Soil microbial diversity patterns of a lowland spring environment.
The Po river plain lowland springs comprise unique paradigms of managed environments. Their current locations used to be swamps that were drained 6-7 centuries ago, and had constant use ever since. Our aims were to identify the land use effects on the microbial communities of these soils, seek for associated diversity drivers and assess the applicability of ecology theories with respect to identified patterns. We screened the microbial diversity across a land use transect via high throughput sequencing of partial 16S rRNA gene amplicons. Land use had a major effect on soil properties and microbial community structures. Total organic carbon (TOC) and pH were major diversity drivers for Bacteria, while pH was important for Archaea. We identified the potential contribution of soil amendments to the indigenous microbial communities, and also gained insights about potential roles of taxa in the organic carbon turnover. Verrucomicrobia, coincided with the higher values of the recalcitrant organic carbon while Actinobacteria and Acidobacteria correlated with the more labile organic carbon. Finally, the higher diversity found in the less enzymatically active and relatively poorer in nutrients soils, may be explained to an extend by niche based theories like the resource heterogeneity hypothesis and Connell''s intermediate disturbance hypothesis. Multiplexed 16S rRNA gene amplicons from soil DNA extracts of samples derived from three soils (each in biological triplicates).