Seasonal and ecohydrological regulation of active microbial populations involved in DOC, CO2, and CH4 fluxes in temperate rainforest soil

Levy-Booth, David J. (Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, Canada ; Hakai Institute, Tula Foundation, Heriot Bay, Canada) ; Giesbrecht, Ian J. W. (Hakai Institute, Tula Foundation, Heriot Bay, Canada ; School of Resource and Environmental Management, Simon Fraser University, Burnaby, Canada) ; Kellogg, Colleen T. E. (Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, Canada ; Hakai Institute, Tula Foundation, Heriot Bay, Canada) ; Heger, Thierry J. (School of Viticulture and Enology, HES-SO // University of Applied Sciences Western Switzerland) ; D'Amore, David V. (U.S. Department of Agriculture, Forest Service, Pacific Nothwest Research Station, Juneau, Alaska, USA) ; Keeling, Patrick J. (Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada) ; Hallam, Steven J. (Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, Canada) ; Mohn, William W. (Department of Microbiology & Immunology, Life Sciences Institute, University of British Columbia, Vancouver, Canada)

The Pacific coastal temperate rainforest (PCTR) is a global hot-spot for carbon cycling and export. Yet the influence of microorganisms on carbon cycling processes in PCTR soil is poorly characterized. We developed and tested a conceptual model of seasonal microbial carbon cycling in PCTR soil through integration of geochemistry, micro-meteorology, and eukaryotic and prokaryotic ribosomal amplicon (rRNA) sequencing from 216 soil DNA and RNA libraries. Soil moisture and pH increased during the wet season, with significant correlation to net CO2 flux in peat bog and net CH4 flux in bog forest soil. Fungal succession in these sites was characterized by the apparent turnover of Archaeorhizomycetes phylotypes accounting for 41% of ITS libraries. Anaerobic prokaryotes, including Syntrophobacteraceae and Methanomicrobia increased in rRNA libraries during the wet season. Putatively active populations of these phylotypes and their biogeochemical marker genes for sulfate and CH4 cycling, respectively, were positively correlated following rRNA and metatranscriptomic network analysis. The latter phylotype was positively correlated to CH4 fluxes (r = 0.46, p < 0.0001). Phylotype functional assignments were supported by metatranscriptomic analysis. We propose that active microbial populations respond primarily to changes in hydrology, pH, and nutrient availability. The increased microbial carbon export observed over winter may have ramifications for climate–soil feedbacks in the PCTR.


Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
Changins
Institute:
Aucun institut
Subject(s):
Ingénierie
Date:
2018-12
Pagination:
14 p.
Published in:
The ISME Journal
Numeration (vol. no.):
2019, vol. 13, pp. 950-963
DOI:
ISSN:
1751-7362
Appears in Collection:



 Record created 2019-03-05, last modified 2019-04-23

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