国家自然科学基金项目"石羊河尾闾(青土湖)水面形成的生态效应研究" (31160116), "人为干预下石羊河下游地下水动态变化及生态效应研究"(31260129), "民勤荒漠绿洲过渡带白刺灌丛沙堆表面风沙流特征与沙堆形成演变的关系研究"(41361001)
[目的] 分析青土湖输水过程对荒漠植物种多样性影响,为青土湖输水后的生态功能分析提供参考. [方法] 通过4 a的定位观测数据计算,分析青土湖岸植物种的多样性以及植物种的时间与空间变化及其与地下水位关系. [结果] 距水面200 m范围的植物种数量减少,其中距水面0 m的植物种减少最多,100 m处物种变化最少.Shannon-Weiner, Pielou指数和Simpson指数变化趋势相似,丰富度和多样性减小,均匀度和优势度增大;其中植物种优势度变化相对较大,且空间变化速率大于时间变化率,但Cody指数的时间变化率大于空间变化速率. [结论] 青土湖输水促使植物种及其多样性以水源为中心呈带状变化,形成特征植物圈,且随地下水位上升变化程度增大.
[Objective] The objective of this study is to investigate the influence of water delivery process on diversity of the plants in Qingtu Lake in order to provide basis for functional analysis in this region. [Methods] After a four year locating observation, biodiversity index was applied to analyze plant diversity in Qingtu Lake shores. The relationships between plant diversity variation and underground water level were also investigated. [Results] The number of plant species reduced within 200 m range from the water surface, and the maximum reduction occurred at the surface of water while the minimum reduction occurred at 100 m. Shannon-Weiner, Pielou index and Simpson index showed a similar trend, richness and Shannon-Weiner decreased, while Pielou index and Simpson index increased. Simpson index changed greatly, and the spatial variation was greater than the temporal variation. In contrast, the temporal variation of the Cody index was greater than the spatial variation. [Conclusion] Importing water to Qingtu Lake had prompted the spatial distribution of plant species. The water source is centre for the belt distribution of the plant species, and the change increase with the rise of the underground water level.