Linkage of microbial living communities and residues to soil organic carbon accumulation along a forest restoration gradient in southern China

Abstract

Background Forest restoration has been considered an effective method to increase soil organic carbon (SOC), whereas it remains unclear whether long-term forest restoration will continuously increase SOC. Such large uncertainties may be mainly due to the limited knowledge on how soil microorganisms will contribute to SOC accumulation over time. Methods We simultaneously documented SOC, total phospholipid fatty acids (PLFAs), and amino sugars (AS) content across a forest restoration gradient with average stand ages of 14, 49, 70, and > 90 years in southern China. Results The SOC and AS continuously increased with stand age. The ratio of fungal PLFAs to bacterial PLFAs showed no change with stand age, while the ratio of fungal AS to bacterial AS significantly increased. The total microbial residue-carbon (AS-C) accounted for 0.95–1.66 % in SOC across all forest restoration stages, with significantly higher in fungal residue-C (0.68–1.19 %) than bacterial residue-C (0.05–0.11 %). Furthermore, the contribution of total AS-C to SOC was positively correlated with clay content at 0–10 cm soil layer but negatively related to clay content at 10–20 cm soil layer. Conclusions These findings highlight the significant contribution of AS-C to SOC accumulation along forest restoration stages, with divergent contributions from fungal residues and bacterial residues. Soil clay content with stand age significantly affects the divergent contributions of AS-C to SOC at two different soil layers.

Faster accumulation and greater contribution of glomalin to the soil organic carbon pool than amino sugars do under tropical coastal forest restoration

“…Vegetation restoration could enhance plant‐C inputs and in tandem stimulate soil microbial activities (Hu et al, 2020). Microbial products mainly accumulate in soils via microbial decomposition and turnover (Liang, 2020; Zhang et al, 2021). However, the contribution of GRSP and amino sugars to the SOC pool decreased along the afforestation chronosequence (Figure 3), suggesting an increase in the contribution of plant‐derived C to the SOC pool with forest restoration.…”

“…Furthermore, there is no consensus on the contribution of necromass to the SOC pool during vegetation restoration (Guo et al, 2021). A recent study showed that the concentrations of PLFAs and amino sugars respond differently to forest restoration in a subtropical region with divergent contributions of fungi or bacteria to the SOC pool via physical protection pathways (Zhang et al, 2021). Especially microbial communities and biomasses might vary with aggregate sizes due to their difference in microhabitats (Gupta & Germida, 2015), hence influencing the accumulation of amino sugars in soil aggregates.…”

“…Furthermore, there is no consensus on the contribution of necromass to the SOC pool during vegetation restoration (Guo et al, 2021). A recent study showed that the concentrations of PLFAs and amino sugars respond differently to forest restoration in a subtropical region with divergent contributions of fungi or bacteria to the SOC pool via physical protection pathways (Zhang et al, 2021).…”

Soil organic carbon regulation from chemistry in top- but microbial community in subsoil in eastern coastal China poplar plantations

“…Previous studies have suggested that SOC storage is driven by soil physicochemical properties (pH, moisture, total N, total P, available C, available N, and available P), microbes (fungal and bacterial decomposition groups), and plants (plant community and plant litter quality). Among the dozens of biotic and abiotic factors affecting SOC storage (Averill et al, 2014;Wu et al, 2017;Luo et al, 2020;Chen et al, 2021;Wang et al, 2021;Zhang et al, 2021), soil properties have received much attention. For example, N limits C storage in terrestrial ecosystems, even in N-rich tropical forests (Lu et al, 2021).…”

Soil organic carbon primarily control the soil moisture characteristic during forest restoration in subtropical China

“…In forest ecosystems, land-use changes resulting from natural vegetation restoration can significantly alter carbon storage and fixation (Zhang and Shangguan, 2016). Forest restoration influences the equilibrium between the carbon input and output processes from plant and microbial sources by altering the soil carbon pool (Jastrow et al, 2007;Zhang et al, 2021). According to Erskine et al (2006), trees can add carbon to the soil, and this process can be affected by the tree species and the external environment.…”