Variations in iron-bound organic carbon in soils along an altitude gradient and influencing factors in a subtropical mountain ecosystem of southern China
Kai Xiong, Xinyu Jiang, Shaoqiang Huang, Jinshun Guan, Xiangbo Zou, Chuangting Chen, Tiancheng Zhou, Cao Kuang, Ji Ye, Shiqin Yu, Heng Jiang, Bin Huang
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引用次数: 0
Abstract
Purpose
The main factors governing iron-bound organic carbon (Fe-bound OC) formation under different environmental conditions have been less well identified. In this study, we investigated the distribution of Fe-bound OC and the influencing factors in soils of a typical subtropical mountain ecosystem.
Materials and methods
Soil samples at different altitudes (402–1653 m) and depths (0–20 cm, 20–40 cm, and 40–60 cm) in the Nanling Mountains of southern China were collected. The influence of soil property indicators and microbial diversity characteristics on the formation of Fe-bound OC was explored.
Results
The Fe-bound OC content in the soils ranged from 1.40 ± 1.32 g/kg to 15.09 ± 3.57 g/kg, accounting for an average of 23.49 ± 13.03% of the total organic carbon (TOC), and generally increased with altitude and exhibited significantly higher values at the soil depth of 0–20 cm, while its proportion to TOC (fFe-OC) gradually increased as soil depth increased. The more significant indicators in explaining the variation of Fe-bound OC include TOC, particulate organic carbon (POC), free iron oxides (Fed), amorphous iron oxides (Feo), complexed iron oxides (Fep), Feo/Fed, pH, Ca, sand and silt. Feo/Fed was strongly linearly correlated with Fe-bound OC, thus can be a good predictor of Fe-bound OC content. RDA analysis showed that Fe-bound OC/fFe-OC had a relatively closer correlation with bacterial phyla including Proteobacteria, Actinobacteriota, Chloroflexi and Firmicutes.
Conclusions
The attitude gradient and soil depth significantly influence the content of Fe-bound OC. The distribution of Fe-bound OC exhibited a certain correlation with both biotic and abiotic factors.
期刊介绍:
The Journal of Soils and Sediments (JSS) is devoted to soils and sediments; it deals with contaminated, intact and disturbed soils and sediments. JSS explores both the common aspects and the differences between these two environmental compartments. Inter-linkages at the catchment scale and with the Earth’s system (inter-compartment) are an important topic in JSS. The range of research coverage includes the effects of disturbances and contamination; research, strategies and technologies for prediction, prevention, and protection; identification and characterization; treatment, remediation and reuse; risk assessment and management; creation and implementation of quality standards; international regulation and legislation.