宁夏盐池南海子湿地交错带判定及植被稳定性分析

Definition of wetland-dry grassland ecotone and vegetation stability in the Nanhaizi wetland in Yanchi,Ningxia

为研究半干旱区盐碱湿地生态交错带及其植被群落多样性和稳定性,于2016年7月通过样方(1m×1m)调查法对哈巴湖自然保护区的南海子湿地进行了野外植被调查。首先通过游动分割窗技术将研究区定量划分为湿生带、交错带和旱生带3个不同生活环境地带(以下简称生境带),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样线不同生境带间的植物群落多样性,采用M.Godron稳定性测定方法分析不同生境带植物群落稳定性。结果表明,1)东、西样线窗口宽度为6个样方,南、北样线窗口宽度为8个样方时交错带的边界可以被清晰地划定;2)不同样线不同生境带Shannon-Wiener多样性指数、Pielou均匀度指数和Simpson优势度指数的排列顺序均为交错带>旱生带>湿生带,而Margalef物种丰富度指数的排列顺序为湿生带>旱生带>交错带;3)湿生带植物种数最少,以耐盐碱植物为主,植被群落最稳定,旱生带次之,交错带植被种数最多,群落最不稳定。

To determine vegetation community diversity and stability in different habitat regions of the Nanhaizi wetland in Yanchi County, Ningxia Autonomous Region, vegetation surveys were conducted in July 2016. Firstly, the moving split-window technique was applied to the quantitative determination of ecotone. According to the result, the research area was divided into wetland regions, ecotone, and arid regions. Then, diversity in- dexes （species diversity index, community dominant concentration index, community evenness index, and spe- cies richness index） were used to analyse plant community diversity of different habitat regions in different transect lines. The M.Godron stability determination method was used to analyse plant community stability in different habitats. The results showed： 1） The ecotone boundary could be clearly delineated with six quadrats of east and west transect lines, and eight quadrats of south and north transect lines. 2） Species diversity index, community evenness index, and community dominant concentration index of the four transect lines all followed the order of ecotone〉arid region〉wet region, whereas the species richness index was ordered as wet region〉arid region〉ecotone. 3） As compared to that ot the other two habitat regions, the ecotone had the highest sta-bility Of vegetation, but the least species. The M. Godron stability followed the order of wet region〉arid region〉ecotone. The research showed that the moving split-window technique could be used to quantitatively determine small-scale wetland-grassland ecotones.By analysing the data and making comparisons, we found a negative correlation between vegetation diversity and stability.