title: Bacterioplankton community responses to key environmental variables in plateau freshwater lake ecosystems: A structural equation modeling and change point analysis.
abstract: Elevated environmental pressures negatively affect the bacterial community structure. However, little knowledge about the nonlinear responses of spatially related environmental variable across multiple plateau lake ecosystems on bacterioplankton communities has been gathered. Here, we used 454 pyrosequencing of 16S rRNA genes to study the associations of bacterial communities in terms of environmental characteristics as well as the potentially ecological threshold-inducing shifts of the bacterial community structure along the key environmental variables based on hypothesized structural equation models and the SEGMENTED method in 21 plateau lakes. Our results showed that water transparency was the major driving force and that total nitrogen was more significant than total phosphorus in determining the taxon composition of the bacterioplankton community. Significant community threshold estimates for bacterioplankton were observed at 7.36 for pH and 25.6% for the percentage of the agricultural area, while the remarkable change point of the cyanobacteria community structure responding to pH was at 7.74. Furthermore, the findings indicated that increasing nutrient loads can induce a distinct shift in dominance from Proteobacteria to Cyanobacteria, as well as a sharp decrease and adjacent increase when crossing the change point for Actinobacteria and Bacteroidetes along the gradient of the agricultural area.
authors.affiliation: College of Environmental Science and Engineering, Peking University, Beijing, 100871, P, R, China; School of Environment and Energy, Peking University, Shenzhen, 518055, PR, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Jingqiu
authors.initials: J
authors.lastname: Liao
authors.affiliation: College of Environmental Science and Engineering, Peking University, Beijing, 100871, P, R, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Gao
authors.affiliation: College of Environmental Science and Engineering, Peking University, Beijing, 100871, P, R, China.
authors.forename: Dalin
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Sun
authors.affiliation: Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034P, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.affiliation: College of Environmental Science and Engineering, Peking University, Beijing, 100871, P, R, China. Electronic address: yhuang@pku.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Environment and Energy, Peking University, Shenzhen, 518055, PR, China.
authors.forename: Shengji
authors.initials: S
authors.lastname: Luan
mesh_terms: D001419:Bacteria / Q000145:classification*; D002681:China; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000382:microbiology*; D010933:Plankton / Q000145:classification*; D012336:RNA, Ribosomal, 16S; D014871:Water Microbiology; D060753:Water Quality
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Bacterioplankton; Change point; Cyanobacteria; Plateau lakes; Segmented; Structural equation model