中文摘要：

为了研究西北半干旱区湿地植被多样性差异,以宁夏盐池县四儿滩湿地为例,采用样线法,从湿地中央辐射向四个方向,布设东、南、西、北四条样线,共取样方88个,主要调查植被的盖度、高度、频度、株数等,计算每种植被的重要值,运用SPSS软件进行聚类,分析了该湿地的植被组成和群落特征。采用Shannon-Wiener指数、Simpson指数、群落均匀度指数和丰富度指数对植物多样性进行研究分析,并结合多年的气象数据,分析结果为：碱蓬和盐爪爪群落为湿生带的代表群落,白刺和沙鞭群落与芨芨草、猪毛蒿和苦豆子群落为交错带的代表群落,阿尔泰狗哇花、赖草和砂兰刺头群落为旱生带代表群落;四儿滩湿地四条样线之间植被多样性的差异主要受四儿滩湿地本身的地理环境和人类生产活动的影响。年际植被多样性差异主要受月降雨量分配的影响。

英文摘要：

In order to study plant diversity differences in a semi-arid region of northwestern China,taking Siertan Wetland,Yanchi County,Ningxia Hui Autonomous Region as example,using sample line approach,four line transects about east,south,west and north were set up in four directions from central wetland,88 sample plots were investigated in the four sample line,mainly investigated the frequency of occurrence,height,coverage,biomass etc,to calculate the important value of each vegetations.With the help of the SPSS13.0 software by using clustering analysis,we has analyzed this wetland vegetation composition and the community characteristics.Shannon-Wiener index,Simpson index,evenness index and richness index.and meteorological data of many years were used to analyze the plant diversity.The results were：（1）Suaeda glauca and Kalidium foliatum community is the representative in the wetland zone,Nitraria tangutorum and Psammochloa villosa community and Achnatherum splendens,Artemisia scoparia and Sophora alopecuroides community are the representatives in the ecotone.Heteropappus altaicus,Aneurolepidium dasystachys and Echinops gmelini community is the representative in arid-land zone.（2）The plant diversity differences among four line transects are mainly influenced by the wetland＇s environment and human activity.The plant diversity differences between years are mainly influenced by the rainfall of month.