Peatland Microbial Community Composition Is Driven by a Natural Climate Gradient

James Seward; Michael A. Carson; L. J. Lamit; Nathan Basiliko; Joseph B. Yavitt; Erik Lilleskov; Christopher W. Schadt; Dave Solance Smith; Jim Mclaughlin; Nadia Mykytczuk; Shanay Willims-Johnson; Nigel Roulet; Tim Moore; Lorna Harris; Suzanna Bräuer

doi:10.1007/s00248-020-01510-z

Peatland Microbial Community Composition Is Driven by a Natural Climate Gradient

Formally Refereed

Authors:

James Seward, Michael A. Carson, L. J. Lamit, Nathan Basiliko, Joseph B. Yavitt, Erik Lilleskov, Christopher W. Schadt, Dave Solance Smith, Jim Mclaughlin, Nadia Mykytczuk, Shanay Willims-Johnson, Nigel Roulet, Tim Moore, Lorna Harris, Suzanna Bräuer

Year:

2020

Type:

Scientific Journal

Station:

Northern Research Station

DOI:

https://doi.org/10.1007/s00248-020-01510-z

Source:

Microbial Ecology

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Abstract

Peatlands are important players in climate change–biosphere feedbacks via long-termnet carbon (C) accumulation in soil organic matter and as potential net C sources including the potent greenhouse gas methane (CH₄). Interactions of climate, site-hydrology, plant community, and groundwater chemical factors influence peatland development and functioning, including C dioxide (CO₂) and CH₄ fluxes, but the role of microbial community composition is not well understood. To assess microbial functional and taxonomic dissimilarities, we used high throughput sequencing of the small subunit ribosomal DNA (SSU rDNA) to determine bacterial and archaeal community composition in soils from twenty North American peatlands. Targeted DNA metabarcoding showed that although Proteobacteria, Acidobacteria, and Actinobacteria were the dominant phyla on average, intermediate and rich fens hosted greater diversity and taxonomic richness, as well as an array of candidate phyla when compared with acidic and nutrient-poor poor fens and bogs. Moreover, pH was revealed to be the strongest predictor of microbial community structure across sites. Predictive metagenome content (PICRUSt) showed increases in specific genes, such as purine/pyrimidine and amino-acid metabolism in mid-latitude peatlands from 38 to 45° N, suggesting a shift toward utilization of microbial biomass over utilization of initial plant biomass in these microbial communities. Overall, there appears to be noticeable differences in community structure between peatland classes, as well as differences in microbial metabolic activity between latitudes. These findings are in line with a predicted increase in the decomposition and accelerated C turnover, and suggest that peatlands north of 37° latitude may be particularly vulnerable to climate change.

Keywords

Peatlands, Microbiology, Carbon cycling, Climate change

Citation

Seward, James; Carson, Michael A.; Lamit, L.J.; Basiliko, Nathan; Yavitt, Joseph B.; Lilleskov, Erik; Schadt, Christopher W.; Smith, Dave Solance; Mclaughlin, Jim; Mykytczuk, Nadia; Willims-Johnson, Shanay; Roulet, Nigel; Moore, Tim; Harris, Lorna; Bräuer, Suzanna. 2020. Peatland Microbial Community Composition Is Driven by a Natural Climate Gradient. Microbial Ecology. 80(3): 593-602. https://doi.org/10.1007/s00248-020-01510-z.