Global pattern of warming effects on microbial respiration is explained by soil microbial biomass carbon and nitrogen

• Published in: Catena (Giessen) Vol. 250; p. 108728
• Main Author: Liang, Guopeng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025
• Subjects: catenas; climate; Experimental warming; microbial biomass; microbial carbon; nitrogen; soil; Soil microbial biomass carbon and nitrogen; Soil microbial respiration; Soil microbial variables; Soil organic carbon; species diversity; Soil microbial variables; Soil microbial respiration; Soil microbial biomass carbon and nitrogen; Soil organic carbon; Experimental warming
• ISSN: 0341-8162
• DOI: 10.1016/j.catena.2025.108728

•Warming effects on soil microbial respiration (MR) are modest.•Warming effects on MR increase with warming level, mean annual precipitation, and soil organic carbon.•Warming increases MR by stimulating soil microbial biomass carbon and nitrogen.•Warming-induced increase in MR does not lead to soil organic carbon loss. As one of the largest fluxes in the global carbon (C) cycle, soil microbial respiration (MR) refers to the C losses from organic matter decomposition by microbes. Therefore, soil microbial processes are urged to be explicitly included in soil C cycling models to improve their predictive ability. However, unknowns remain regarding which soil microbial variables can be used to explain warming effects on MR. Herein, I collected data from 271 field observations worldwide, also allowing me to determine whether a warming-induced increase in MR can lead to soil organic C (SOC) loss. Despite the minor effect of warming on MR, I found that warming could increase soil microbial biomass C and nitrogen (N) and then enhance MR. However, soil microbial abundance (e.g. microbial biomass [fungi and bacteria]), alpha diversity, composition (e.g. fungi/bacteria), and activity (e.g. enzymes related to C or N cycling) did not explain the global pattern of warming effects on MR well. The insignificant relationship between response ratios of SOC and MR indicates that the increase in MR by warming does not necessarily decrease SOC content. This study suggests that soil microbial biomass C and N may be the priority variables that can be incorporated into models for better predicting SOC cycling under future climate warming.