四儿滩地区植物种群的生态位

本研究运用Levins生态位宽度指数及Pianka生态位重叠指数，对宁夏盐池四儿滩湿地的植物生态位宽度及生态位重叠度进行了研究，深入了解湿地植被的特征，为半干旱区天然湿地的植被保护和生态恢复提供参考方法。结果表明，湿地周边不同样线的主要优势种各不相同，可见湿地生态系统中植物种群呈聚集分布的特点。四条样线中西、北两条样线的植被生长状况较好，而东、南样线的植被则相对较差。刺沙蓬(Salsola pestifer)、阿尔泰狗娃花(Heteropappus altaicus)、沙鞭(Psammochloa villosa)、苦豆子(Sophora alopecuroides)是四儿滩湿地的主要优势种，蒲公英(Herba taraxaci)、紫菀(Aster tataricus)、虎尾草(Lysimachia barystachys)、角蒿(Incarvillea sinensis)、香青兰(Dracocephalum moldavica)、沙葱(Allium mongolicum)、黑沙蒿(Artemisia ordosica)等是四儿滩湿地的特化种。四儿滩湿地的生态位重叠度统计结果显示，生态位宽度大的物种与其他物种的重叠度指数不一定大，生态位宽度和较高的生态位重叠度之间并不存在直接的线性关系，这一现象从另外一个角度说明了湿地生态系统资源环境存在高度的空间异质性。

Plant population niche in Siertan wetland

In order to understand the characteristics of wetland vegetation and provide a reference for ecological restoration and vegetation protection of natural wetlands in semiarid areas,we measured indexes of Levins niche width and Pianka niche overlapping to examine the niche width and niche overlapping of plants in Siertan wetland,Yanchi county,Ningxia.The results of this study showed that the dominant species were not identical in different sample lines surrounding wetland,and plant population in wetland ecosystem presented the pattern of concentrated distribution.Among the four sample lines,the plants in the west and north sample lines grow better than the plants in the east and south sample lines.Salsola pestifer,Heteropappus altaicus,Psammochloa villosa,and Sophora alopecuroides are the dominant species in Siertan wetland,Herba Taraxaci,Aster tataricus,Lysimachia barystachys,Incarvillea sinensis,Dracocephalum moldavica,Allium mongolicum,and Artemisia ordosica are associated species.The results of niche overlapping showed that the species with big niche width did not always have big niche overlapping,and the niche width and niche overlapping did not have an obvious linear relation.This result further supports the view that resources have high spatial heterogeneity in wetland ecosystem.