Instability in a carbon pool driven by multiple dissolved organic matter sources in a eutrophic lake basin: Potential factors for increased greenhouse gas emissions

Jie Ma; Muchun Zhou; Yu Peng; Ya Tuo; Chuanqiao Zhou; Kexin Liu; Yilin Huang; Fei He; Qiuying Lai; Zhihui Zhang; Tsuyoshi Kinouchi; Shuyin Li; Xiaoguang Xu; Xiaodong Wu; Xiaowen Lin; Weixin Li; Guoxiang Wang

doi:10.1016/j.jenvman.2023.119697

Instability in a carbon pool driven by multiple dissolved organic matter sources in a eutrophic lake basin: Potential factors for increased greenhouse gas emissions

J Environ Manage. 2024 Jan 15:350:119697. doi: 10.1016/j.jenvman.2023.119697. Epub 2023 Nov 29.

Authors

Jie Ma¹, Muchun Zhou², Yu Peng³, Ya Tuo⁴, Chuanqiao Zhou⁵, Kexin Liu³, Yilin Huang³, Fei He⁶, Qiuying Lai¹, Zhihui Zhang⁷, Tsuyoshi Kinouchi³, Shuyin Li⁸, Xiaoguang Xu⁷, Xiaodong Wu⁹, Xiaowen Lin⁹, Weixin Li¹, Guoxiang Wang⁷

Affiliations

¹ Ministry of Ecology and Environment, Nanjing Institute of Environment Sciences, Nanjing, 210042, China.
² Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, Tokyo, 184-8588, Japan.
³ Department of Transdisciplinary Science and Engineering, Tokyo Institute of Technology, Tokyo, 152-8550, Japan.
⁴ Environmental Development Center of the Ministry of Ecology and Environment, Beijing, 100029, China.
⁵ Department of Transdisciplinary Science and Engineering, Tokyo Institute of Technology, Tokyo, 152-8550, Japan. Electronic address: chuanqiaozhou@163.com.
⁶ Ministry of Ecology and Environment, Nanjing Institute of Environment Sciences, Nanjing, 210042, China. Electronic address: hefei@nies.org.
⁷ School of Environment, Nanjing Normal University, Nanjing, 210023, China.
⁸ Department of Transdisciplinary Science and Engineering, Tokyo Institute of Technology, Tokyo, 152-8550, Japan; Yangtze River Basin Ecological Environment Monitoring and Scientific Research Center, Yangtze River Basin Ecological Environment Supervision and Administration Bureau, Ministry of Ecological Environment, Wuhan, 430010, China.
⁹ College of Urban and Environmental Sciences, Hubei Normal University, Huangshi, 435002, China.

PMID: 38035504
DOI: 10.1016/j.jenvman.2023.119697

Abstract

Lakes serve as vital reservoirs of dissolved organic matter (DOM) and play pivotal roles in biogeochemical carbon cycles. However, the sources and compositions of DOM in freshwater lakes and their potential effects on lake sediment carbon pools remain unclear. In this study, seven inflowing rivers in the Lake Taihu basin were selected to explore the potential effects of multi-source DOM inputs on the stability of the lake sediment carbon pool. The results showed the high concentrations of dissolved organic carbon in the Lake Taihu basin, accompanied by a high complexity level. Lignins constituted the majority of DOM compounds, surpassing 40% of the total, while the organic carbon content was predominantly composed of humic acids (1.02-3.01 g kg^-1). The high amounts of lignin oxidative cleavage led to CHO being the main molecular structure in the DOM of the seven rivers. The carbon constituents within the sediment carbon reservoir exhibited a positive correlation with dissolved CH₄ and CO₂, with a notable emphasis on humic acid and dissolved CH₄ (R² = 0.86). The elevated concentration of DOM, coupled with its intricate composition, contributed to the increases in dissolved greenhouse gases (GHGs). Experiments showed that the mixing of multi-source DOM can accelerate the organic carbon mineralization processes. The unit carbon emission efficiency was highest in the mixed group, reaching reached 160.9 μmol∙C_g^-1, which also exhibited a significantly different carbon pool. The mixed decomposition of DOM from different sources influenced the roles of the lake carbon pool as source and sink, indicating that the multi-source DOM of this lake basin was a potential driving factor for increased carbon emissions. These findings have improved our understanding of the sources and compositions of DOM in lake basins and revealed their impacts on carbon emissions, thereby providing a theoretical basis for improving assessments of lake carbon emissions.

Keywords: Carbon pool; Dissolved organic matter; Eutrophication; FT-ICR-MS; Greenhouse gas emissions.

MeSH terms

Carbon
China
Dissolved Organic Matter*
Greenhouse Gases*
Humic Substances / analysis
Lakes / analysis
Lakes / chemistry
Rivers

Substances

Dissolved Organic Matter
Greenhouse Gases
Carbon
Humic Substances