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Abstract Soil microbial communities play a critical role in soil carbon dynamics. However, knowledge gaps exist regarding responses of heterotrophic respiration to compound climate drivers. We conducted a field manipulative experiment in a semiarid grassland of northern China, exploring the effects of precipitation addition, nitrogen addition, warming and their interplays on soil microbial community and metabolic function. Results obtained demonstrate that main effects of precipitation and nitrogen enhanced microbial respiration through increased microbial biomass and nitrogen availability, whereas warming showed no evident effect. Furthermore, precipitation and nitrogen acted synergistically to stimulate respiration, whereas nitrogen and warming exerted antagonistic effects. Microbial carbon use efficiency was positively influenced by both nitrogen and warming, with precipitation interactively modulating these individual effects. These results highlight the complex interactions among multiple climate change factors in regulating microbial carbon cycling. We predict that alterations in microbial metabolic functions in resource-limited temperate grasslands will modify soil carbon–climate feedbacks by regulating soil carbon fluxes. The study advances understanding of climate change-carbon feedbacks through improved characterization of multi—factor interactions.
Zhou et al. (Fri,) studied this question.