塔里木河下游植物群落的物种数量变化与生态系统动态研究

物种多样性是指物种及其集合体的生物学多样性。物种多样性研究的核心是物种的数量变化和物种的生物学多样性程度。本文根据野外采集的数据 ,运用Simpson指数、McIn tosh指数以及Margalef指数 ,对塔里木河下游英苏、阿布达勒、喀尔达依、阿拉干、依干不及麻等地区的物种多样性指数分别进行了计算 ,并根据计算得到的生物多样性指数探讨了干旱区退化生态系统的物种多样性以及在干旱区物种多样性与生态系统稳定性之间的关系。结果表明 ,塔里木河下游从英苏至依干不及麻 ,Simpson多样性指数的变化范围为 0 82～ 0 2 6 ,McIn tosh均匀度指数的变化范围为 0 6 0～ 0 1 8,Margalef丰富度指数的变化范围为 1 4 7～ 0 38,物种数的变化范围是 9～ 2。分析表明塔里木河下游生态系统退化十分严重 ,并据此讨论了塔里木河下游生态系统退化的特征、演替动态及稳定性

Species quantity change and ecosystem dynamics in the lower reaches of Tarim River

Species diversity is biological diversity of species and its aggregation.The core of species diversity research is quantity change and biological diversity degree.This paper used Simpson index,McIntosh index and Margalef index to calculate the species diversity index in Yingsu,Abudale,Kaerdayi,Alagan,and Yiganbujima with data collected from the field.The species diversity and relationship between species diversity and ecosystem stability were analyzed in the degradating ecosystem of arid region.The results showed that the ecosystem is deteriorating,with Simpson index changed from 0.82 to 0.26,McIntosh index changed from 0.60 to 0.18,Margalef index changed from 1.47 to 0.38 and the mount of species changed from 9 to 2.The degenerative character,succession dynamics and stability of ecosystem were discussed according to these data at lower reaches of Tarim River.Two features were obvions in the process of degradation at the lower reaches of Tarim River: a)Vegetation community lost its ecosystem functions;b) Water factor had dominant effect in the degradation process.