多样性丰富的微生物对土壤生态系统的稳定起着主导作用,土地利用方式对其群落结构有着重要的影响.本研究主要采用454高通量测序技术探究森林变耕成茶园后,揭示土地利用方式改变对土壤微生物群落结构及其多样性的影响.结果表明:森林土壤变耕为茶园土壤后,Shannon、Simpson多样性指数以及菌群OTUs(Operational Taxonomic Unit,OTUs)都显著降低,表明茶园的耕种显著降低了土壤微生物的多样性.Metastats两两比较检验发现森林土壤和茶园土壤在8个门和44个属水平上有显著差异(P＜0.05).其中,森林土壤中Acidobacteria的丰度是茶园土壤的2倍,而Proteobacteria的相对丰度降低了10.59％.RDA冗余分析表明,土地利用方式改变后土壤的理化性质的变化是促使微生物群落结构改变的主要因素.从相关性因素看,pH 、NH3这2个环境因素与Chloroflexi、Acidobacteria这2门微生物群落的丰度呈现正相关性(P＜0.05),有机物、NO3-—N、总氮这3个环境因素与Proteobacteria、Actinobacteria、Planctomycetes、Firmicutes这4门微生物群落的丰度呈现正相关性(P＜0.05).对土壤中菌群PICRUSt代谢功能预测表明,森林变耕为茶园后土壤微生物的新陈代谢功能存在差异.因此,土地利用方式的改变对土壤群落组成和代谢活性产生了显著的影响,茶园耕作降低了土壤微生物的种群和功能多样性.该研究进一步深入研究土壤利用方式的改变对微生物的影响,为酸性土壤质量的演变机制和土地资源的合理开发利用提供科学依据.%The diversified microorganisms have played a dominant role in maintaining stability of the soil ecosystems.On the other hand.the type of land-use also greatly affects the microbial community.In the study of forestry 's turning into tea orchard,454 high-throughput sequencing technique is employed to explore how the change of land use has impacted the soil microbial community and its diversity.The results reveal that the Shannon,Simpson diversity index and the OTUs(Operational Taxonomic Unit,OTUs) have decreased significantly in the soil.It is indicated that the cultivation of tea plants has reduced the diversity of soil microbes (P ＜ 0.05).A great difference is also found between 8 phylums and 44 genera (P ＜ 0.05).The sequences data shows that the relative abundance of Acidobacteria in forest soil is two times higher than that in tea orchard soil and the relative abundance of Proteobacteria has decreased by 10.59％.The RDA redundancy analysis indicates that changes in soil chemical properties after the change of land use are the main factors that lead to the change of microbial community structure.The environmental factors such as pH,NH3 are positively correlated with the abundance of chlorophlexi and Acidobacteria (P ＜0.05) while organic matter,NO3-—N and total nitrogen have a positive correlation with the abundance of Proteobacteria,Actinobacteria,Planctomycetes and Firmicutes (P ＜ 0.05).The PICRUSt prediction of the metabolic function reveals that there is a difference in the metabolic function of soil microbes after the tillage of tea orchard.To conclude,the change of land use has a significant effect on the soil community composition and metabolic activity,and the tea plants cultivation potentially reduces the microbial diversity and functional diversity of soil microbes.By a further study about the influence of land use change on microbes,a scientific basis is provided for the evolution mechanism of acid soil quality and the rational exploitation and utilization of land resources.
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