Closely Located but Totally Distinct: Highly Contrasting Prokaryotic Diversity Patterns in Raised Bogs and Eutrophic Fens

Abstract

Large areas in Northern Russia are covered by extensive mires, which represent a complex mosaic of ombrotrophic raised bogs, minerotrophic and eutrophic fens, all in a close proximity to each other. In this paper, we compared microbial diversity patterns in the surface peat layers of the neighbouring raised bogs and eutrophic fens that are located within two geographically remote mire sites in Vologda region using 16S rRNA gene sequencing. Regardless of location, the microbial communities in raised bogs were highly similar to each other but were clearly distinct from those in eutrophic fens. Bogs were dominated by the Acidobacteria (30%–40% of total 16S rRNA gene reads), which belong to the orders Acidobacteriales and Bryobacterales. Other bog-specific bacteria included the Phycisphaera-like group WD2101 and the families Isosphaeraceae and Gemmataceae of the Planctomycetes, orders Opitutales and Pedosphaerales of the Verrucomicrobia and a particular group of alphaproteobacteria within the Rhizobiales. In contrast, fens hosted Anaerolineae-affiliated Chloroflexi, Vicinamibacteria- and Blastocatellia-affiliated Acidobacteria, Rokubacteria, uncultivated group OM190 of the Planctomycetes and several groups of betaproteobacteria. The Patescibacteria were detected in both types of wetlands but their relative abundance was higher in fens. A number of key parameters that define the distribution of particular bacterial groups in mires were identified.

Rewiring of peatland plant–microbe networks outpaces species turnover

“…Moreover, our study confirms previous suggestions that enviro–climatic conditions are important drivers that underlie the composition of the vegetation, and that changes in these drivers result in alterations of the plant community (Gunnarsson et al 2002, Pinceloup et al 2020) and associated biotic interactions (Wiedermann et al 2007). Indeed, we note that site‐specificity of plant communities extends to the prokaryotic community, a pattern that is likely explained by the strong links between plant and microbial communities (Chronakova et al 2019, Ivanova et al 2020). Despite the variation in prokaryotic community composition between sites, the archaea to bacteria ratio remains strikingly stable, suggesting that both microbial groups are equally affected by alterations in enviro–climatic conditions.…”

“…These genera have been previously found in soils, and have been characterised as strictly aerobic, moderately acidophilic and chemoorganotrophic mesophiles. Methylacidophilaceae include methane‐oxidizing genera, but there is no evidence that the members of this family present in peatlands are involved in methane cycling (Ivanova et al 2020). This underlies the fact that it can be difficult to confidently predict the function of uncultivated bacterial species.…”

“…Following the train of thought that changes in environmental conditions cause shifts in the composition of peatland plant communities (Vitt and Slack 1975, Robroek et al 2017, Norby et al 2019), convergent shifts in the microbial community can be expected. Indeed, peatland microbial community structure and activity are strongly connected to plant community assemblage (Bragina et al 2014, Chronakova et al 2019, Martí et al 2019b, Ivanova et al 2020). Hence, interactions between plant and microorganisms are the cornerstone that shape carbon‐related processes in peatlands (Lindo et al 2013) and it is critical that we understand how enviro–climatic change affects these interactions to forecast the consequences for ecosystem processes (Kostka et al 2016).…”

Rewiring of peatland plant-microbe networks outpaces species turnover

“…Moreover, our study confirms previous suggestions that enviro-climatological conditions are important drivers that underlie the composition of the vegetation, and that changes in these drivers result in alterations of the plant community (Gunnarsson et al 2002, Pinceloup et al 2020) and associated biotic interactions (Wiedermann et al 2007). Indeed, we note that site-specificity of plant communities is paralleled in the prokaryotic community, a pattern that is likely explained by the strong links between plant and microbial communities (Chronakova et al 2019;Ivanova et al 2020). Despite the variation in prokaryotic community composition between sites, the archaea to bacteria ratio remains strikingly stable.…”

“…Indeed, peatland microbial community structure and activity are strongly connected to plant community assemblage (Bragina et al 2014, Chronakova et al 2019, Martí et al 2019b, Ivanova et al 2020.…”