Driving force of tidal pulses on denitrifiers-dominated nitrogen oxide emissions from intertidal wetland sediments

Jiang-Chen Gong; Bing-Han Li; Jing-Wen Hu; Pei-Feng Li; Qian Liu; Gui-Peng Yang; Chun-Ying Liu

doi:10.1016/j.watres.2023.120770

Driving force of tidal pulses on denitrifiers-dominated nitrogen oxide emissions from intertidal wetland sediments

Water Res. 2023 Dec 1:247:120770. doi: 10.1016/j.watres.2023.120770. Epub 2023 Oct 21.

Authors

Jiang-Chen Gong¹, Bing-Han Li¹, Jing-Wen Hu², Pei-Feng Li², Qian Liu², Gui-Peng Yang³, Chun-Ying Liu⁴

Affiliations

¹ Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
² Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
³ Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China. Electronic address: gpyang@mail.ouc.edu.cn.
⁴ Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China. Electronic address: roseliu@ouc.edu.cn.

PMID: 37897991
DOI: 10.1016/j.watres.2023.120770

Abstract

Intertidal wetland sediments are an important source of atmospheric nitrogen oxides (NO_x), but their contribution to the global NO_x budget remains unclear. In this work, we conducted year-round and diurnal observations in the intertidal wetland of Jiaozhou Bay to explore their regional source-sink patterns and influence factors on NO_x emissions (initially in the form of nitric oxide) and used a dynamic soil reactor to further extend the mechanisms underlying the tidal pulse of nitric oxide (NO) observed in our investigations. The annual fluxes of NO_x in the vegetated wetland were significantly higher than those in the wetland without vegetation. Their annual variations could be attributed to changes in temperature and the amount of organic carbon in the sediment, which was derived from vegetated plants and promoted the carbon-nitrogen cycle. Anaerobic denitrifiers had advantages in the intertidal wetland sediment and accounted for the major NO production (63.8 %) but were still limited by nitrite and nitrate concentrations in the sediment. Moreover, the tidal pulse was likely a primary driver of NO_x emissions from intertidal wetlands over short periods, which was not considered in previous investigations. The annual NO exchange flux considering the tide pulse contribution (8.93 ± 1.72 × 10^-2 kg N ha^-1 yr^-1) was significantly higher than that of the non-pulse period (4.14 ± 1.13 × 10^-2 kg N ha^-1 yr^-1) in our modeling result for the fluxes over the last decade. Therefore, the current measurement of NO_x fluxes underestimated the actual gas emission without considering the tidal pulse.

Keywords: Denitrification; Flux; Nitric oxide; Nitrogen oxides; Tides.

MeSH terms

Carbon
Nitric Oxide*
Nitrogen
Nitrogen Cycle
Nitrogen Oxides
Wetlands*

Substances

Nitric Oxide
Nitrogen Oxides
Nitrogen
Carbon