Shifts in microbial diversity through land use intensity as drivers of carbon mineralization in soil

Abstract

a b s t r a c tLand use practices alter the biomass and structure of soil microbial communities. However, the impact of land management intensity on soil microbial diversity (i.e. richness and evenness) and consequences for functioning is still poorly understood. Here, we addressed this question by coupling molecular characterization of microbial diversity with measurements of carbon (C) mineralization in soils obtained from three locations across Europe, each representing a gradient of land management intensity under different soil and environmental conditions. Bacterial and fungal diversity were characterized by high throughput sequencing of ribosomal genes. Carbon cycling activities (i.e., mineralization of autochthonous soil organic matter, mineralization of allochthonous plant residues) were measured by quantifying 12 C-and 13 C-CO 2 release after soils had been amended, or not, with 13 C-labelled wheat residues. Variation partitioning analysis was used to rank biological and physicochemical soil parameters according to their relative contribution to these activities. Across all three locations, microbial diversity was greatest at intermediate levels of land use intensity, indicating that optimal management of soil microbial diversity might not be achieved under the least intensive agriculture. Microbial richness was the best predictor of the C-cycling activities, with bacterial and fungal richness explaining 32.2 and 17% of the intensity of autochthonous soil organic matter mineralization; and fungal richness explaining 77% of the intensity of wheat residues mineralization. Altogether, our results provide evidence that there is scope for improvement in soil management to enhance microbial biodiversity and optimize C transformations mediated by microbial communities in soil.

The active microbial diversity drives ecosystem multifunctionality and is physiologically related to carbon availability in Mediterranean semi‐arid soils

“…Indeed, plant cover – particularly the presence of Pinus trees – has been found to raise the abundance of Basidiomycota (Tardy et al . ) and a similar trend was found here at forest sites with the highest DOC content and lignocellulosic compounds with a high C/N ratio (i.e. pine needles).…”

Do composition and diversity of bacterial communities and abiotic conditions of spring water reflect characteristics of groundwater ecosystems exposed to different agricultural activities?

“…Differences between sampling sites regarding bacterial diversity and relative taxonomic abundance are furthermore confirmed by analysis of principal coordinates of bacterial OTU composition at the family level. We found a significant effect of sampling site on OTU composition ( R 2 = 0.311; p = 0.031; PERMANOVA), a result that was previously reported by others (Kaiser et al., ; Ma, Ibekwe, Yang, & Crowley, ; Tardy et al., ). However, the effect of sampling site on OTU composition was low (31%) in comparison to findings reported by Ma et al.…”

Deciphering the associations between soil microbial diversity and ecosystem multifunctionality driven by long‐term fertilization management

“…Various soil biological processes ultimately determine the potential of soils to sequester and release C (Bender et al., ), which is largely controlled by the C‐cycle enzyme activity (Amundson et al., ). Moreover, it is generally assumed that microbial diversity may explain a substantial component of C mineralization (Tardy et al., ). Collectively, all of these findings suggest that the role of the C‐cycle enzyme activity, as a predictor of EMF, was determined by the microbial diversity in soils (Figure ).…”