晋北盐碱化草地群落斑块的多样性

Study of patches community diversity on salinization grassland in north of Shanxi province

通过对晋北盐碱化草地8个不同的草地群落斑块的优势度、多样性、群落相似系数及土壤性质等特征进行研究,揭示草地群落斑块在演替过程中的结构特征与变化规律,为进一步对草地植被恢复与盐碱化草地治理奠定理论基础。结果表明,8个群落斑块的物种组成和优势度差异比较明显,Margalef物种丰富度指数和Shannon-Wie-ner多样性指数在斑块Ⅱ、Ⅲ和Ⅰ、Ⅳ、Ⅴ、Ⅵ、Ⅶ、Ⅷ组之间差异极显著(P<0.01);Pielou均匀性系数和Simpson优势度指数在斑块Ⅱ、Ⅲ和Ⅵ、Ⅶ、Ⅷ之间差异极显著(P<0.01);斑块Ⅶ和Ⅷ、Ⅵ和Ⅶ、Ⅳ和Ⅴ群落相似系数最大,分别为0.956 7,0.929 7,0.903 4。8个群落斑块分为2类,其中斑块Ⅰ、Ⅱ、Ⅲ为一类,主要表现为土壤含水量、容重、pH值和碱化度比较小,植被特征主要是以较高大的赖草为优势物种,随着土壤的旱化,一些不耐旱的种群在群落中消退,比较耐旱的赖草在此类斑块中占据优势,形成以赖草为优势种的斑块;其他斑块为另一类,植被特征主要是以比较低矮的委陵菜和麻黄为主。

8 communities patches on salinization grassland were studied by the dominance,diversity and community characteristics.The purpose of this paper was reveal to the structure and variation of grassland community patches in the succession process,further provide the theoretical basis to grassland restoration and salinization grassland restoration.The results showed that the species composition and dominance of 8 community patches were more obvious different,the Margalef species richness index and Shannon-Wiener diversity index were significant different between the patchⅡ,Ⅲ and Ⅰ,Ⅳ,Ⅴ,Ⅵ,Ⅶ,Ⅷ（P0.01）,the Simpson dominance index and Pielou uniformity coefficient were significant different between the patches Ⅱ,Ⅲ and Ⅵ,Ⅶ,Ⅷ（P0.01）,the community similarity coefficients of the patch Ⅶ and Ⅷ,Ⅵ and Ⅶ,ⅣandⅤ were largest,respectively 0.956 7,0.929 7,0.903 4.There were two groups of community patches.Patch Ⅰ,Ⅱand Ⅲ were a groups,which soil moisture,bulk density,pH value and salinity were lower,the dominant plant is Leymus secalinus.With the drying of soil,some weak drought-resistant species disappeared from the community,while drought-resistant L.secalinus occupied dominant status in the group patches,there becomed community patches which dominant plant was L.secalinus.Others were in another group,the dominant plants were Potentilla anserina and Casuarina cunninghamiana.