新疆塔里木河下游物种多样性变化与地下水位的关系

根据塔里木河下游9个断面40眼地下水位观测井和8个植物样地野外采集的数据，运用物种多样性指数对塔里木河下游物种多样性与地下水位变化进行了分析计算。研究表明，塔里木河下游物种多样性与地下水位变化有着密切的关系，地下水位对物种多样性的变化起着主导作用。塔里木河下游浅层地下水位埋深较大，并且表现为由上游段至下游段逐渐加深这样一个明显的递减变化。塔里木河下游物种多样性指数较低，Shannon Weiner指数和Simpon指数分别变化在1.93~0.53之间和0.82~0.35之间；随着由上游段至下游段地下水位埋深的加大，塔里木河下游植物种类减少、群落结构简单、物种多样性指数和丰富度指数呈明显降低的态势。反映了干旱区水分胁迫对生态系统的强烈影响。

STUDY ON SPECIES DIVERSITY AND THE CHANGE OF GROUNDWATER LAVEL IN THE LOWES REACHES OF TARIM RIVER,XINJIANG,CHINA

In this paper, the species diversity and the change of groundwater level in the lower reaches of Tarim River are analyzed and calculated based on the field-collected data from 40 observation wells of groundwater level along 9 sections and 8 plant plots in the lower reaches of Tarim river. The study shows that the species diversity is closely related to the change of groundwater level in the lower reaches of Tarim river, and the groundwater level plays a dominant role in the species diversity. In the lower reaches of Tarim River, the shallow groundwater level is deep, and it becomes deeper gradually from the upper reaches to the lower reaches, i.e., there is an obvious increase in the depth of groundwater. The index of species diversity is small in the lower reaches of Tarim River, and the Shannon-Weiner index and Simpon index vary in ranges of 1.93~0.53 and 0.82~0.35 respectively. Along with the increase of groundwater depth from the upper reaches to the lower reaches of Tarim River, the plant species become less, the structure of plant communities becomes simpler, and the diversity index and abundance index of the species are in an obvious decrease status. All these reflect the serious impacts of moisture stress on the ecosystems in this arid area.