水位梯度对毛乌素沙地柳湾林群落特征影响

Influence of Groundwater Level on Community Characteristics of Liuwanlin Ecosystem in Mu Us Sandy Land

根据典型样地和样方调查资料,采用聚类分析法,对毛乌素沙地柳湾林群落类型、多样性及生物量变化特征进行研究。结果表明,随着水位梯度的降低,柳湾林群丛类型由乌柳+中国沙棘群丛向北沙柳群丛过渡;辛普森指数、香浓-威纳指数、物种丰富度、均匀度指数和生物量均呈明显下降的趋势,相关系数分别为0.837、0.784、0.617、0.615、0.710。这表明水位梯度是影响毛乌素沙地柳湾林生态系统生物多样性与生产力的主要因素之一。

Based on the field survey data of typical plots and quadrats, the thesis researched the change of community types, species diversity and biomass of Liuwanlin ecosystem in Mu Us Sandy Land with cluster a- nalysis method. Results indicate that as the groundwater level reduces, the community components of Li- uwanlin ecosystem transit from Salixmicrostachya ＋ Hippophae rhamnoides to Salix psammophila, and the Simpson index, Shannon-Wiener index, Margalef species abundance index, Pielou evenness index and biomass of community components of Liuwanlin ecosystem all present an obviously decreasing trend, and the correlation coefficients between the indices and the groundwater level are 0. 837, 0. 784, 0. 617, 0. 615, and 0. 710, respectively. So groundwater level is one of the important factors which influence species biodiversi- ty and productivity of the Liuwanlin ecosystem in the Mu Us Sandy Land.