School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Sci Total Environ. 2021 Apr 1;763:142972. doi: 10.1016/j.scitotenv.2020.142972. Epub 2020 Oct 16.
Mangrove forests cover only 0.1% of the world's continental area; however, these are a substantial carbon sink owing to the high primary production and low rate of decomposition of soil organic matter (SOM). The extremely low decomposition rate of SOM in mangrove forests is believed to be caused by low oxygen and nutrient availability as well as recalcitrant biomass from mangrove. However, only a few studies have addressed the microbial mechanism that plays a key role in the decomposition of SOM. In this study, the decomposition of SOM were determined by conducting a field survey and an lab incubation experiment using soil samples from mangrove forests in three regions; Okinawa, Shenzhen, and Hong Kong. In particular, we examined the occurrence of the enzymic latch mechanism, which involves phenolic inhibition of enzymic decomposition, in mangrove forest soils that highlights the importance of phenol oxidase as a key controlling factor. The results clearly showed that enzymic latch involved in the accumulation of SOM in the mangroves of Shenzhen and Hong Kong, whereas the accumulation of SOM in Okinawa was controlled by other mechanisms, such as the iron gate mechanism, which involves stabilization of soil carbon in iron-SOM complexes. The characteristics of mangrove forests, such as iron concentration, were shown as substantial determination factors in the dynamics of SOM. We concluded that the decomposition of SOM were strongly affected by the characteristics of mangrove forests, and the occurrence of enzymic latch in mangrove forests has a potential application in geoengineering technology to enhance the carbon sequestration capacity of mangrove forests.
红树林仅占世界大陆面积的 0.1%；然而，由于高初级生产力和土壤有机质（SOM）分解率低，这些地方是一个巨大的碳汇。红树林中 SOM 极低的分解率被认为是由于低氧和养分供应以及红树林中顽固的生物质造成的。然而，只有少数研究探讨了在 SOM 分解中起关键作用的微生物机制。在这项研究中，通过对三个地区（冲绳、深圳和香港）红树林的土壤样本进行野外调查和实验室培养实验，确定了 SOM 的分解。特别是，我们研究了酶锁机制的发生情况，这种机制涉及酚类对酶分解的抑制，强调了酚氧化酶作为关键控制因素的重要性。结果清楚地表明，深圳和香港红树林中存在与 SOM 积累有关的酶锁机制，而冲绳的 SOM 积累则受其他机制控制，如涉及土壤碳在铁-SOM 复合物中稳定化的铁闸机制。红树林的特征，如铁浓度，被证明是 SOM 动态的重要决定因素。我们得出结论，SOM 的分解受到红树林特征的强烈影响，红树林中酶锁的发生在增强红树林的碳固存能力的地球工程技术中有潜在的应用。
