Figure 7
From: Linking soil microbial community dynamics to straw-carbon distribution in soil organic carbon
The conceptual scheme of the straw decomposition with the succession of microbial populations and their probable role in the fractionation of the straw-derived C. After straw inputs, amount of DOC (
) is derived from straw-C (
), and can be firstly utilized by fast-growing and cellulolytic microbes (
), who will produce microbial-derived organic C compounds (
). Part of these C compounds can be directly absorbed on mineral surfaces with relatively lower (
) or higher sorptive affinity (
), while some of the adsorbed C with relatively lower sorptive affinity might be desorbed and further be degraded by certain olipotrophic microbes (
) (e.g., unclassified Acidobacteriaceae) in the following phase. The other part can be utilized directly by certain microbes (
), such as slow-growing microbe (e.g. Edaphobacter) and N-related microbe (e.g. Burkholderia-Paraburkholderia and Bradyrhizobium). The byproducts C (
) (e.g., aromatic C, phenolic acids, extracellular polymeric substances) from the above microbes will be adsorbed in mineral surface with relatively higher sorptive affinity (
) and contributed to MaOC. During the whole process of straw decomposition, the structural straw C, such as lignin and hemicellulose, accumulated and formed POC (
). But this part of POC may be also decomposed by microbes (
) in long-term, and the microbial-derived C from them (
) might absorb in mineral surface (
). However, this link has not been confirmed in this study, thus it is depicted as dotted arrow.
