Our results demonstrated that soil C and N mineralization coupled in the rhizosphere rather than in the bulk soils. By contrast, the decoupling of C min and N min in the bulk soils might be attributed to the lower level of MBC and extracellular enzyme activities. The coupling of C min and N min in rhizosphere soils could be triggered by root-soil interactions, resulting in the higher level of MBC, total organic C of soil, total N of soil, and extracellular enzyme activities. Furthermore, soil properties, microbial biomass C (MBC) and extracellular enzyme activities showed substantial paths affecting C min and N min using structural equation model. We found a significantly positive relationship between C min and N min in the rhizosphere soils across sites, whereas C min was not correlated with N min in the bulk soils. Soil C mineralization rates (C min) and net N mineralization rates (N min) were determined with laboratory incubation. We used the “soil adhering to fine roots after shaking” method to collect paired rhizosphere soils and bulk soils along an altitudinal forest gradient. This study aimed to identify interactions between soil C and N mineralization in rhizosphere soils and bulk soils at a large scale.

However, the interaction between soil C and N mineralization remain poorly understood in the rhizosphere soils. Rhizosphere is a hotspot for soil C and N biogeochemical cycling in terrestrial ecosystems.

Savin drivers download