为探究半干旱区湿地—草原生态交错带的边界宽度及其群落多样性,于2014年7月对宁夏盐池县四儿滩湿地进行野外植被调查。利用移动分割窗技术对交错带进行定量判定,采用Shannon-Wiener指数、Simpson指数、Pielou均匀度指数、Margalef物种丰富度指数分析不同生境带以及不同样线间的植物群落多样性。结果表明:1)窗口宽度为6个样方时,能够清晰地划定此交错带的边界。东、西、南、北样线生态交错带的宽度分别为120,120,120,140m,距湿地核心区距离分别为180,220,240,200m。2)不同生境带Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef物种丰富度指数的排列顺序均为交错带>旱生带>湿生带,而 Simpson优势度指数的排列顺序为旱生带>交错带>湿生带。3)北样线的Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数均为最高值,而西样线4多样性指数均为最低值。研究结果可为干旱、半干旱地区湿地资源的保护、生物多样性的维持、生态系统的稳定提供理论支持和科学依据。

In order to study boundary definition and plant diversity of wetland-grassland ecotone in Yanchi country,Ningxia,vegetation investigation was carried out in July,2014.The moving split-window technique was applied to the quantitative determination of ecotone and diversity indexes(species diversity index,community dominant concentration index,community evenness index,species richness index)were used to analyze plant community diversity.The results showed:(1)When window width was 6 quadrats,it can clearly delineate the ecotone boundary;The ecotone boundary of east,west,south,north line transect is 120m,120m,120m,140m respectively and distance from core area of wetland is 180m,220m,240m,200m respectively;(2) species diversity index,community evenness index,species richness index of the four transect lines all followed the order of ectone>arid region>wet region,while community dominant concentration index was in such an order as arid region>ectone>wet region;(3)The species diversity index,community dominant concentration index,community evenness index of north line transect were higher,but four diversity indexes of west line transect were lower.The results can provide theoretical support and scientific basis for the protection of valuable wetland resources,the maintenance of biological diversity and the stability of ecological system in arid and semi-arid regions.