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

作　　者：Xiaogang Chen Jinzhou Du Xueqing Yu Xiaoxiong Wang 

机构地区：[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

出　　处：《Acta Oceanologica Sinica》2021年第8期32-43,共12页海洋学报（英文版）

基　　金：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。

摘　　要：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(^(222)Rn)mass balance model.The porewater exchange delivered 67 mmol/(m^(2)·d),38 mmol/(m^(2)·d)and 2690 mmol/(m^(2)·d)of dissolved inorganic nitrogen(DIN),dissolved silicon(DSi)and DIC into the coastal waters,respectively.The dominant species of porewater DIN was 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(160–3995),indicating that the porewater exchange process may change the nutrient characteristics of the Changjiang River Estuary and further alter the coastal ecological environment.

关 键 词：porewater exchange coastal wetlands saltwater intrusion nitrogen cycle blue carbon Changjiang River Estuary 

分 类 号：X171.1[环境科学与工程—环境科学]