the Tibetan Plateau, alpine meadow and alpine steppe. The results are summarized as follows: (1) 267 species were recorded in 250 plots of 50 sites, 179 of which occurred in alpine meadows and 135 in alpine steppe. The number of species ranged from 3 to 32 in alpine meadow, while it ranged from 2 to 18 in alpine steppe. (2) Species richness increased with latitude and longitude, and decreased with altitude. A stepwise regression analysis of species richness and environmental factors showed that the species richness was significantly correlated with growing season precipitation and warmth index. (3) Species richness was positively correlated with aboveground biomass.更多还原