Carbon fluxes of China's coastal wetlands and impacts of reclamation and restoration

Weizhi Lu; Jingfeng Xiao; Haiqiang Gao; Qingyu Jia; Zhengjie Li; Jie Liang; Qinghui Xing; Dehua Mao; Hong Li; Xiaojing Chu; Hui Chen; Haiqiang Guo; Guangxuan Han; Bin Zhao; Luzhen Chen; Derrick Y F Lai; Shuguang Liu; Guanghui Lin

doi:10.1111/gcb.17280

Carbon fluxes of China's coastal wetlands and impacts of reclamation and restoration

Glob Chang Biol. 2024 Apr;30(4):e17280. doi: 10.1111/gcb.17280.

Authors

Weizhi Lu^{1

2}, Jingfeng Xiao³, Haiqiang Gao^{1

2}, Qingyu Jia⁴, Zhengjie Li^{1

2}, Jie Liang⁵, Qinghui Xing⁶, Dehua Mao⁷, Hong Li⁸, Xiaojing Chu⁹, Hui Chen¹⁰, Haiqiang Guo⁸, Guangxuan Han⁹, Bin Zhao⁸, Luzhen Chen¹¹, Derrick Y F Lai¹², Shuguang Liu^{1

2}, Guanghui Lin^{5

13

14}

Affiliations

¹ College of the Life and Environment Science, Central South University of Forestry and Technology, Changsha, China.
² National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha, China.
³ Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USA.
⁴ Institute of Atmospheric Environment, China Meteorological Administration, Shenyang, China.
⁵ Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, China.
⁶ Key Laboratory for Ecological Environment in Coastal Areas, National Marine Environmental Monitoring Center, Dalian, China.
⁷ State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China.
⁸ National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, and Institute of Eco-Chongming (IEC), Fudan University, Shanghai, China.
⁹ Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
¹⁰ College of Life Science, Yangtze University, Jingzhou, China.
¹¹ Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China.
¹² Department of Geography and Resource Management, and Centre for Environmental Policy and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
¹³ Institute of Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
¹⁴ Hainan International Blue Carbon Research Center, Hainan Research Academy of Environmental Sciences, Haikou, China.

PMID: 38613249
DOI: 10.1111/gcb.17280

Abstract

Coastal wetlands play an important role in regulating atmospheric carbon dioxide (CO₂) concentrations and contribute significantly to climate change mitigation. However, climate change, reclamation, and restoration have been causing substantial changes in coastal wetland areas and carbon exchange in China during recent decades. Here we compiled a carbon flux database consisting of 15 coastal wetland sites to assess the magnitude, patterns, and drivers of carbon fluxes and to compare fluxes among contrasting natural, disturbed, and restored wetlands. The natural coastal wetlands have the average net ecosystem exchange of CO₂ (NEE) of -577 g C m^-2 year^-1, with -821 g C m^-2 year^-1 for mangrove forests and -430 g C m^-2 year^-1 for salt marshes. There are pronounced latitudinal patterns for carbon dioxide exchange of natural coastal wetlands: NEE increased whereas gross primary production (GPP) and respiration of ecosystem decreased with increasing latitude. Distinct environmental factors drive annual variations of GPP between mangroves and salt marshes; temperature was the dominant controlling factor in salt marshes, while temperature, precipitation, and solar radiation were co-dominant in mangroves. Meanwhile, both anthropogenic reclamation and restoration had substantial effects on coastal wetland carbon fluxes, and the effect of the anthropogenic perturbation in mangroves was more extensive than that in salt marshes. Furthermore, from 1980 to 2020, anthropogenic reclamation of China's coastal wetlands caused a carbon loss of ~3720 Gg C, while the mangrove restoration project during the period of 2021-2025 may switch restored coastal wetlands from a carbon source to carbon sink with a net carbon gain of 73 Gg C. The comparison of carbon fluxes among these coastal wetlands can improve our understanding of how anthropogenic perturbation can affect the potentials of coastal blue carbon in China, which has implications for informing conservation and restoration strategies and efforts of coastal wetlands.

Keywords: blue carbon; carbon budget; carbon dioxide flux; coastal wetland; land‐use change; reclamation; restoration.

MeSH terms

Carbon Cycle
Carbon Dioxide
China
Ecosystem*
Wetlands*

Substances

Carbon Dioxide

Abstract

MeSH terms

Substances

Grants and funding