为了研究珠江三角洲滨海湿地土壤微生物群落多样性与养分的耦合关系,以2015—2018年珠江三角洲滨海红树林湿地、芦苇湿地、碱蓬湿地和互花米草湿地为对象,采用野外观测和室内分析相结合的方法研究了滨海湿地不同植物群落土壤微生物群落多样性和土壤养分含量。结果 表明:土壤pH值基本表现为,互花米草湿地>碱蓬滩湿地>芦苇湿地>红树林湿地,其中不同湿地植物群落土壤pH值差异均不显著(p>0.05); 土壤有机碳、全氮、全钾基本表现为互花米草湿地<碱蓬滩湿地<芦苇湿地<红树林湿地。滨海湿地不同植物群落土壤细菌数量占绝对优势,占微生物总数的70%左右。土壤微生物总数、真菌数目和放线菌数目均表现为互花米草湿地<碱蓬滩湿地<芦苇湿地<红树林湿地,其中不同湿地差异均显著(p<0.05)。土壤微生物量碳、氮、磷基本表现为互花米草湿地<碱蓬滩湿地<芦苇湿地<红树林湿地,其中微生物量碳、氮不同湿地差异均显著(p<0.05); 不同湿地微生物量磷差异均不显著(p>0.05)。土壤微生物群落的物种丰富度指数(H)、均匀度指数(E)、优势度指数(Ds)和碳源利用丰富度指数(S)基本表现为互花米草湿地<碱蓬滩湿地<芦苇湿地<红树林湿地,其中优势度指数(Ds)差异均不显著(p>0.05)。相关性分析显示,土壤养分和pH值与微生物群落功能多样性密切相关,其中pH值和土壤养分是滨海湿地不同植物群落土壤微生物群落多样性差异的重要影响因素。此外,土壤养分与微生物数量及微生物量关系密切,在生态保护和评估等研究过程中应充分考虑滨海湿地下的土壤微生物和养分的变化特征及耦合关系。
In order to study the variation of soil microbial community diversity and its influencing factors in coastal wetlands from 2015 to 2018, mangrove wetland, reed wetland, salicornia wetland and mutual flower rice grass wetland were selected to explore soil microbial community diversity and its influencing factors. The results showed that the basic pH value of soil decreased in the order: Spartina alterniflora wetland>Suaeda glaucawetland>Phragmites communis wetland>Rhizophora apiculata wetland, and there was no significant difference in soil pH value between different wetland plant communities (p>0.05); soil organic carbon, total nitrogen and total potassium increased in the order: Spartina alterniflora<Suaeda glauca wetland<Phragmites communis wetland<Rhizophora apiculata wetland; the number of soil bacteria in different plant communities in coastal wetlands was absolutely dominant, accounting for about 70% of the total number of microorganisms, followed by actinomycetes, with the least fungi; the total number of soil microorganisms, fungi and actinomycetes increased in the order, the wetland of Spartina alterniflora<Suaeda glauca wetland<Phragmites communis wetland<mangrove wetland, among which the difference among different wetlands was significant (p<0.05); the soil microbial biomass of carbon, nitrogen and phosphorus increased in the order, Spartina alterniflora<Suaeda glauca wetland<Phragmites communis wetland<Rhizophora apiculata wetland, among which soil microbial biomass of carbon and nitrogen was significantly different in different wetlands (p<0.05); the difference of microbial biomass phosphorus in different wetlands was not significant (p>0.05); the species richness index(H), evenness index(E), dominance index(Ds)and carbon source utilization richness index(S)of soil microbial community increased in the order, Spartina alterniflora<Suaeda glauca wetland<Phragmites communis wetland<Rhizophora apiculata wetland, among which the dominance index(Ds)was not significantly different (p>0.05). Correlation analysis showed that soil nutrients and pH value was closely related to the microbial community functional diversity, including negative contribution of pH value to soil microbial community functional diversity and positive contribution of soil nutrients to soil microbial community functional diversity, soil pH value and nutrients were the important influence factors on soil microbial community diversity in different plant communities of coastal wetlands. Soil nutrients were closely related to microbial quantity and microbial biomass, and their contents greatly affected microbial quantity and activity. In the process of ecological protection and evaluation, the change characteristics and coupling relationships of soil microorganisms and nutrients under coastal wetlands should be fully considered.
