Thresholds in aridity and soil carbon-to-nitrogen ratio govern the accumulation of soil microbial residues

Abstract Microbial moribunds after microbial biomass turnover (microbial residues) contribute to the formation and stabilization of soil carbon pools; however, factors influencing their accumulation on a global scale remain unclear. Here, we synthesized data for 268 amino sugar concentrations (biomarkers in grassland forest ecosystems meta-analysis. We found that organic carbon, carbon-to-nitrogen ratio, aridity index were key predicted residual accumulation. Threshold ratios identified (~0.768 ~9.583, respectively), above which residues decreased sharply. The threshold was associated with humid climate range. suggest ratio may coincide sharp decrease fungal abundance. Although dominant vary between ecosystem zone, being important throughout, our findings environment govern residue