摘要
【目的】探讨桂西北喀斯特山地草地土壤微生物群落对土壤养分的指示作用。【方法】采用经典统计分析与排序分析,连续3年研究了桂西北喀斯特山地草地土壤微生物群落多样性变化特征,并探讨了其与土壤养分和土壤微生物数量之间的关系。【结果】①桂西北喀斯特山地草地土壤pH变化范围为7.01~7.87,随着土层深度的增加逐渐增加,土壤养分随着土层深度的增加逐渐降低,具有明显的"表聚性",不同土层土壤全磷差异均不显著(P>0.05)。②土壤微生物以细菌数目最多,占到90%以上,土壤细菌、真菌、放线菌数目随着土层深度的增加逐渐降低。③根据培养第100小时的AWCD值计算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)。物种丰富度指数、均匀度指数、碳源利用丰富度指数均随着土层深度的增加而降低,不同土层碳源利用丰富度指数差异均显著(P<0.05);优势度指数随着土层深度的增加而增加,不同土层优势度指数差异均不显著(P>0.05)。④相关性分析表明土壤养分、土壤微生物数量均与土壤微生物群落多样性具有显著的相关性,其中,土壤微生物数量对微生物群落多样性的贡献最大(其相关系数绝对值最大)。⑤冗余分析表明土壤微生物群落多样性与土壤养分含量均呈正相关(除了pH);沿着RDA的第1排序轴,随着显著性影响因子(土壤养分各指标)的增加,微生物丰富度指数逐渐增加。【结论】微生物丰富度指数与pH值呈负相关;其中全碳和全氮与丰富度指数相关性最大,全碳和全氮是影响该区土壤微生物群落多样性分布的主要因子。
【Objective】The study aimed to explore the indicative function of soil microbial community on soil nutrients in Karst mountain grassland.【Method】We presented a comprehensive analysis of soil nutrients and microbial community in Karst mountain grassland from 2015 to 2017.Based on the soil microbial community and soil nutrients,the relationship between soil microbial community and soil nutrients has been studied by correlation analysis and redundancy analysis.【Result】The results showed that:(i)Soil pH varied from 7.01 to 7.87;Soil nutrients gradually decreased with the increase of soil depth,showing obvious‘surface polymerization’,while there was no significant difference in total phosphorus in different soil layers(P>0.05).(ii)The number of soil bacteria was the largest,accounting for more than 90%.The number of soil bacteria,fungi and actinomycetes gradually decreased with the increase of soil depth.(iii)The species richness index(H),evenness index(E),dominance index(Ds)and carbon source utilization richness index(S)of soil microbial community were calculated based on AWCD value at the 100 th hour of culture.The results showed that the species richness index,evenness index and carbon source utilization richness index all decreased with the increase of soil depth,and the differences of carbon source utilization richness index in different soil layers were significant(P<0.05).The dominance index increased with the increase of soil depth,and there was no significant difference in the dominance index of different soil layers(P>0.05).(iv)Correlation analysis showed that soil nutrients and soil microbial quantity were significantly correlated with soil microbial community diversity,and soil microbial quantity contributed the most to microbial community diversity(the absolute value of its correlation coefficient was the largest).(v)Redundancy analysis showed that there was a positive correlation between soil microbial community diversity and soil nutrient content(except pH).Along the first sequencing axis of RDA,with the increase of significant influencing factors(soil nutrients),the microbial richness index gradually increased,and the microbial richness index was negatively correlated with pH.【Conclusion】Total carbon and total nitrogen are the most correlated with richness index.Therefore,total carbon and total nitrogen are the main factors influencing the diversity distribution of soil microbial communities in this region.
作者
金章利
刘高鹏
周明涛
许文年
JIN Zhang-li;LIU Gao-peng;ZHOU Ming-tao;XU Wen-nian(Hubei Three Gorges Polytechnic,Hubei Yichang 443000,China;Hubei Jinyuanlvtong Ecological Environment Project Ltd.,Hubei Yichang 443000,China;College of Civil Engineering and Architecture,China Three Gorges University,Hubei Yichang 443002,China)
出处
《西南农业学报》
CSCD
北大核心
2019年第11期2638-2645,共8页
Southwest China Journal of Agricultural Sciences
基金
国家自然科学基金面上项目(51678348)
湖北省自然科学基金重点项目(2016CFA085)
国家重点研发计划项目(2017YFC0504902)
宜昌市应用基础研究项目(A18-302-b04)
关键词
喀斯特山地
土壤养分
微生物多样性
Karst mountain grassland
Soil nutrients
Soil microbial community
