宁夏盐池封育草地植被群落多样性及其与环境关系的典范对应分析

Diversity of Plant Community in Relation to Environment Factors Based on CCA in Fencing Region in Yanchi, Ningxia

为探究干旱区封育草地植被群落多样性以及影响植被群落分布的主要环境因子,结合国家荒漠化定位监测项目,于2014年7月对宁夏盐池封育草地进行植被调查。将研究区分为核心区(E)、边缘区(E1)、外围区(E2),采用样线与样方结合法调查植物名称、植物种类、株数、高度、盖度、生物量、土壤容重、土壤含水量、土壤紧实度、地表生物结皮盖度。在植被调查的同时,对每个样方中的土壤进行取样,分别测定土壤速N、速P、速K、土壤有机质含量。采用Shannon-Wiener指数、Simpson指数、Pielou均匀度指数测得植被群落多样性,运用典范对应分析方法(CCA)分析植被与环境因子的相关关系。结果表明,边缘区共出现了22种植物,主要物种有:黑沙蒿(Artemisia ordosica)、刺沙蓬(Salsola ruthenica)、地锦草(Euphorbia humifusa)、赖草(Leymus secalinus)、蒙古虫实(Corispermum mongolicum)。其SW、SP指数高于其他2个区域,数值分别为2.548、0.893,植被多样性最为丰富,群落稳定性最高。外围区共出现了16种植物,主要物种有:苦豆子(Sophora alopecuroides)、阿尔泰狗娃花(Heteropappus altaicus)、蒙古虫实其JSW指数最高,为0.842,植被多样性较丰富,群落稳定性较高。核心区出现了19种植物,猪毛蒿(Artemisia scoparia)、刺沙蓬、苦豆子,其SW、SP、JSW指数均小于其它2个区域,数值分别为2.163、0.828、0.734,植被多样性较差,群落稳定性较低。植被与环境的典范对应分析表明,土壤容重和结皮盖度是影响干旱区封育草地植被群落的主要环境因子。

To explore the diversity of plant community and the main environmental factors affecting the distribution in fencing region in arid area, combined with the national desertification monitoring and positioning project, vegetation investigation was carried out in July, 2014 in Yanchi, Ningxia. The studied area was divided into three areas:core area (E), edge area (E1) and peripheral area (E2). Samples of the plant population were recorded according to name, species, number, height, coverage, height, biomass, soil bulk density, soil moisture, soil compaction, the coverage of biological crust. Meantime, soil available N, fast P, fast K, the content of soil organic matter were respectively measured. They were analyzed in respect to diversity indices for community diversity (species diversity index, community dominant concentration index, community evenness index), and canonical correspondence analysis in order to analysis of the relationship between vegetation and environmental factors. The results showed 22 kinds of plants were found in edge area, the main species include: Artemisia ordosica, Salsola ruthenica, Euphorbia humifusa, Leymus secalinus, Corispermum mongolicum and SW (2.548), SP (0.893) index is higher than the other two areas. Its vegetation diversity is richest and the community stability is the highest. There are 16 kinds of plants were appeared in peripheral area, the main species include:Sophora alopecuroides, Heteropappus altaicus, Corispermum mongolicum and JSW index (0.842) is highest which means vegetation diversity rich and community high. There are 19 kinds of plants were found in core area, the main species include:Artemisia scoparia, Salsola ruthenica, Sophora alopecuroides. SW (2.163), SP (0.828), JSW (0.734) index is the lowest than the other two areas, its vegetation diversity is poor and community stability is low. Soil bulk density and soil crust coverage are the main environmental factors affecting plant community in fencing grassland in arid area based on CCA.