石羊河中下游河岸地下水位与植被物种多样性变异及其关系

选择物种丰富度指数、Shannon-Weiner指数、均匀度指数和Simpson优势度指数，根据石羊河中下游8个调查样地的11个地下水位观测井和植物样地野外采集的数据，对石羊河中下游河岸带地下水位及物种多样性特征进行了分析。结果表明:石羊河中下游物种多样性与地下水埋深有显著的关联性，随着地下水埋深增大，石羊河中下游物种丰富度和多样性均表现出递减趋势，反映了水分是影响植被分布和生存的主要因素，地下水位的不断下降和土壤含水率降低是引起石羊河下游植被多样性变化的主导因子。

Relationship and Variation of Riparian Vegetation Species Diversity and Groundwater Table in Middle and Lower Reaches of Shiyang River

Species diversity in riparian groundwater characteristics were analyzed in middle and lower reaches of the Shiyang River by selecting the species richness index, Shannon-Weiner index, evenness index and Simpson dominance index, and according to the data covering 11 groundwater observation wells and plant samples of eight sampling plots in Shiyang River. The results showed that species diversity and ground water depth had a significant correlation with the groundwater depth increases, the species richness and diversity showed a decreasing trend in the middle and lower reaches of Shiyang River, reflecting moisture is the main factors impacting distribution and survival of vegetation, the declining water table and soil moisture content significantly loss were dominant factors causing changes in vegetation diversity of lower reaches of Shiyang River.