title: Fungal communities respond to long-term CO2 elevation by community reassembly.
abstract: Fungal communities play a major role as decomposers in the Earth's ecosystems. Their community-level responses to elevated CO2 (eCO2), one of the major global change factors impacting ecosystems, are not well understood. Using 28S rRNA gene amplicon sequencing and co-occurrence ecological network approaches, we analyzed the response of soil fungal communities in the BioCON (biodiversity, CO2, and N deposition) experimental site in Minnesota, USA, in which a grassland ecosystem has been exposed to eCO2 for 12 years. Long-term eCO2 did not significantly change the overall fungal community structure and species richness, but significantly increased community evenness and diversity. The relative abundances of 119 operational taxonomic units (OTU; ∼27% of the total captured sequences) were changed significantly. Significantly changed OTU under eCO2 were associated with decreased overall relative abundance of Ascomycota, but increased relative abundance of Basidiomycota. Co-occurrence ecological network analysis indicated that eCO2 increased fungal community network complexity, as evidenced by higher intermodular and intramodular connectivity and shorter geodesic distance. In contrast, decreased connections for dominant fungal species were observed in the eCO2 network. Community reassembly of unrelated fungal species into highly connected dense modules was observed. Such changes in the co-occurrence network topology were significantly associated with altered soil and plant properties under eCO2, especially with increased plant biomass and NH4 (+) availability. This study provided novel insights into how eCO2 shapes soil fungal communities in grassland ecosystems.
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA.
authors.forename: Qichao
authors.initials: Q
authors.lastname: Tu
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA.
authors.forename: Mengting
authors.initials: M
authors.lastname: Yuan
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA.
authors.forename: Zhili
authors.initials: Z
authors.lastname: He
authors.affiliation: CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Xue
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA.
authors.forename: Liyou
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hobbie
authors.affiliation: Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Reich
authors.affiliation: Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, USA Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China jzhou@ou.edu.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
mesh_terms: D058448:Biota / Q000187:drug effects*; D002245:Carbon Dioxide / Q000378:metabolism*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005658:Fungi / Q000145:classification* / Q000187:drug effects* / Q000378:metabolism; D008910:Minnesota; D008969:Molecular Sequence Data; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012339:RNA, Ribosomal, 28S; D002245:Carbon Dioxide