不同植物配置下人工湿地微生物群落特征及其影响因素

Characteristics of Soil Microbial Community and Their Imapact Factors in Different Constructed Wetlands with Plant Communities

植物是湿地生态系统的重要组分,本选择茭白(Zizania caduciflora)、鸢尾(Iris tectorum)、菖蒲(Acorus calamus)和芦苇(Phragmites australis),连续5年研究了不同植物配置下人工湿地微生物群落特征对环境的指示作用,结合微生物群落冗余分析(Redundancy analysis,RDA),研究了不同植物配置下人工湿地土壤环境因子及其对微生物群落分布的影响。结果表明:(1)土壤有机碳、全氮、全磷、全钾、速效磷和碱解氮呈一致的变化规律,均表现为芦苇>菖蒲>茭白>鸢尾,而不同人工湿地全磷差异不显著(p>0.05)。(2)人工湿地对土壤微生物量有较大的影响,土壤微生物量碳、氮、磷呈一致的变化规律,均表现为芦苇>菖蒲>茭白>鸢尾,不同人工湿地微生物量碳和氮差异均显著(p<0.05),微生物量磷差异不显著(p>0.05)。(3)物种丰富度指数(H)、均匀度指数(E)、和碳源利用丰富度指数(S)均表现为芦苇>菖蒲>茭白>鸢尾,而优势度指数(Ds)则表现为鸢尾>茭白>菖蒲>芦苇。其中不同人工湿地碳源利用丰富度指数(S)差异均显著(p<0.05),不同人工湿地优势度指数(Ds)差异均不显著(p>0.05)。(4)相关性分析表明不同人工湿地微生物物种丰富度指数(H)与SOC,TN呈显著正相关,芦苇和菖蒲的相关系数高于茭白和鸢尾,说明芦苇和菖蒲人工湿地微生物群落多样性高于茭白和鸢尾;RDA分析表明,土壤环境因子具有明显的生态梯度,SOC,TN是影响人工湿地微生物群落多样性的主要环境因子。

Hygrophytes are the important parts of a constructed wetland system.Four common wetland plants(Phragmites australis,Acorus calamus,Iris tectorum and Zizania caduciflora)in natural wetlands were chosen.The study compared the environmental indicator of soil microbial community in different constructed wetlands of plant communites by redundancy analysis during five years.The results showed that:(1)soil organic carbon,total nitrogen,total phosphorus,total potassium,available phosphorus and alkali-hydrolyzed nitrogen showed consistent change rules,which follow the sequence:Phragmites australis>Acorus calamus>Zizania caduciflora>Iris tectorum,but there was no significant difference in total phosphorus in different constructed wetlands;(2)constructed wetlands had great impact on soil microbial biomass,and the soil microbial biomass of carbon,nitrogen and phosphorus showed the consistent change rule,which follow the order:Phragmites australis>Acorus calamus>Zizania caduciflora>Iris tectorum;the differences of microbial biomass carbon and nitrogen of different constructed wetlands were significant(p<0.05),while the difference of of phosphorus microbial biomass was not significant(p>0.05);(3)species richness index(H),evenness index(E),and carbon source utilization richness index(S)decreased in the order:Phragmites australis>Acorus calamus>Iris tectorum>Zizania caduciflora,and dominance indexes(Ds)decreased in the order:Phragmites australis>Acorus calamus>Zizania caduciflora>Iris tectorum;the differences in carbon source utilization richness indexes(S)of different constructed wetlands were significant(p<0.05),while differences in Ds of different constructed wetlands were not significant(p>0.05);(4)correlation analysis indicated that the microbial species richness indexes of different constructed wetlands were significantly positively correlated with SOC and TN;The correlation coefficients of reed wetland and calamus wetland were higher than those of water shoot wetland and iris wetland,indicating that the microbial community diversities of constructed reed and calamus wetlands of were higher than those of water shoot and iris wetlands;RDA analysis showes that soil environmental factors have obvious ecological gradients,and SOC and TN are the main environmental factors affecting the microbial community diversities of constructed wetlands.