【摘要】 依据植物在各海拔带出现的频率和不同海拔带植物种的生活型 ,对祁连山区草地群落海拔 2 5 0 0～ 30 0 0m的物种α多样性变化特征进行了研究 .结果表明 ,随海拔升高 ,Shannon Wiener指数从 1 4 32上升到 1 832 ,Simpson指数的变化较为复杂 .海拔 2 70 1～ 2 80 0m带是物种多样性的一个重要转折点 ,是物种多样性较丰富的地带 .在祁连山草地群落中 ,有毒的与食性较差的物种在各海拔带所占比例均超过5 0 % ,生物量占到整个样地生物量的 6 0 %以上 ,物种多样性已呈现衰退 .更多还原

【Abstract】 According to the occurring frequency and life form of plant species at different altitude levels,this paper studied the changing characteristics of the species α diversity of pasture community at the altitude from 2 500 m to 3 000 m in Qilian Mountains.The results showed that with increasing altitude,the Shannon-Wiener species diversity index increased from 1.432 to 1.832,and the variety of Simpson index was very complicated.An altitude of 2 701～2 800 m was an important turning point for species diversity.In pasture community of Qilian Mountains,the percentage of the poisonous and the less edible species exceeded 50%,and their biomass was more than 60% of the total biomass of the community.The biodiversity showed a degraded trend.更多还原