title: The spatial factor, rather than elevated CO₂, controls the soil bacterial community in a temperate Forest Ecosystem.
abstract: The global atmospheric carbon dioxide (CO₂) concentration is expected to increase continuously over the next century. However, little is known about the responses of soil bacterial communities to elevated CO₂ in terrestrial ecosystems. This study aimed to partition the relative influences of CO₂, nitrogen (N), and the spatial factor (different sampling plots) on soil bacterial communities at the free-air CO₂ enrichment research site in Duke Forest, North Carolina, by two independent techniques: an entirely sequencing-based approach and denaturing gradient gel electrophoresis. Multivariate regression tree analysis demonstrated that the spatial factor could explain more than 70% of the variation in soil bacterial diversity and 20% of the variation in community structure, while CO₂ or N treatment explains less than 3% of the variation. For the effects of soil environmental heterogeneity, the diversity estimates were distinguished mainly by the total soil N and C/N ratio. Bacterial diversity estimates were positively correlated with total soil N and negatively correlated with C/N ratio. There was no correlation between the overall bacterial community structures and the soil properties investigated. This study contributes to the information about the effects of elevated CO₂ and soil fertility on soil bacterial communities and the environmental factors shaping the distribution patterns of bacterial community diversity and structure in temperate forest soils.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Evironmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ge
authors.forename: Chengrong
authors.initials: C
authors.lastname: Chen
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Xu
authors.forename: Ram
authors.initials: R
authors.lastname: Oren
authors.forename: Ji-Zheng
authors.initials: JZ
authors.lastname: He
mesh_terms: D001419:Bacteria / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D044822:Biodiversity; D002245:Carbon Dioxide / Q000378:metabolism*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D017753:Ecosystem; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D009657:North Carolina; D009691:Nucleic Acid Denaturation; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014197:Trees
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; D009584:Nitrogen