Assessing the Impacts of Reservoirs on Riverine Dissolved Organic Matter: Insights From the Largest Reservoir in the Pearl River

Yi, Yuanbi1,2,3,4; Li, Si-Liang1; Zhong, Jun1; Wang, Kai5; Merder, Julian6; Bao, Hongyan7; Qi, Yulin1; He, Ding2,3,8; Xu, Sheng1; Dittmar, Thorsten4,9; Liu, Cong-Qiang1,10

2024-08-01

10.1029/2024JG008199

JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES   影响因子和分区

2169-8953

2169-8961

["Extensive reservoir construction has fragmented more than 70% of the world's rivers, significantly impacting river connectivity and carbon cycling. However, the response of riverine dissolved organic matter (DOM) to reservoir influence and its potential downstream effects remains unclear. In this study, we employed multiple analytical techniques, including Fourier transform ion cyclotron resonance mass spectrometry, radiocarbon dating, and environmental factor analysis, to investigate the dynamic changes in DOM and its controlling factors under different hydrological management regimes in the LongTan Reservoir, the largest reservoir in the Pearl River, which is the second largest river in China by water discharge. Our results indicate that the molecular diversity of riverine DOM is reduced in the reservoir. Oxygen-rich and heteroatomic compounds, such as those containing nitrogen, sulfur, and phosphorus, are preferentially removed through enhanced photo- and biodegradation processes in the reservoir, particularly during the storage period. This leads to DOM that is enriched with oxygen-poor compounds and shows a biodegraded Delta 14C value downstream. This study highlights that the composition of riverine DOM is significantly altered by the reservoir, but these effects could potentially be mitigated by optimizing the outlet location.","The construction of dams has significantly impacted rivers worldwide, fragmenting them and disrupting the flow of water and carbon. To understand how substances in rivers, particularly dissolved organic matter (DOM), are affected by dams and their potential impact on downstream ecosystems, we studied changes in DOM and the factors controlling these changes in the largest reservoir on the Pearl River in China, the second largest river in the country by water discharge. We found that certain compounds, such as those containing nitrogen, sulfur, and phosphorus, are preferentially removed by natural processes in the reservoir. This phenomenon results in DOM with persistent properties that hinder its participation in downstream biogeochemical processes. Although the reservoir significantly alters riverine DOM, our results suggest that the impact of the reservoir could be mitigated by optimizing the water outlet location.","Primary production and degradation processes in the river will be significantly enhanced by the reservoir The reservoir will preferentially remove oxygen-rich and heteroatomic compounds in the river The impact of the reservoir on downstream systems is potentially controlled by establishing an ideal outlet location"]

DOM FT-ICR MS radiocarbon river-reservoir system hydrological management

SCI

英语

其他

National Natural Science Foundation of China["41925002","42230509"] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB40000000] ; National Key R&D Program of China[2016YFA0601002] ; Research Grants Council of Hong Kong[ECS26300822]

Environmental Sciences & Ecology ; Geology

Environmental Sciences ; Geosciences, Multidisciplinary

WOS:001283731900001

AMER GEOPHYSICAL UNION

Web of Science

1.Tianjin Univ, Inst Surface Earth Syst Sci, Sch Earth Syst Sci, Tianjin, Peoples R China
2.Hong Kong Univ Sci & Technol, Dept Ocean Sci, Hong Kong, Peoples R China
3.Hong Kong Univ Sci & Technol, Ctr Ocean Res Hong Kong & Macau, Hong Kong, Peoples R China
4.Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm, ICBM MPI Bridging Grp Marine Geochem, Oldenburg, Germany
5.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China
6.Carnegie Inst Sci, Dept Global Ecol, Stanford, CA USA
7.Xiamen Univ, Coll Ocean & Earth Sci, State Key Lab Marine Environm Sci, Xiamen, Peoples R China
8.City Univ Hong Kong, State Key Lab Marine Pollut, Hong Kong, Peoples R China
9.Carl von Ossietzky Univ Oldenburg, Helmholtz Inst Funct Marine Biodivers, Oldenburg, Germany
10.Haihe Lab Sustainable Chem Transformat, Tianjin, Peoples R China

Yi, Yuanbi,Li, Si-Liang,Zhong, Jun,et al. Assessing the Impacts of Reservoirs on Riverine Dissolved Organic Matter: Insights From the Largest Reservoir in the Pearl River[J]. JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,2024,129(8).

Yi, Yuanbi.,Li, Si-Liang.,Zhong, Jun.,Wang, Kai.,Merder, Julian.,...&Liu, Cong-Qiang.(2024).Assessing the Impacts of Reservoirs on Riverine Dissolved Organic Matter: Insights From the Largest Reservoir in the Pearl River.JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,129(8).

Yi, Yuanbi,et al."Assessing the Impacts of Reservoirs on Riverine Dissolved Organic Matter: Insights From the Largest Reservoir in the Pearl River".JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 129.8(2024).