Predicting the structure and functions of peatland microbial communities from Sphagnum phylogeny, anatomical and morphological traits and metabolites

• Published in: Journal of Ecology
• Main Authors: Sytiuk, Anna, Cereghino, Regis, Hamard, Samuel, Delarue, Frederic, Guittet, Amelie, Barel, Janna M, Dorrepaal, Ellen, Kuttim, Martin, Lamentowicz, Mariusz, Pourrut, Bertrand, Robroek, Björn J M, Tuittila, Eeva-Stiina, Jassey, Vincent E J
• Other Authors: School of Forest Sciences, activities
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: functional traits; latitudinal gradient; metabolomics; microbial traits; peatlands; plant and microbial communities; plant–soil (below-ground) interactions; Sphagnum; Northern Sweden
• Online Access: https://erepo.uef.fi/handle/123456789/27079

1. Sphagnum mosses are keystone species in northern peatlands. Notably, they play an important role in peatland carbon (C) cycling by regulating the composition and activity of microbial communities. However, it remains unclear whether information on Sphagnum phylogeny and/or traits-based composition (i.e. anatomical and morphological traits and metabolites) can be used to predict the structure of microbial communities and their functioning. Here we evaluated whether Sphagnum phylogeny and traits predict additional variation in peatland microbial community composition and functioning beyond what would be predicted from environmental characteristics (i.e. climatic and edaphic conditions). 2. We collected Sphagnum a nd m icrobial d ata from five European peatlands distributed along a latitudinal gradient from northern Sweden to southern France. These data allowed us to assess Sphagnum anatomical and morphological traits and metabolites at different sites along changing environmental conditions. Using structural equation modelling (SEM) and phylogenetic distance analyses, we investigated the role of Sphagnum traits in shaping microbial community composition and functioning along with environmental conditions. 3. We show that microbial community composition and traits varied independently from both Sphagnum phylogeny and the latitudinal gradient. Specifically, the addition of Sphagnum traits to climatic and edaphic variables to the SEM allowed it to explain a larger proportion of the explained variance (R2). This observation was most apparent for the biomass of decomposers (+42%) and phototrophs (+19%), as well as for growth yield microbial traits (+10%). As such, that Sphagnum metabolites were important drivers for microbial community structure and traits, while Sphagnum anatomical and morphological traits were poor predictors. 4. Synthesis. Our results highlight that Sphagnum metabolites are more likely to influence peatland microbial food web structure and functioning than Sphagnum anatomical and morphological ...