Carbon dynamics and greenhouse gas outgassing in an estuarine mangrove wetland with high input of riverine nitrogen

Lu, Zeyang1,2; Wang, Fenfang1,2; Xiao, Kai3; Wang, Yao1,2; Yu, Qibiao1,2; Cheng, Peng2; Chen, Nengwang1,2,4

2022-12-01

10.1007/s10533-022-00999-5

BIOGEOCHEMISTRY   Impact Factor & Quartile

0168-2563

1573-515X

The large amounts of organic carbon buried in mangrove wetlands are well recognized, but the lateral dissolved carbon export and greenhouse gas (GHGs) outgassing are often overlooked. In this study, we carried out seasonal observations of dissolved carbon and GHGs in an estuarine mangrove wetland with high input of riverine nitrogen in southeast China in 2019-2020. The results showed that the tidal range and season were the two main factors controlling the lateral dissolved carbon export including total alkalinity (TA), dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). The positive correlations between the average offsets of DIC, TA, DOC and tidal range confirmed the hydrological controls on the exchange of dissolved carbon between the mangrove creek and the estuary. The seasonal variability in temperature, groundwater export and freshwater input resulted in a larger carbon offset during low tidal range in spring and a smaller offset during high tidal range in fall. The mangrove creek acted as a net source of DIC, DOC, TA and GHGs. When the emissions of GHGs were calculated as CO2-equivalents, the average emission of CO2 was four times higher than that of N2O and the average emission of N2O was six times higher than that of CH4. In contrast with pristine mangroves, denitrification in mangrove wetlands with high input of riverine nitrogen played a crucial role in mineralization processes, leading to the production of DIC, TA and N2O. These biogeochemical processes may not be conducive to the blue carbon sequestration in mangrove soils. These findings suggested that there are mutual benefits between the reduced loss of blue carbon and the mitigation of eutrophication when restoring mangrove wetlands and reducing nitrogen pollution.

Coastal wetlands Blue carbon Denitrification CO2-equivalent Zhangjiang estuary

SCI

English

Others

[42276171] ; [41976138] ; [41907162]

Environmental Sciences & Ecology ; Geology

Environmental Sciences ; Geosciences, Multidisciplinary

WOS:000895664500001

SPRINGER

ENVIRONMENT/ECOLOGY

Web of Science

1.Xiamen Univ, Coll Environm & Ecol, Key Lab Coastal & Wetland Ecosyst, Xiamen, Peoples R China
2.Xiamen Univ, State Key Lab Marine Environm Sci, Xiamen, Peoples R China
3.Southern Univ Sci & Technol, Sch Environm Sci & Engn, State Environm Protect Key Lab Integrated Surface, Shenzhen, Peoples R China
4.Xiamen Univ, Natl Observat & Res Stn Taiwan Strait Marine Ecosy, Zhangzhou, Peoples R China

Lu, Zeyang,Wang, Fenfang,Xiao, Kai,et al. Carbon dynamics and greenhouse gas outgassing in an estuarine mangrove wetland with high input of riverine nitrogen[J]. BIOGEOCHEMISTRY,2022.

Lu, Zeyang.,Wang, Fenfang.,Xiao, Kai.,Wang, Yao.,Yu, Qibiao.,...&Chen, Nengwang.(2022).Carbon dynamics and greenhouse gas outgassing in an estuarine mangrove wetland with high input of riverine nitrogen.BIOGEOCHEMISTRY.

Lu, Zeyang,et al."Carbon dynamics and greenhouse gas outgassing in an estuarine mangrove wetland with high input of riverine nitrogen".BIOGEOCHEMISTRY (2022).