Microbiological indicators of soil carbon dynamics

Microorganisms play a key role in the dynamics of soil organic matter (SOM) stocks, redistributing carbon (C) among microbial biomass growth, respiration, polymer synthesis, and intracellular and extracellular enzymatic processes. This paper provides a review of microbiological indicators used to study the decomposition, transformation, and stabilization of SOM, as well as their application in modeling soil C dynamics. This study examines microbiological parameters of the carbon cycle, such as microbial biomass C, soil enzymatic activity, microbial necromass C, C use efficiency (CUE), basal respiration, and microbial community structure. Methods for determining these indicators, their interpretation, and examples of their application in mathematical models are discussed. Given that microbial necromass constitutes a significant portion of SOM and that CUE is a key parameter balancing C mineralization and stabilization, integrating microbiological data into predictive models can significantly improve their accuracy. Quantitative determination of microbiological indicators of the С cycle under various soil and ecological conditions is essential for studying the mechanisms of microbial transformation and stabilization of SOM.