神农架大九湖泥炭湿地甲烷通量特征及其与土壤微生物群落组成的关系

虽然神农架大九湖泥炭湿地的甲烷排放特征、土壤微生物群落组成已有一些研究，但是关于微生物群落与甲烷排放量的关系及影响的研究不多.采用涡度相关法和高通量测序技术，探讨2016年3月~2017年2月微生物对大九湖泥炭湿地CH₄通量排放的影响.结果表明，大九湖泥炭湿地研究期间表现为CH₄的源，年总排放量5 566.27 mg·m-2，日平均排放速率10.96 nmol·m-2·s-1；春、夏、秋、冬四季的平均通量分别为12.06、22.47、3.02、2.92 nmol·m-2·s-1；研究区优势菌为泉古菌（54.6%）、广古菌（18.9%）、酸杆菌（12.6%）等.对不同季节样品Shannon指数进行单因素分析，p值为0.000 127，分析结果表明:CH₄月通量变化均呈明显的倒“U”型；夏季CH₄通量最高，冬季最低；不同季节的微生物群落物种多样性存在显著差异；夏季、冬季微生物群落组成与CH₄通量分别呈显著正相关、显著负相关；未鉴别出的菌群和俭菌总门与CH₄通量呈极显著正相关关系，泉古菌门与CH₄通量呈极显著负相关关系. 

Methane Flux Characteristics and Its Relationship with Soil Microbial Community Composition of Dajiuhu Peatland in Shennongjia

Although the methane flux characteristics and the composition of soil microbial community in the Dajiuhu peatland in Shennongjia have been studied to some extent, there are few studies on the relationship and impact of microbial community and methane flux. Using eddy covariance method and high throughput sequencing technology, methane flux and structure of microorganism were investigated at the Dajiuhu peatland from March 2016 to February 2017. The results show that the Dajiuhu peatland was the source of CH₄ during the study period, with an annual total discharge of 5 566.27 mg·m-2 and a daily average emission rate of 10.96 nmol·m-2·s-1. The average fluxes of the four seasons were 12.06, 22.47, 3.02, 2.92 nmol·m-2·s-1, respectively. The dominant bacterium in the study area were Crenarchaecta (54.6%), Euryarchaeota (18.9%), and Acidobacteria (12.6%). Univariate analysis was performed on the Shannon index for different season samples with a p value of 0.000 127. The results showed that the change of the monthly methane emission flux during this year had clearly inverted " U" type curve, and CH₄ emission rate in summer was the highest which was the lowest in winter. There were significant differences in soil microbial composition between different seasons. There was a strong positive correlation between the microbial community composition and the methane emission flux during summer and a strong negative correlation during winter. Abundance of Parcubacteria showed a significant positive correlation with CH₄ flux, while abundance of Crenarchaecta showed a significant negative correlation with CH₄ flux.