洮河国家湿地公园主要植物群落多样性对土壤环境因子的响应

Response of main plant community diversity to soil environmental factors in Taohe national wetland park

内陆河湿地原生植被群落多样性对土壤环境因子的响应分析,有助于深入理解河岸带原生植物群落的生态适应策略。采用双向指示种分析(two-way indicator species analysis, TWINSPAN)和典范对应分析(canonical correspondence analysis, CCA)方法对研究区27个样方的原生植物群落进行分析,研究河岸带植物群落多样性与土壤因子之间的关系。结果表明:研究区主要原生植物有8种生活型,群落类型可分为女贞(Ligustrum lucidum)+野蔷薇(Rosa multiflora)群落、杠柳(Periploca sepium)群落、艾蒿(Artemisia argyi)+狗娃花(Heteropappus hispidus)群落、旋覆花(Inula japonica)+败酱(Patrinia scabiosaefolia)群落、沙棘(Hippophae rhamnoides)+小檗(Berberis thunbergii)群落和沙棘+红花岩黄耆(Hedysarum multijugum)群落6类。群落的Shannon-Wiener多样性指数(H′)整体呈下降趋势,Pielou均匀度指数(J)呈现增减交替的趋势,Simpson优势度指数(C)整体呈增加趋势,土壤粉粒含量与Simpson优势度指数(C)呈显著正相关关系(P<0.05),其他土壤因子与多样性指数无显著相关关系(P>0.05),表明土壤中粉粒含量是影响河流湿地原生植物群落分布和多样性的关键因子之一。内陆河流湿地土壤质地类型的差异性一定程度上决定河岸带湿地生态系统原生植物群落的种类组成和分布格局。

Analysis of the adaptability of the distribution and diversity of virginal vegetation in inland river wetland to soil environmental factors is helpful to understand the ecological adaptation strategies of the native plant communities in riparian zone. This study aims to examine the response of main plant community diversity to soil environmental factors in Taohe national wetland park. The two-way indicator species analysis(TWINSPAN) and the canonical correspondence analysis(CCA) methods were used to analyze the native plant communities of 27 quadrats in the study area. The study site was located in the national wetland park conservation areas in Lintao County, Gansu Province, China(35°05′27″—35°15′58″ N, 103°45′43″—103°50′55″ E). Firstly, in the riparian zone on both sides of the middle section of Taohe National Wetland Park, a flat area with relatively intact native vegetation(vegetation formed by nature but not affected by obvious human activities), less disturbance from human activities, and no obvious topographic fluctuation was selected in the direction of vertical river. Secondly, the 27 representative sample plots, including shrub and herb communities were selected. A 5 m+5 m shrub quadrat was set in each shrub plot. The height, density and coverage of all species in the quadrat were recorded in the survey of shrub community. In the investigation of herb community, 3 plots(1 m+1 m) were randomly selected from the thicket quadrats, and the height, coverage, density, frequency and life type of all plants in each quadrat were recorded in detail. The results showed that there were 8 life types of the main native plants in the study area, and the community types could be divided into 6 types. They were Ligustrum lucidum+Rosa multiflora community, Periploca sepium community, Artemisia argyi+Heteropappus hispidus community, Inula japonica+Patrinia scabiosaefolia community, Hippophae rhamnoides+Berberis thunbergii community, and Hedysarum multijugum community. Besides, Shannon Wiener diversity index(H′) showed a decreasing trend as a whole, while Simpson dominance index(C) displayed opposite changing trend, and Pielou evenness index(J) exhibited a trend of increase or decrease in alternate. Moreover, there was a significantly positive correlation(P<0.05) between the content of soil silt and C, and there was no significant correlation between other soil factors and the diversity index(P>0.05), indicated that the soil silt content of the soil was one of the key factors affecting the distribution and diversity of native plant communities in river wetland. The difference of soil texture type in inland river wetland determines the species composition and distribution pattern of native plant communities in riparian wetland ecosystem to some extent.