Despite the recognized organic carbon (OC) sequestration potential of mangrove forests, the ongoing climate change and anthropogenic disturbances pose a great threat to these ecosystems. However, we currently lack the ability to mechanically understand and predict the consequences of such impacts, primarily because mechanisms underlying OC stabilization in these ecosystems remain elusive. Research into OC stabilization has focused on terrestrial soils and marine sediments for decades, overlooking the vegetated coastal ecosystems including mangroves. In terrestrial soils and marine sediments, it is widely accepted that OC stabilization is the integrated consequence of OM’s inherent recalcitrance, physical protection, and interactions with minerals and metals. However, related discussion is rarely done in mangrove soils, and recalcitrance of roots and high net ecosystem production (high primary production and low heterotrophic respiration) have been considered as a primary OC sequestration mechanism in mangrove peat and mineral soils, respectively. This review presents the available information on the mechanisms underlying OC stabilization in mangrove soils and highlights research questions that warrant further investigation. Primary OC stabilization mechanisms differ between mangrove peat and mineral soils. In mangrove mineral soils, physico-chemical stabilization processes are important, yet grossly understudied OC stabilization mechanisms. In mangrove peat, recalcitrance of mangrove roots and the inhibition of phenoloxidase under the anoxic condition may be the primary OC stabilization mechanisms. Salinity-induced OC immobilization likely plays a role in both type of soils. Finally, this review argues that belowground production and allochthonous inputs in mangrove forests are likely underestimated. More studies are needed to constrain C budgets to explain the enigma that mangrove OC keeps accumulating despite much higher decomposition (especially by large lateral exports) than previously considered.

中文翻译：

---

红树林土壤中有机碳稳定机制的研究进展

尽管红树林具有公认的有机碳（OC）封存潜力，但持续的气候变化和人为干扰对这些生态系统构成了巨大威胁。但是，我们目前缺乏从机械上理解和预测此类影响后果的能力，这主要是因为这些生态系统中的OC稳定基础机制仍然难以捉摸。OC稳定化研究数十年来一直集中在陆地土壤和海洋沉积物上，忽略了包括红树林在内的植被繁茂的沿海生态系统。在陆地土壤和海洋沉积物中，OC稳定是OM固有的顽固性，物理保护以及与矿物和金属相互作用的综合结果，这一点已被广泛接受。但是，很少在红树林土壤中进行相关讨论，根系的顽固性和高生态系统净产量（高初级生产力和低异养呼吸）被认为是红树林泥炭和矿质土壤中主要的OC螯合机制。这篇综述提供了有关红树林土壤中OC稳定的基本机制的可用信息，并突出了值得进一步研究的研究问题。红树林泥炭和矿物土壤的主要OC稳定机制不同。在红树林矿物土壤中，物理化学稳定过程很重要，但对OC稳定机制的研究却很少。在红树林泥炭中，在缺氧条件下对红树林根的顽固和对酚氧化酶的抑制可能是主要的OC稳定机制。盐度诱导的OC固定化可能在两种土壤中都起作用。最后，这篇评论认为红树林中的地下生产和异源投入可能被低估了。需要进行更多的研究来限制C的预算，以解释尽管比以前考虑的分解（尤其是较大的横向出口）高得多的红树林OC仍在不断积累的谜团。