Recalcitrant organic carbon dominates peat carbon storage but remains environmentally sensitive
Year: 2026
Type: article
Abstract: Peatlands store vast amounts of organic carbon (OC), yet climate-induced water-table decline is increasingly threatening their long-term stability. Understanding the vertical heterogeneity of OC characteristics is crucial for predicting peat carbon dynamics in this context. However, estimates of this heterogeneity remain highly uncertain, as attention has focused mainly on total OC and vertical variations in OC composition remain poorly constrained. It masks shifts among OC components with contrasting decomposition potentials and environmental sensitivities. Here we investigated variations in peat OC components (labile, intermediate, recalcitrant OC; LOC, IOC, ROC) from three distinct depth intervals (i.e. 0–10 cm surface, 10–20 cm subsurface, and >20 cm deep) in peatlands across four regions of China. We found that OC components across all regions exhibited distinct vertical distribution patterns that diverged from total OC. Despite accounting for over 70% of total OC, ROC showed the strongest sensitivity to both biological (fungi: bacteria ratio) and non-biological (bulk density, P, and Al-oxides) properties. Increasing depth, synergized by regional climate, strengthened non-biological constraints while weakening microbial regulation, thereby reshaping the vertical distribution of OC components. In addition, Sphagnum peat supported higher OC concentrations across depth intervals, and was associated with more favorable biogeochemical properties (e.g. higher C:P and fungi: bacteria ratios). These findings show that distinguishing OC components refines mechanistic understanding of the peatland OC stability, thereby improving predictive ability of peatland OC source-sink functions under future climate change.
Source: Environmental Research Letters
Authors: Bin Xia, Yao Gao, Chenyu Wang, Zhanyi Lin, Hui Zhang
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDGs: Climate action, Life on land
Open Access status: gold
Estimated APC paid: $3,045
OpenAlex ID: W7220968463