油松人工林土壤微生物对结构调整的响应研究

Dynamics of Soil Microbial Groups in Pinus tabulaeformis Plantation in Response to Stand Structure Adjustment

[目的]为评估结构调整对油松人工林生态系统的影响,探索土壤微生物群落结构动态对结构调整干扰的响应机制。[方法]利用高通量测序技术,对结构调整后山西省中条山油松人工林林下土壤微生物的类群组成及多样性进行探究,分析土壤微生物群落的组成结构、多样性及其与环境因素的相互关系。[结果]油松人工林结构调整能够降低土壤的pH值,土壤养分含量显著低于对照样地。土壤微生物的优势菌群未发生较大的变化,土壤的优势细菌类群是变形菌门、放线菌门、酸杆菌门,而优势真菌类群为子囊菌门、担子菌门和被孢菌门。结构调整后油松人工林土壤微生物的丰富度显著增加,多样性较对照样地略有增加,但差异不显著。对结构调整前后的油松人工林微生物类群与土壤理化性质进行RDA分析,pH、总氮、土壤有机质和速效氮是驱动土壤微生物类群变化的主要因子。[结论]结构调整后的油松人工林样地仍处于恢复期,微生物类群结构与未调整样地相比具有相似性,但调整后的土壤微生物类群更为丰富,变形菌门和担子菌门的增加使得土壤中固氮菌的比例提高,土壤微生物类群向有助于有机质分解的方向转换。

[Objective]We explore the response mechanism of soil microbial community structure dynam-ics to the interference of stand structure adjustment in order to evaluate the impact of management treat-ment on the ecosystem of Pinus tabulaeformis Plantation.[Methods]Based on Pinus tabulaeformis plant-ations in Zhongtiao Mountain,Shanxi Province,we explored the group composition and diversity of soil mi-croorganisms under the stand structure adjustment through the high-throughput sequencing technology to analyze the diversity、composition and structure of soil microbial community and its correlation with envir-onmental factors.[Results]The results showed that stand structure adjustment could reduce the pH value of soil and the content of soil nutrients.The dominant flora of soil microorganisms did not change signific-antly.Proteus,actinomycetes and Acidobacteria were the dominant bacterial groups in the soil of Pinus tabulaeformis plantation,while the dominant fungal groups were Ascomycetes,Basidiomycetes and Mor-tierella.The richness of soil microorganisms in Pinus tabulaeformis plantation increased significantly after adjustment,but the difference was not significant in diversity.RDA analysis showed that pH,total nitrogen,soil organic matter and available nitrogen were the main factors driving changes in soil microbial com-munity structure.[Conclusion]The treated Pinus tabulaeformis plantation is still in the disturbance recov-ery period.The microbial community structure is similar to that of the control treatment,but is more abund-ant in Pinus tabulaeformis plantation after stand structure adjustment,which improves the proportion of ni-trogen fixing bacteria in the soil.The increase in Proteobacteria and Basidiomycota leads to soil microor-ganisms shift towards organic matter decomposition.