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.
Bibliographical noteFunding Information:
This study was supported by the funds from the Ministry of Education of Korea [ 2019R1A6A3A01091184 and 2020R1I1A2072824 ], the Ministry of Science and ICT of Korea [ 2019K1A3A1A80113041 and 2019K1A3A1A74107424 ], and the Ministry of Oceans and Fisheries of Korea [ 20170318 ].
© 2020 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal