Porewater-derived dissolved inorganic carbon and nutrient fluxes in a saltmarsh of the Changjiang River Estuary

Xiaogang Chen; Jinzhou Du; Xueqing Yu; Xiaoxiong Wang

doi:10.1007/s13131-021-1797-z

Volume 40 Issue 8

Aug. 2021

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Xiaogang Chen, Jinzhou Du, Xueqing Yu, Xiaoxiong Wang. Porewater-derived dissolved inorganic carbon and nutrient fluxes in a saltmarsh of the Changjiang River Estuary[J]. Acta Oceanologica Sinica, 2021, 40(8): 32-43. doi: 10.1007/s13131-021-1797-z

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Xiaogang Chen, Jinzhou Du, Xueqing Yu, Xiaoxiong Wang. Porewater-derived dissolved inorganic carbon and nutrient fluxes in a saltmarsh of the Changjiang River Estuary[J]. Acta Oceanologica Sinica, 2021, 40(8): 32-43. doi: 10.1007/s13131-021-1797-z

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Porewater-derived dissolved inorganic carbon and nutrient fluxes in a saltmarsh of the Changjiang River Estuary

doi: 10.1007/s13131-021-1797-z

Xiaogang Chen^{1, 2, 3},
Jinzhou Du^{1, 4
,
,},
Xueqing Yu¹,
Xiaoxiong Wang¹

1.
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
2.
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310024, China
3.
Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou 310024, China
4.
Institute of Eco-Chongming (IEC), Shanghai 202162, China

Funds: The Natural Science Foundation of Shanghai under contract No. 19ZR1415300; the Zhejiang Provincial Natural Science Foundation of China under contract No. LQ21D060005; the China Postdoctoral Science Foundation under contract No. 2020M681931.

More Information

Corresponding author: Jinzhou Du E-mail address: jzdu@sklec.ecnu.edu.cn
Received Date: 2020-05-27
Accepted Date: 2020-07-30

Available Online: 2021-07-08

Publish Date: 2021-08-31

Abstract

Abstract

Saltmarshes are one of the most productive ecosystems, which contribute significantly to coastal nutrient and carbon budgets. However, limited information is available on soil nutrient and carbon losses via porewater exchange in saltmarshes. Here, porewater exchange and associated fluxes of nutrients and dissolved inorganic carbon (DIC) in the largest saltmarsh wetland (Chongming Dongtan) in the Changjiang River Estuary were quantified. Porewater exchange rate was estimated to be (37±35) cm/d during December 2017 using a radon (²²²Rn) mass balance model. The porewater exchange delivered 67 mmol/(m²·d), 38 mmol/(m²·d) and 2 690 mmol/(m²·d) of dissolved inorganic nitrogen (DIN), dissolved silicon (DSi) and DIC into the coastal waters, respectively. The dominant species of porewater DIN was ${\rm {NH}}_4^+ $ (>99% of DIN). However, different with those in other ecosystems, the dissolved inorganic phosphorus (DIP) concentration in saltmarsh porewater was significantly lower than that in surface water, indicating that saltmarshes seem to be a DIP sink in Chongming Dongtan. The porewater-derived DIN, DSi and DIC accounted for 12%, 5% and 18% of the riverine inputs, which are important components of coastal nutrient and carbon budgets. Furthermore, porewater-drived nutrients had obviously high N/P ratios (160–3 995), indicating that the porewater exchange process may change the nutrient characteristics of the Changjiang River Estuary and further alter the coastal ecological environment.
- porewater exchange,
- coastal wetlands,
- saltwater intrusion,
- nitrogen cycle,
- blue carbon,
- Changjiang River Estuary

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References(107)

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