Advances in Understanding the Interplay of Soil Carbon, Iron, and Arsenic Transformation

Soil biogeochemical processes play a critical role in regulating carbon, iron, and arsenic dynamics, with profound influences on ecosystem health and human well-being. The noted elements are closely coupled with each other. Soil carbon, the largest reservoir of the terrestrial biosphere, emerges as a potent tool in the fight against climate change. However, the proper control of soil carbon remains a big challenge. Numerous studies have highlighted the pivotal role of mineral protection, particularly iron minerals. Both biotic and abiotic iron oxidation have been shown to preserve soil organic carbon. Conversely, heterogeneous iron reduction not only releases soil organic carbon but also consumes it. Furthermore, the transformation of soil carbon and iron inevitably impacts arsenic dynamics, a significant environmental toxin. Iron oxides serve as the primary adsorption sites for arsenic in soil, and heterogeneous iron reduction is believed to be an important pathway leading to arsenic release. Additionally, the biotic reduction of arsenate to arsenite further enhances arsenic release. The presence of rich organic matter may facilitate the methylation of arsenic, mediated by sulfate-reducing bacteria. Viruses may facilitate the functional horizontal gene transfer. Microorganisms, including bacteria, archaea, fungi, and viruses, are the primary drivers of soil carbon, iron, and arsenic transformation. A comprehensive understanding of the interplay of soil carbon, iron, and arsenic transformation is essential for sustainable soil management.

Recent advancements in microbial ecology, molecular biology, and biogeochemistry have revealed the intricate interplay between the transformation of carbon, iron, and arsenic in soils. This Research Topic aims to consolidate cutting-edge research on the novel understanding of biotic processes governing soil carbon, iron, and arsenic dynamics. It seeks to provide insights into the fundamental mechanisms underlying these processes, explore their implications at the ecosystem scale, and offer practical applications for sustainable soil management and environmental remediation.

This Research Topic will include research articles, perspectives, and reviews, focusing on but not limited to the following scopes:
- Carbon-iron, carbon-arsenic, iron-arsenic coupling in soils and sediments.
- The interaction of iron mineral-soil organic carbon-microorganisms.
- Biotic processes or electron transfer involved in the elemental coupling.
- Transfer of the functional microorganism or genes in the environment.
- Measures to enhance soil carbon sequestration.
- Measures to reduce soil methane emission.
- Measures to reduce soil arsenic risk.
- Novel method to track the biotic process.
- Other closely associated research.