Figure legends
Fig. 1 Conceptual diagram describing biologically driven soil organic (SOC) and inorganic carbon (SIC) cycling. SOC sources from plant litter and root exudates and SIC sources from respired CO2 among microorganisms and roots are highlighted (left diagram); and we hypothesize that microbial necromass play a role in SIC-to-SOC transition in accordance with the microbial carbon pump theory (right diagram).
Fig. 2 C components (i.e., soil inorganic carbon [SIC], soil organic carbon [SOC], and microbial residues) of coastal saline soils (n=94) in Yellow River Delta. (a ) The shifts in SIC, SOC, and microbial residue levels along a natural salinity gradient; (b ) associations among SOC, microbial residues, and SIC; (c ) structural equation modeling examining the underlying causal relationships among SIC, microbial residues, and SOC.