Background

Submerged soils are globally important both in natural and agricultural ecosystems and cover 5–7% of the global land surface. Therefore, processes in submerged soils are important for global biogeochemical cycles. These processes are strongly influenced by oxygen availability, i.e. redox potential.

Scope

This review aims to provide an overview of the role of redox potential in nutrient cycling, soil organic matter turnover and the effect of plants on nutrient cycling processes in submerged soil.

Conclusion

In submerged soils, the active terminal electron acceptor for reduction processes follows the sequence O₂, NO₃⁻, MnO_2, Fe³⁺, SO₄²⁻ and CO₂ where, in most cases organic matter, is the electron donor. Depletion of available organic matter during this sequence can limit the subsequent processes. Drying and rewetting of previously submerged soils have complex effects on nutrient cycling. Submerged soils often have higher organic matter content than aerobic soils which is due to chemical, metabolic and physical mechanisms. Plants have complex effects on processes in wetland soils resulting from release of oxygen from roots which can induce iron and methane oxidation around roots. However, plants can also increase methane release due to transport of methane via aerenchyma to the shoots. For a better understanding of processes in submerged soils, future investigations across scales, ranging from microscale to macroscale, are needed.

中文翻译：

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沉水土壤中的过程——将氧化还原电位、土壤有机质周转和植物与养分循环联系起来

背景

沉水土壤在自然和农业生态系统中都具有全球重要性，覆盖了全球 5-7% 的陆地表面。因此，沉水土壤中的过程对于全球生物地球化学循环很重要。这些过程受到氧气可用性，即氧化还原电位的强烈影响。

范围

本综述旨在概述氧化还原电位在养分循环、土壤有机质周转和植物对淹没土壤养分循环过程的影响中的作用。

结论

在沉水土壤中，还原过程的活性末端电子受体遵循 O ₂、NO ₃ ^-、MnO _2、 Fe ³⁺、SO ₄ ^2-和 CO ₂的顺序在大多数情况下，有机物是电子供体。在此过程中可用有机物的消耗会限制后续过程。先前淹没的土壤的干燥和再润湿对养分循环具有复杂的影响。由于化学、代谢和物理机制，沉水土壤的有机质含量通常高于好氧土壤。植物对湿地土壤中的过程具有复杂的影响，这是由于根部释放氧气而导致根部周围的铁和甲烷氧化。然而，由于甲烷通过通气组织运输到枝条，植物也可以增加甲烷释放。为了更好地了解淹没土壤中的过程，未来需要进行从微观尺度到宏观尺度的跨尺度调查。