Soil Parameters Drive the Structure, Diversity and Metabolic Potentials of the Bacterial Communities Across Temperate Beech Forest Soil Sequences

Abstract

Soil and climatic conditions as well as land cover and land management have been shown to strongly impact the structure and diversity of the soil bacterial communities. Here, we addressed under a same land cover the potential effect of the edaphic parameters on the soil bacterial communities, excluding potential confounding factors as climate. To do this, we characterized two natural soil sequences occurring in the Montiers experimental site. Spatially distant soil samples were collected below Fagus sylvatica tree stands to assess the effect of soil sequences on the edaphic parameters, as well as the structure and diversity of the bacterial communities. Soil analyses revealed that the two soil sequences were characterized by higher pH and calcium and magnesium contents in the lower plots. Metabolic assays based on Biolog Ecoplates highlighted higher intensity and richness in usable carbon substrates in the lower plots than in the middle and upper plots, although no significant differences occurred in the abundance of bacterial and fungal communities along the soil sequences as assessed using quantitative PCR. Pyrosequencing analysis of 16S ribosomal RNA (rRNA) gene amplicons revealed that Proteobacteria, Acidobacteria and Bacteroidetes were the most abundantly represented phyla. Acidobacteria, Proteobacteria and Chlamydiae were significantly enriched in the most acidic and nutrient-poor soils compared to the Bacteroidetes, which were significantly enriched in the soils presenting the higher pH and nutrient contents. Interestingly, aluminium, nitrogen, calcium, nutrient availability and pH appeared to be the best predictors of the bacterial community structures along the soil sequences.

Driving forces of soil bacterial community structure, diversity, and function in temperate grasslands and forests

“…1 ). These results are consistent with previous studies on grasslands 24 and temperate beech forests 25 . The most abundant phylotype (3.99% ± 2.44) is an uncultured member of the Subgroup 6 of the Acidobacteria .…”

Native soils with their microbiotas elicit a state of alert in tomato plants

“…This means that, notwithstanding the significant abiotic and biotic differences of the soils (Poli et al ., ), tomato roots seem to display a broadly similar expression profile when grown in native soils, as compared with roots grown in the control substrate. Soil is considered the primary force driving plant–microbiota diversity (Jeanbille et al ., ); our present data reveal that soil is also a key factor in shaping the molecular profile in tomato.…”

Bacterial microbiomes of individual ectomycorrhizal Pinus sylvestris roots are shaped by soil horizon and differentially sensitive to nitrogen addition

“…Different soil types have been shown to affect bacterial microbiomes of Fagus sylvatica roots (Nicolitch et al, 2016), although that study did not distinguish the possible influence of different ectomycorrhizal fungi. Other studies have shown effects of soil chemistry on composition of soil microbial communities including soil pH, and nutrient availability (Landesman et al, 2014;Jeanbille et al, 2016) and differences in the bioavailability of nutritive cations have been shown to impact the efficacy of mineral weathering bacterial communities (Lepleux et al, 2013). In the present study, we distinguished separate effects of soil from different horizons and of different ectomycorrhizal fungi on the bacterial microbiomes associated with P. sylvestris roots since clear differences between roots colonized by different fungi were present within the same soil horizon in unfertilized systems ( Table 2).…”