Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange

Xiao, Kai1; Wu, Jiapeng2; Li, Hailong3; Hong, Yiguo4; Wilson, Alicia M.5; Jiao, Jiu Jimmy6; Shananan, Meghan5

2018-09

10.1016/j.scitotenv.2018.04.143

SCIENCE OF THE TOTAL ENVIRONMENT   影响因子和分区

0048-9697

1879-1026

Coastal mangrove swamps play an important role in nutrient cycling at the land-ocean boundary. However, little is known about the role of periodic seawater-groundwater exchange in the nitrogen cycling processes. Seawatergroundwater exchange rates and inorganic nitrogen concentrations were investigated along a shore-perpendicular intertidal transect in Daya Bay, China. The intertidal transect comprises three hydrologic subzones (tidal creek, mangrove and bare mudflat zones), each with different physicochemical characteristics. Salinity and hydraulic head measurements taken along the transect were used to estimate the exchange rates between seawater and groundwater over a spring-neap tidal cycle. Results showed that the maximum seawater-groundwater exchange occurred within the tidal creek zone, which facilitated high-oxygen seawater infiltration and subsequent nitrification. In contrast, the lowest exchange rate found in the mangrove zone caused over-loading of organic matter and longer groundwater residence times. This created an anoxic environment conducive to nitrogen loss through the anammox and denitrification processes. Potential oxidation rates of ammonia and nitrite were measured by the rapid and high-throughput method and rates of denitrification and anammox were measured by the modified membrane inlet mass spectrometry (MIMS) with isotope pairing, respectively. In the whole transect, denitrification accounted for 90% of the total nitrogen loss, and anammox accounted for the remaining 10%. The average nitrogen removal rate was about 2.07 g per day per cubic meter of mangrove sediments. (C) 2018 Elsevier B.V. All rights reserved.

Coastal wetlands Hydrodynamic circulation Microbial activity Nitrogen cycle Daya Bay

SCI ; EI

英语

通讯

Research Foundation for Talented Scholars of Guangzhou University[GU2017001]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000436494400057

ELSEVIER SCIENCE BV

20181705038377

Denitrification ; Finance ; Groundwater ; Mass spectrometry ; Seawater ; Wastewater treatment ; Wetlands

Groundwater:444.2 ; Industrial Wastes Treatment and Disposal:452.4 ; Seawater, Tides and Waves:471.4 ; Chemistry:801 ; Chemical Reactions:802.2

ENVIRONMENT/ECOLOGY

Web of Science

1.China Univ Geosci, Sch Water Resources & Environm Sci, State Key Lab Biogeol & Environm Geol, Beijing 100083, Peoples R China
2.Chinese Acad Sci, South China Sea Inst Oceanol, State Key Lab Trop Oceanog, Guangzhou 100083, Guangdong, Peoples R China
3.South Univ Sci & Technol China, Sch Environm Sci & Engn, Key Lab Soil & Groundwater Pollut Control Shenzhe, Shenzhen 518055, Peoples R China
4.Univ Guangzhou, Sch Environm Sci & Engn, Guangzhou 510006, Guangdong, Peoples R China
5.Univ South Carolina, Sch Earth Ocean & Environm, Columbia, SC 29208 USA
6.Univ Hong Kong, Dept Earth Sci, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China

Xiao, Kai,Wu, Jiapeng,Li, Hailong,et al. Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2018,635:586-597.

Xiao, Kai.,Wu, Jiapeng.,Li, Hailong.,Hong, Yiguo.,Wilson, Alicia M..,...&Shananan, Meghan.(2018).Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange.SCIENCE OF THE TOTAL ENVIRONMENT,635,586-597.

Xiao, Kai,et al."Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange".SCIENCE OF THE TOTAL ENVIRONMENT 635(2018):586-597.