Microbial Community, Newly Sequestered Soil Organic Carbon, and δ15N Variations Driven by Tree Roots

Abstract

Rhizosphere microbes in forests are key elements of the carbon sequestration of terrestrial ecosystems. To date, little is known about how the diversity and species interactions of the active rhizomicrobial community change during soil carbon sequestration and what interactions drive these changes. In this study, we used a combination of DNA and stable isotope method to explore correlations between the composition of microbial communities, N transformation, and the sequestration de novo of carbon in soils around Pinus tabuliformis and Quercus variabilis roots in North China. Rhizosphere soils from degraded lands, primary stage land (tree roots had colonized in degraded soil for 1 year), and nature forest were sampled for analyses. The results showed that microbial communities and newly sequestered soil organic carbon (SOC) contents changed with different tree species, environments, and successive stages. The fungal unweighted and weighted UniFrac distances could better show the different microbial species structures and differences in successive stages. Newly sequestered SOC was positively correlated with the bacterial order Rhizobiales (in P. tabuliformis forests), the fungal order Russulales (in Q. variabilis forests), and δ 15 N. Consequently, the bacterial order Rhizobiales acted as an important taxa for P. tabuliformis rootdriven carbon sequestration, and the fungal order Russulales acted as an important taxa for Q. variabilis root-driven carbon sequestration. The two plant species allocated root exudates to different portion of their root systems, which in turn altered microbial community composition and function. The δ 15 N of soil organic matter could be an important indicator to estimate root-driven carbon sequestration.

Allium cepa L. Inoculation with a Consortium of Plant Growth-Promoting Bacteria: Effects on Plants, Soil, and the Autochthonous Microbial Community

“…Several PGPB have been shown to have the ability to increase soil carbon levels. However, organic carbon arises from interactions between roots and the rhizospheric microbial community and is influenced by many environmental factors (e.g., nutrient availability, pH, moisture, climatic conditions, atmospheric CO 2 ) [ 46 ]. The presence of bacterial inoculum also promotes positive changes in the richness and composition of the soil microbial community.…”

Local Geomorphological Gradients and Land Use Patterns Play Key Role on the Soil Bacterial Community Diversity and Dynamics in the Highly Endemic Indigenous Afrotemperate Coastal Scarp Forest Biome

“…In the last three decades, there has been increased interest in ecology of forest soils, partly due to the interlinkage of above-ground and below-ground soil microenvironments in contributing to the biodiversity-ecosystem functioning of forests. There is a general consensus that forest soils are a hotspot of dynamic bioprocesses facilitated by complex interactions of a multifaceted microbiome and above-ground vegetation critical in executing the key ecosystem functions such as primary production, litter decomposition, and organic matter mineralization (Sun et al, 2016;Lladó et al, 2017;Osburn et al, 2019;Song et al, 2020).…”

Studies on correlations between soil chemistry and bacterial population in rhizosphere of Bt and non-Bt cotton and characterization of rhizobacteria

“…Plant-microbe interactions have revealed that crops are talented to figure out respective rhizosphere microbiomes. A change in the rhizosphere chemistry due to altered root exudation or decayed plant material added to the soil may influence the microbial population and its community surrounding the roots [45]. The present results suggest no adverse impact of Bt cotton on the soil attributes and availability of nutrients for bacterial growth.…”