Fig. 1. Two contrasting pathways in determining the relationship between microbial CUE and SOC storage.

a, The first pathway indicates that a high CUE favours the accumulation of SOC storage through increased microbial biomass and by-products. b, The second pathway emphasizes that a high CUE stimulates SOC losses via increased microbial biomass and subsequent extracellular enzyme production that enhances SOC decomposition.