Abstract Soil microorganisms are central to soil nutrient cycle by mediating organic matter decomposition and nutrient transformation. However, how changes in their physical and chemical environment across developmental stages of forest plantations accompanied by influence of the metabolic activity and nutrient use efficiency of rhizosphere microbes, and consequently, soil nutrient dynamics, remains poorly understood. We investigated rhizosphere soil microbial carbon and nitrogen use efficiencies (CUE and NUE) in subtropical Pinus massoniana plantations across 5, 9, 19, 29 and 35 years, for both growing and non‐growing seasons. Soil microbial CUE and NUE were consistently higher in the non‐growing season than in the growing season, likely due to higher nitrogen and lower carbon (C) content in litter and total potassium (K) concentration, which altered microbial substrate availability. Across stand development, CUE and NUE followed a pattern of initial increase, subsequent decline and later recovery. During the growing season, changes in CUE were mainly positively influenced by litter N content, whereas in the non‐growing season, CUE was positively associated with rhizosphere soil total K concentration. These shifts in soil CUE and NUE across stand development stages were further linked to changes in enzyme activities, with β‐glucosidase and peroxidase negatively associated with CUE and leucine aminopeptidase positively associated with NUE. Across stand ages, both CUE and NUE followed a non‐linear trajectory, suggesting complex interactions between litter inputs and rhizosphere available nutrient over time. Synthesis and applications . Microbial nutrient processing is strongly shaped by seasonal stoichiometric conditions and enzyme‐mediated substrate decomposition. This highlights the importance of considering seasonal and developmental stage‐specific management to optimize microbial function for improved forest productivity and carbon storage.
Xue et al. (Sun,) studied this question.