Soil pH dominance over livestock management in determining bacterial assemblages through a latitudinal gradient of European meadows and pastures

• Published in: Ecological indicators Vol. 155; p. 111063
• Main Authors: Raniolo, S., Maretto, L., Benedetti del Rio, E., Cournut, S., Cremilleux, M., Nowak, B., Michaud, A., Lind, V., Concheri, G., Stevanato, P., Squartini, A., Ramanzin, M., Sturaro, E.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2023; Elsevier
• Subjects: Agricultural sciences; Ecology, environment; Grassland; Life Sciences; Meadow; Nutrient cycling; Pasture; Soil microbial diversity; Grassland; Meadow; Nutrient cycling; Soil microbial diversity; Pasture; Herbages; Cycle des éléments nutritifs; Prairie; Pâturages; Grassland Nutrient cycling Soil microbial diversity Pasture Meadow; Diversité microbienne du sol; Norvège; Italie; Norway; Italy; France
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2023.111063

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•Grasslands exhibit distinct taxonomic and functional profiles across regions.•Grasslands show consistent taxonomic and functional profiles despite management type.•Regions have a core microbiome of Firmicutes, Proteobacteria, and Actinobacteriota.•Soil pH influences microbial variability in taxonomic and functional profiles.•Nitrogen cycling potentials are influenced by region, soil pH, and organic carbon.
Grasslands represent key functional ecosystems due to their global contribution to macronutrients cycling and their role as reservoirs of microbial diversity. The strategic importance of these habitats rests on their involvement in carbon and nitrogen fluxes from the atmosphere to the soil, while at the same time offering extensive sites for livestock rearing. In this study the management type, differentiated in pasture or meadow, was investigated as a variable for its possible effects on overall bacterial diversity and specific genes related to functional guilds. Its contribution was compared to that of other variables such as region, soil pH, and soil organic carbon, to rank their respective hierarchies in shaping microbial community structure. A latitudinal gradient across the European continent was studied, with three sampling groups located in Norway, France, and Northern Italy. The applied methods involved 16S DNA metabarcoding for taxonomic classification and determination of the relative abundance of the bacterial component, and quantitative PCR for the genetic determinants of bacterial and archaeal nitrification, intermediate or terminal denitrification, and nitrogen fixation. Results indicated that soil pH exerted the dominant role, affecting high taxonomy ranks and functions, along with organic carbon and region, with whom it partly covaried. In contrast, management type had no significant influence on microbial community structure and quantitative counts of functional genes. This suggests an ecological equivalence between the impacts of pasture and meadow practices, which are both perturbations that share the aspect of vegetation withdrawal by browsing or cutting, respectively.