秦岭2种林分土壤性质的季节性变化对细菌群落多样性和组成的影响

研究秦岭山区2种林分土壤性质的季节性变化对土壤细菌群落多样性和结构特征影响，为该区生态恢复及物质循环提供理论依据。以云杉林和红桦林土壤为对象，采用Illumina Miseq高通量测序技术初步探讨了这2种林分不同季节土壤细菌多样性（Chao1指数和Shannon指数）和群落组成，并采用相关分析和冗余分析（RDA）等方法，探讨了土壤性质，包括pH、土壤温度、土壤含水量（SWC）、土壤有机碳（SOC）、可溶性有机碳（EOC）、微生物生物量碳（MBC）和易氧化有机碳（DOC）对土壤细菌多样性和群落的影响。结果表明:1）2种林分土壤细菌Chao1指数和Shannon指数具有明显的季节性变化特征，夏季最高，冬季最低，春季和秋季居中。2）2种林分土壤中酸杆菌门、拟杆菌门和变形菌门为优势菌门，酸杆菌门相对丰度在秋季最大，冬季最低，而拟杆菌门相对丰度则相反，在冬季达到最大值，秋季最低。3）相关分析表明，细菌多样性与温度负相关，与土壤pH、SWC、SOC、EOC、DOC和MBC含量正相关。4）RDA分析结果表明，SWC是影响真菌群落组成季节性变化的主要因素，其次是EOC和SOC含量。这些研究结果表明，秦岭林区土壤细菌群落多样性及群落组成的季节性变化是土壤养分及土壤环境因素（温度和含水量）共同作用的结果。

Effects of Seasonal Changes of Soil Properties on Soil Bacterial Diversity and Community Structure of Two Forest Types in Qinling Mountains

Effects of seasonal changes of soil properties on soil bacterial diversity and community structure of two forest types in Qinling mountains were preliminarily studied to provide theoretical basis for ecological restoration and material circulation.Soils of Picea asperata and Betula albosinensis forests occurring in Qinling mountains were taken as research objects to investigate the seasonal changes of soil bacterialα-diversity(Chao1 and Shannon indices)and community structure by using Illumina Miseq high-throughput sequencing technology.The methods of correlation and redundancy analysis were used to investigate the influences of soil properties on soil diversity and community,such as soil pH,temperature(ST),water content(SWC),organic carbon(SOC),dissolved organic carbon(DOC),easily oxidized organic carbon(EOC),and microbial biomass carbon(MBC).The main results were as follows.1)Chao1 and Shannon indices of the bacteria in two soils presented explicit seasonal variations:highest in summer,lowest in winter,and in the middle level in spring and autumn.2)Phyla Acidobacteria,Bacteroidetes and Proteobacteria were dominant bacterial communities in the two soils.The abundance of Acidobacteria was the highest in autumn,and the lowest in winter,while Bacteroidetes presented the highest abundance in winter,and the lowest in autumn.3)Correlation analysis showed that soil bacterialα-diversity had significantly positive correlation with soil properties,such as pH,SWC,SOC,EOC,DOC,and MBC.4)Redundancy analysis(RDA)results demonstrated that SWC was the primary factor for the variation of bacterial communities,followed by EOC,and SOC.It was concluded that seasonal changes of bacterial diversity and community of the forest soils in Qinling Mountains were resulted from the interaction between soil nutrients and environmental factors(temperature and moisture).