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Jiang N, Sun W, Chen Z, Xiong X, Wang Y, Zeng S. Assessment of carbon flux gradients and dominant processes in a subtropical highly urbanized coastal ecosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 952:175855. [PMID: 39214352 DOI: 10.1016/j.scitotenv.2024.175855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 08/21/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
Highly urbanized coastal ecosystems are vital in the global carbon budget. However, there are limited researches on carbon flux gradients in these nearshore areas, considering both natural and anthropogenic influences. Through on-site measurements and field samplings during wet-to-dry season in 2023, this study investigated spatial variations and factors affecting carbon fluxes, focusing on the impacts of salinity and eutrophic status in five geographically connected coastal waters of the Guangdong-Hong Kong-Macau Greater Bay Area (GBA). By estimating carbon exchange at land-sea-air interface, dominant processes in carbon dynamics were identified as well. Results showed that partial pressure of CO2 (pCO2) varied from 391 to 2290 μatm, and sea-air CO2 exchange fluxes (FCO2) ranged from -3.07 to 70.07 mmol m-2 d-1, indicating significant geographical distinctions among five coastal waters of the GBA. The total carbon transport from rivers to these nearshore waters was approximated at 6.44 Tg C yr-1, with the Pearl River (PR) contributing 99.7%, primarily in dissolved forms. Atmospheric CO2 release was calculated at 0.29 Tg C yr-1 for studied five coastal waters, primarily as carbon sources, except for Dapeng Bay (DPB) as a sink. CO2 emissions inversely correlated with salinity, yet positively with eutrophication status, particularly in river-dominated estuaries. Moreover, CO2 flux decreased 23 times as eco-status shift from eutrophic to non-eutrophic. River plumes, terrestrial pollutant inputs, and economic structure were underlying drivers, influencing carbon species concentrations and fluxes. Elevated CO2 concentrations in eutrophic coastal waters were mainly attributed to terrestrial carbon and nutrients inputs, supporting active biological respiration and microbial decomposition. Conversely, carbon dynamics potentially depend on the balance of respiration and photosynthesis in non-eutrophic coastal waters. This study offers high geographic precision and specificity of carbon species, and provides land-sea integration insight to understand carbon dynamic mechanisms, promoting advancements in water quality management and climate mitigation.
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Affiliation(s)
- Ni Jiang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenjun Sun
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen 518049, China
| | - Zhonghan Chen
- State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Xiangyun Xiong
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen 518049, China
| | - Yudong Wang
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen 518049, China
| | - Siyu Zeng
- School of Environment, Tsinghua University, Beijing 100084, China.
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Ho L, Barthel M, Pham K, Bodé S, Van Colen C, Moens T, Six J, Boeckx P, Goethals P. Regulating greenhouse gas dynamics in tidal wetlands: Impacts of salinity gradients and water pollution. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 364:121427. [PMID: 38870790 DOI: 10.1016/j.jenvman.2024.121427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/22/2024] [Accepted: 06/07/2024] [Indexed: 06/15/2024]
Abstract
Tidal wetlands play a critical role in emitting greenhouse gases (GHGs) into the atmosphere; our understanding of the intricate interplay between natural processes and human activities shaping their biogeochemistry and GHG emissions remains lacking. In this study, we delve into the spatiotemporal dynamics and key drivers of the GHG emissions from five tidal wetlands in the Scheldt Estuary by focusing on the interactive impacts of salinity and water pollution, two factors exhibiting contrasting gradients in this estuarine system: pollution escalates as salinity declines. Our findings reveal a marked escalation in GHG emissions when moving upstream, primarily attributed to increased concentrations of organic matter and nutrients, coupled with reduced levels of dissolved oxygen and pH. These low water quality conditions not only promote methanogenesis and denitrification to produce CH4 and N2O, respectively, but also shift the carbonate equilibria towards releasing more CO2. As a result, the most upstream freshwater wetland was the largest GHG emitter with a global warming potential around 35 to 70 times higher than the other wetlands. When moving seaward along a gradient of decreasing urbanization and increasing salinity, wetlands become less polluted and are characterized by lower concentrations of NO3-, TN and TOC, which induces stronger negative impact of elevated salinity on the GHG emissions from the saline wetlands. Consequently, these meso-to polyhaline wetlands released considerably smaller amounts of GHGs. These findings emphasize the importance of integrating management strategies, such as wetland restoration and pollution prevention, that address both natural salinity gradients and human-induced water pollution to effectively mitigate GHG emissions from tidal wetlands.
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Affiliation(s)
- Long Ho
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium.
| | - Matti Barthel
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Kim Pham
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Samuel Bodé
- Department of Green Chemistry and Technology, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Gent, Belgium
| | - Carl Van Colen
- Marine Biology Research Group, Ghent University, Krijgslaan 281/S8 9000, Gent, Belgium
| | - Tom Moens
- Marine Biology Research Group, Ghent University, Krijgslaan 281/S8 9000, Gent, Belgium
| | - Johan Six
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Pascal Boeckx
- Department of Green Chemistry and Technology, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Gent, Belgium
| | - Peter Goethals
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
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3
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Liu J, Lu B, Liu Y, Wang L, Liu F, Chen Y, Mustafa G, Qin Z, Lv C. Role of BP-ANN in simulating greenhouse gas emissions from global aquatic ecosystems via carbon component-environmental factor coupling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172722. [PMID: 38677441 DOI: 10.1016/j.scitotenv.2024.172722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/17/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Inland waters (IW), estuarine areas (EA), and offshore areas (OA) function as aquatic systems in which the transport of carbon components results in the release of greenhouse gases (GHGs). Interconnected subsystems exhibit a greater greenhouse effect than individual systems. Despite this, there is a lack of research on how carbon loading and its components impact GHG emissions in various aquatic systems. In this study, we analyzed 430 aquatic sites to explore trade-off mechanisms among dissolved organic carbon (DOC), particulate organic carbon, dissolved inorganic carbon (DIC), and GHGs. The results revealed that IW emerged as the most significant GHG source, possessing a comprehensive global warming potential (GWP) of 0.78 ± 0.08 (10-2 Pg CO2-ep ha-1 year-1) for combined carbon dioxide, methane, and nitrous oxide. This surpassed the cumulative potentials of EA and OA (0.35 ± 0.05 (10-2 Pg CO2-ep ha-1 year-1)). Additionally, structural equation modeling indicated that GHG emissions resulted from a combination of carbon component loading and environmental factors. DOC exhibited a positive correlation with GWPs when influenced by biodegradable DOC. Total alkalinity and pH influenced DIC, leading to elevated pCO2 in aquatic systems, thereby enhancing GWPs. Predictive modeling using backpropagation artificial neural networks (BP-ANN) for GWPs, incorporating carbon components and environmental factors, demonstrated a good fit (R2 = 0.6078, RMSEaverage = 0.069, p > 0.05) between observed and predicted values. Enhancing the estimation of aquatic region feedback to GHG changes was achieved by incorporating corresponding water quality parameters. In summary, this study underscores the pivotal role of carbon components and environmental factors in aquatic regions for GHG emissions. The application of BP-ANN to estimate greenhouse effects from aquatic regions is highlighted, providing theoretical and experimental support for future advancements in monitoring and developing policies concerning the influence of water quality on GHG emissions.
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Affiliation(s)
- Jiayuan Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Bianhe Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yuhong Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Lixin Wang
- College of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Fude Liu
- Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling Technology, School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China.
| | - Yixue Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Ghulam Mustafa
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Zhirui Qin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Chaoqun Lv
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Iowa 50011, USA
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Yeo JZQ, Rosentreter JA, Oakes JM, Schulz KG, Eyre BD. High carbon dioxide emissions from Australian estuaries driven by geomorphology and climate. Nat Commun 2024; 15:3967. [PMID: 38730255 PMCID: PMC11087516 DOI: 10.1038/s41467-024-48178-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
Estuaries play an important role in connecting the global carbon cycle across the land-to-ocean continuum, but little is known about Australia's contribution to global CO2 emissions. Here we present an Australia-wide assessment, based on CO2 concentrations for 47 estuaries upscaled to 971 assessed Australian estuaries. We estimate total mean (±SE) estuary CO2 emissions of 8.67 ± 0.54 Tg CO2-C yr-1, with tidal systems, lagoons, and small deltas contributing 94.4%, 3.1%, and 2.5%, respectively. Although higher disturbance increased water-air CO2 fluxes, its effect on total Australian estuarine CO2 emissions was small due to the large surface areas of low and moderately disturbed tidal systems. Mean water-air CO2 fluxes from Australian small deltas and tidal systems were higher than from global estuaries because of the dominance of macrotidal subtropical and tropical systems in Australia, which have higher emissions due to lateral inputs. We suggest that global estuarine CO2 emissions should be upscaled based on geomorphology, but should also consider land-use disturbance, and climate.
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Affiliation(s)
- Jacob Z-Q Yeo
- Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia.
| | - Judith A Rosentreter
- Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia
| | - Joanne M Oakes
- Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia
| | - Kai G Schulz
- Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia
| | - Bradley D Eyre
- Centre for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, PO Box 157, East Lismore, NSW, 2480, Australia
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5
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Fan L, Cheng J, Xie Y, Xu L, Buttler A, Wu Y, Fan H, Wu Y. Spatio-temporal patterns and drivers of CH 4 and CO 2 fluxes from rivers and lakes in highly urbanized areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170689. [PMID: 38320709 DOI: 10.1016/j.scitotenv.2024.170689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 01/25/2024] [Accepted: 02/02/2024] [Indexed: 02/13/2024]
Abstract
Gaseous carbon exchange at the water-air interface of rivers and lakes is an essential process for regional and global carbon cycle assessments. Many studies have shown that rivers surrounding urban landscapes can be hotspots for greenhouse gas (GHG) emissions. Here we investigated the variability of diffusive GHG (methane [CH4] and carbon dioxide [CO2]) emissions from rivers in different landscapes (i.e., urban, agricultural and mixed) and from lakes in Suzhou, a highly urbanized region in eastern China. GHG emissions in the Suzhou metropolitan water network followed a typical seasonal pattern, with the highest fluxes in summer, and were primarily influenced by temperature and dissolved oxygen concentration. Surprisingly, lakes were emission hotspots, with mean CH4 and CO2 fluxes of 2.80 and 128.89 mg m-2 h-1, respectively, translating to a total CO2-equivalent flux of 0.21 g CO2-eq m-2 d-1. The global warming potential of urban and mixed rivers (0.19 g CO2-eq m-2 d-1) was comparable to that for lakes, but about twice the value for agricultural rivers (0.10 g CO2-eq m-2 d-1). Factors related to the high GHG emissions in lakes included hypoxic water conditions and an adequate nutrient supply. Riverine CH4 emissions were primarily associated with the concentrations of total dissolved solids (TDS), ammonia‑nitrogen and chlorophyll a. CO2 emissions in rivers were mainly closely related to TDS, with suitable conditions allowing rapid organic matter decomposition. Compared with other types of rivers, urban rivers had more available organic matter and therefore higher CO2 emissions. Overall, this study emphasizes the need for a deeper understanding of the impact of GHG emissions from different water types on global warming in rapidly urbanizing regions. Flexible management measures are urgently needed to mitigate CO2 and CH4 emissions more effectively in the context of the shrinking gap between urban and rural areas with growing socio-economic development.
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Affiliation(s)
- Longfeng Fan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Junxiang Cheng
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; Jiangxi Research Academy of Ecological Civilization, Nanchang 330036, PR China.
| | - Yangcun Xie
- Chinese Academy of Environmental Planning, Beijing 100043, PR China.
| | - Ligang Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Nanjing, Nanjing 211135, PR China
| | - Alexandre Buttler
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federal of Lausanne (EPFL), Station 2, CH-1015 Lausanne, Switzerland; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Site Lausanne, Station 2, CH-1015 Lausanne, Switzerland
| | - Yuexia Wu
- School of Business Administration, Nanjing University of Finance & Economics, Nanjing 210023, PR China
| | - Hongxiang Fan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Yakun Wu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; School of Energy and Environment, Anhui University of Technology, Ma'anshan 243002, PR China
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6
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Zhang J, Cao L, Liu Z, Wan L, Cao X, Zhou Y, Song C. Relationship between eutrophication and greenhouse gases emission in shallow freshwater lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 925:171610. [PMID: 38462007 DOI: 10.1016/j.scitotenv.2024.171610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 03/12/2024]
Abstract
In shallow lakes, there are complex relationships between lake eutrophication and greenhouse gas emissions that deserve to be studied, which are important for solving lake eutrophication, slowing down climate warming, and reducing carbon emissions. In order to explore the relationship and mechanism between eutrophication and greenhouse gases (GHGs), the net GHGs emission flux and transformation of carbon, and nitrogen in 45 shallow freshwater lakes were investigated from May to September 2022. Eutrophication facilitated potential denitrification rate (Dt) without increasing nitrous oxide (N2O) production based on the significantly positive relationship between eutrophication and Dt. This should be attributed to the shift from incomplete (N2O producing process) to complete denitrification (N2 producing process). Compared to NarG mediating nitrate (NO3-) to nitrite (NO2-), fewer eutrophication indicators showed a positive relationship with NosZ mediating N2O to N2, suggesting that more stringent conditions are required for complete denitrification, which was achieved in the lakes we investigated. Optimal reduction in net carbon dioxide (CO2) emissions occurs at high levels of primary productivity, as indicated by the V-shaped relationship between chlorophyll a (Chl a) and CO2 emissions. However, in hyper-eutrophic lakes, there is an upward trend in CO2 production. The possible explanations should include CO2 production and fixation as well as methane (CH4) oxidation. The bell-shaped relationship between the net flux of CH4 emission and Chl a could be explained that CH4 was heavily oxidized due to sufficient oxygen caused by algal bloom. This fact gave evidence for the increase of the net flux of CO2 emission in high primary productivity lakes. Therefore, the relationship and mechanism between net GHGs emission flux and eutrophication remained complex and various.
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Affiliation(s)
- Jingjie Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
| | - Lingfeng Cao
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China.
| | - Zhenghan Liu
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
| | - Lingling Wan
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China.
| | - Xiuyun Cao
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China.
| | - Yiyong Zhou
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China.
| | - Chunlei Song
- Institute of Hydrobiology, Chinese Academy of Sciences, 7# Donghu South Road, Wuhan 430072, China.
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7
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Qing Z, Wang X, Li X, Jian C, Yang Y, Zhou T, Liu T, Liu S, Huang Y, He Y. Urbanization and weather dynamics co-dominated the spatial-temporal variation in pCO 2 and CO 2 fluxes in small montanic rivers draining diverse landscapes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119884. [PMID: 38142598 DOI: 10.1016/j.jenvman.2023.119884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/29/2023] [Accepted: 12/17/2023] [Indexed: 12/26/2023]
Abstract
Rivers have been widely reported as important CO2 emitters to the atmosphere. Rapid urbanization has a profound impact on the carbon biogeochemical cycle of rivers, leading to enhanced riverine CO2 evasions. However, it is still unclear whether the spatial-temporal patterns of CO2 emissions in the rivers draining diverse landscapes dominated by urbanization were stable, especially in mountainous areas. This study carried out a two-year investigation of water environmental hydrochemistry in three small mountainous rivers draining urban, suburban and rural landscapes in southwestern China, and CO2 partial pressure (pCO2) and fluxes (fCO2) in surface water were measured using headspace equilibrium method and classical thin boundary layer model. The average pCO2 and fCO2 in the highly urbanized river were of 4783.6 μatm and 700.0 mmol m-2 d-1, conspicuously higher than those in the rural river (1525.9 μatm and 123.2 mmol m-2 d-1), and the suburban river presented a moderate level (3114.2 μatm and 261.2 mmol m-2 d-1). It provided even clearer evidence that watershed urbanization could remarkably enhance riverine CO2 emissions. More importantly, the three rivers presented different longitudinal variations in pCO2, implying diversified spatial patterns of riverine CO2 emissions as a result of urbanization. The urban land can explain 49.6-69.1% of the total spatial variation in pCO2 at the reach scale, indicating that urban land distribution indirectly dominated the longitudinal pattern of riverine pCO2 and fCO2. pCO2 and fCO2 in the three rivers showed similar temporal variability with higher warm-rainy seasons and lower dry seasons, which are significantly controlled by weather dynamics, including monthly temperature and precipitation, but seem to be impervious to watershed urbanization. High temperature-stimulated microorganisms metabolism and riched-CO2 runoff input lead much higher pCO2 in warm-rainy seasons. However, it showed more sensitivity of pCO2 to monthly weather dynamics in urbanized rivers than that in rural rivers, and warm-rainy seasons showed hot moments of CO2 evasion for urban rivers. TOC, DOC, TN, pH and DO were the main controls on pCO2 in the urban and suburban rivers, while only pH and DO were connected with pCO2 in the rural rivers. This indicated differential controls and regulatory processes of pCO2 in the rivers draining diverse landscapes. Furthermore, it suggested that pCO2 calculated by the pH-total alkalinity method would obviously overestimate pCO2 in urban polluted rivers due to the inevitable influence of non-carbonate alkalinity, and thus, a relatively conservative headspace method should be recommended. We highlighted that urbanization and weather dynamics co-dominated the multiformity and uncertainty in spatial-temporal patterns of riverine CO2 evasions, which should be considered when modeling CO2 dynamics in urbanized rivers.
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Affiliation(s)
- Zhaoyin Qing
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Xiaofeng Wang
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China.
| | - Xianxiang Li
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Chen Jian
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Yi Yang
- School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Ting Zhou
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Tingting Liu
- Chongqing Key Laboratory of Carbon cycel and Regulation in Mountatinous Ecosystems, Chongqing, 401331, China; State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241, China
| | - Shuangshuang Liu
- Chongqing Institute of Geology and Mineral Resources, Chongqing, 401120, China
| | - Yafang Huang
- School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Yixin He
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
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Zhang L, Xu YJ, Ma B, Jiang P, Li S. Intense methane diffusive emissions in eutrophic urban lakes, Central China. ENVIRONMENTAL RESEARCH 2023; 237:117073. [PMID: 37673122 DOI: 10.1016/j.envres.2023.117073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/19/2023] [Accepted: 09/03/2023] [Indexed: 09/08/2023]
Abstract
Urban lakes are hotspots of methane (CH4) emissions. Yet, actual field measurements of CH4 in these lakes are rather limited and our understanding of CH4 response to urban lake eutrophication is still incomplete. In this study, we measured dissolved CH4 concentrations and quantified CH4 diffusion from four urban lakes in subtropical China during wet and dry seasons. We found that these lakes were constantly CH4-saturated, contributing the greenhouse gas (GHG) to the atmosphere. Nutrient enrichment significantly increased CH4 concentrations and diffusive fluxes. Average CH4 flux rate in the highly-eutrophic lake zones (4.18 ± 7.68 mmol m-2 d-1) was significantly higher than those in the mesotrophic (0.19 ± 0.18 mmol m-2 d-1) and lightly/moderately-eutrophic zones (0.72 ± 2.22 mmol m-2 d-1). Seasonally, CH4 concentrations and fluxes were significantly higher in the wet season than in the dry season in the mesotrophic and the lightly/moderately-eutrophic lake zones, but an inverse pattern existed in the highly-eutrophic lake zones. CH4 concentrations and fluxes increased with elevated levels of nitrogen, phosphorus and dissolved organic carbon (DOC). The accumulation of nutrients provided autochthonous substrate for methanogenesis, indicated by a negative correlation between CH4 and the C:N ratio. Ammonium-nitrogen (NH4+-N) was the best predictor for spatial fluctuation of CH4 concentrations and diffusive fluxes in the mesotrophic and the lightly/moderately-eutrophic lake zones, while total nitrogen (TN) and total phosphorus (TP) levels showed the highest predictability in the highly-eutrophic lake zones. Based on the findings, we conclude that nutrient enrichment in urban lakes can largely increase CH4 diffusion, and that urban sewage inflow is a key concern for eutrophication boosting CH4 production and diffusive emission. Furthermore, our study reveals that small urban lakes may be an important missing source of GHG emissions in the global C accounting, and that the ratio of littoral-to-pelagic zones can be important for predicting lake-scale estimation of CH4 emission.
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Affiliation(s)
- Liuqing Zhang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China; School of Environmental Ecology and Biological Engineering, Institute of Changjiang Water Environment and Ecological Security, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan, 430205, China
| | - Y Jun Xu
- School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA; Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Bingjie Ma
- School of Environmental Ecology and Biological Engineering, Institute of Changjiang Water Environment and Ecological Security, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan, 430205, China
| | - Ping Jiang
- School of Environmental Ecology and Biological Engineering, Institute of Changjiang Water Environment and Ecological Security, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan, 430205, China
| | - Siyue Li
- School of Environmental Ecology and Biological Engineering, Institute of Changjiang Water Environment and Ecological Security, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan, 430205, China.
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9
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Ho L, Barthel M, Panique-Casso D, Vermeulen K, Bruneel S, Liu X, Bodé S, Six J, Boeckx P, Goethals P. Impact of salinity gradient, water pollution and land use types on greenhouse gas emissions from an urbanized estuary. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 336:122500. [PMID: 37669700 DOI: 10.1016/j.envpol.2023.122500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/25/2023] [Accepted: 08/31/2023] [Indexed: 09/07/2023]
Abstract
Estuaries have been recognized as one of the major sources of greenhouse gases (GHGs) in aquatic systems; yet we still lack insights into the impact of both anthropogenic and natural factors on the dynamics of GHG emissions. Here, we assessed the spatiotemporal dynamics and underlying drivers of the GHG emissions from the Scheldt Estuary with a focus on the effects of salinity gradient, water pollution, and land use types, together with their interaction. Overall, we found a negative impact of salinity on carbon dioxide (CO2) and nitrous oxide (N2O) emissions which can be due to the decrease of both salinity and water quality when moving upstream. Stronger impact of water pollution on the GHG emissions was found at the freshwater sites upstream compared to saline sites downstream. In particular, when water quality of the sites reduced from good, mainly located in the mouth and surrounded by arable sites, to polluted, mainly located in the upstream and surrounded by urban sites, CO2 emissions from the sites doubled while N2O emissions tripled. Similarly, the effects of water pollution on methane (CH4) emissions became much stronger in the freshwater sites compared to the saline sites. These decreasing effects from upstream to the mouth were associated with the increase in urbanization as sites surrounded by urban areas released on average almost two times more CO2 and N2O than sites surrounded by nature and industry areas. Applied machine learning methods also revealed that, in addition to salinity effects, nutrient and organic enrichment stimulated the GHG emissions from the Scheldt Estuary. These findings highlight the importance of the interaction between salinity, water pollution, and land use in order to understand their influences on GHG emissions from dynamic estuarine systems.
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Affiliation(s)
- Long Ho
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium.
| | - Matti Barthel
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Diego Panique-Casso
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Kaat Vermeulen
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Stijn Bruneel
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Xingzhen Liu
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Samuel Bodé
- Department of Green Chemistry and Technology, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Ghent, Belgium
| | - Johan Six
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Pascal Boeckx
- Department of Green Chemistry and Technology, Isotope Bioscience Laboratory - ISOFYS, Ghent University, Ghent, Belgium
| | - Peter Goethals
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Gent, Belgium
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10
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N RH, Tait DR, Nandan SB. Land use drives large CH 4 fluxes from a highly urbanized Indian estuary. MARINE POLLUTION BULLETIN 2023; 196:115594. [PMID: 37797539 DOI: 10.1016/j.marpolbul.2023.115594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 09/22/2023] [Accepted: 09/24/2023] [Indexed: 10/07/2023]
Abstract
There is growing awareness of the need to better constrain the contribution of atmospheric methane (CH4) fluxes from urbanized estuaries due to the high global warming potential of CH4 and the accelerating growth of urban expansion. This study undertook seasonal sampling campaigns to understand the impact of urbanization on atmospheric CH4 fluxes and their drivers in a large, tropical estuary in India. Overall, the study found that the Cochin estuary emitted large amounts of CH4 (398.8 ± 141.6 μmolm-2d-1) to the atmosphere with CH4 hotspots reaching up to 939.7 μmolm-2d-1 were identified. The strongest drivers of CH4 dynamics in different anthropogenically impacted zones were traced. The source of organic matter for CH4 production was revealed to be terrestrial C3 plants, autochthonous production, marine phytoplankton, and sewage inputs. The study suggests that monsoonal urbanized tropical estuaries may be an important but under-recognized element of the global CH4 budget.
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Affiliation(s)
- Regina Hershey N
- Dept. of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Cochin 682 016, India; Dept. of Zoology, Bharata Mata College, Thrikkakara, Cochin 682 021, India.
| | - Douglas R Tait
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales 2480, Australia.
| | - S Bijoy Nandan
- Dept. of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Cochin 682 016, India.
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11
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Caracciolo R, Escher BI, Lai FY, Nguyen TA, Le TMT, Schlichting R, Tröger R, Némery J, Wiberg K, Nguyen PD, Baduel C. Impact of a megacity on the water quality of a tropical estuary assessed by a combination of chemical analysis and in-vitro bioassays. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162525. [PMID: 36868276 DOI: 10.1016/j.scitotenv.2023.162525] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/30/2023] [Accepted: 02/24/2023] [Indexed: 05/06/2023]
Abstract
Tropical estuaries are threatened by rapid urbanization, which leads to the spread of thousands of micropollutants and poses an environmental risk to such sensitive aqueous ecosystems. In the present study, a combination of chemical and bioanalytical water characterization was applied to investigate the impact of Ho Chi Minh megacity (HCMC, 9.2 million inhabitants in 2021) on the Saigon River and its estuary and provide a comprehensive water quality assessment. Water samples were collected along a 140-km stretch integrating the river-estuary continuum from upstream HCMC down to the estuary mouth in the East Sea. Additional water samples were collected at the mouth of the four main canals of the city center. Chemical analysis was performed targeting up to 217 micropollutants (pharmaceuticals, plasticizers, PFASs, flame retardants, hormones, pesticides). Bioanalysis was performed using six in-vitro bioassays for hormone receptor-mediated effects, xenobiotic metabolism pathways and oxidative stress response, respectively, all accompanied by cytotoxicity measurement. A total of 120 micropollutants were detected and displayed high variability along the river continuum with total concentration ranging from 0.25 to 78 μg L-1. Among them, 59 micropollutants were ubiquitous (detection frequency ≥ 80 %). An attenuation was observed in concentration and effect profiles towards the estuary. The urban canals were identified as major sources of micropollutants and bioactivity to the river, and one canal (Bến Nghé) exceeded the effect-based trigger values derived for estrogenicity and xenobiotic metabolism. Iceberg modelling apportioned the contribution of the quantified and the unknown chemicals to the measured effects. Diuron, metolachlor, chlorpyrifos, daidzein, genistein, climbazole, mebendazole and telmisartan were identified as main risk drivers of the oxidative stress response and xenobiotic metabolism pathway activation. Our study reinforced the need for improved wastewater management and deeper evaluations of the occurrence and fate of micropollutants in urbanized tropical estuarine environments.
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Affiliation(s)
- Romane Caracciolo
- Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, Institute of Environmental Geosciences (IGE), 38000 Grenoble, France.
| | - Beate I Escher
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany; Eberhard Karls University Tübingen, Germany
| | - Foon Yin Lai
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), SE-75007 Uppsala, Sweden
| | - Truong An Nguyen
- Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, Institute of Environmental Geosciences (IGE), 38000 Grenoble, France; Asian Centre for Water Research (CARE)/HCMUT, Ho Chi Minh City, Viet Nam
| | - Thi Minh Tam Le
- Asian Centre for Water Research (CARE)/HCMUT, Ho Chi Minh City, Viet Nam; Ho Chi Minh University of Technology, Ho Chi Minh City, Viet Nam
| | - Rita Schlichting
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Rikard Tröger
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), SE-75007 Uppsala, Sweden
| | - Julien Némery
- Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, Institute of Environmental Geosciences (IGE), 38000 Grenoble, France; Asian Centre for Water Research (CARE)/HCMUT, Ho Chi Minh City, Viet Nam
| | - Karin Wiberg
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), SE-75007 Uppsala, Sweden
| | - Phuoc Dan Nguyen
- Asian Centre for Water Research (CARE)/HCMUT, Ho Chi Minh City, Viet Nam; Ho Chi Minh University of Technology, Ho Chi Minh City, Viet Nam
| | - Christine Baduel
- Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, Institute of Environmental Geosciences (IGE), 38000 Grenoble, France; Asian Centre for Water Research (CARE)/HCMUT, Ho Chi Minh City, Viet Nam.
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12
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Park JH, Lee H, Zhumabieke M, Kim SH, Shin KH, Khim BK. Basin-specific pollution and impoundment effects on greenhouse gas distributions in three rivers and estuaries. WATER RESEARCH 2023; 236:119982. [PMID: 37087919 DOI: 10.1016/j.watres.2023.119982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 05/03/2023]
Abstract
Large uncertainties exist regarding the combined effects of pollution and impoundment on riverine greenhouse gas (GHG) emissions. It has also been debated whether river eutrophication can transform downstream estuaries into carbon sinks. To assess human impacts on the riverine and estuarine distributions of CO2, CH4, and N2O, two source-to-estuary surveys along three impounded rivers in Korea were combined with multiple samplings at five or six estuarine sites. The basin-wide surveys revealed predominant pollution effects generating localized hotspots of riverine GHGs along metropolitan areas. The localized pollution effect was pronounced in the lower Han River and estuary adjacent to Seoul, while the highest GHG levels in the upper Yeongsan traversing Gwangju were not carried over into the faraway estuary. CH4 levels were elevated across the eutrophic middle Nakdong reaches regulated by eight cascade weirs in contrast to undersaturated CO2 indicating enhanced phytoplankton production. The levels of all three GHGs tended to be higher in the Han estuary across seasons. Higher summer-time δ13C-CH4 values at some Nakdong and Yeongsan estuarine sites implied that temperature-enhanced CH4 production may have been dampened by increased CH4 oxidation. Our results suggest that the location and magnitude of pollution sources and impoundments control basin-specific longitudinal GHG distributions and estuarine carryover effects, warning against simple generalizations of eutrophic rivers and estuaries as carbon sinks.
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Affiliation(s)
- Ji-Hyung Park
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
| | - Hyunji Lee
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Maidina Zhumabieke
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seung-Hee Kim
- Department of Marine Science and Convergence Engineering, Hanyang University ERICA, Ansan 15588, Republic of Korea
| | - Kyung-Hoon Shin
- Department of Marine Science and Convergence Engineering, Hanyang University ERICA, Ansan 15588, Republic of Korea
| | - Boo-Keun Khim
- Department of Oceanography and Marine Research Institute, Pusan National University, Busan 46241, Republic of Korea
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13
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Gubernat S, Masłoń A, Czarnota J, Koszelnik P, Chutkowski M, Tupaj M, Gumieniak J, Kramek A, Galek T. Removal of Phosphorus with the Use of Marl and Travertine and Their Thermally Modified Forms-Factors Affecting the Sorption Capacity of Materials and the Kinetics of the Sorption Process. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1225. [PMID: 36770230 PMCID: PMC9920275 DOI: 10.3390/ma16031225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/21/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
The paper presents new reactive materials, namely marl and travertine, and their thermal modifications and the Polonite® material, analyzing their phosphorus removal from water and wastewater by sorption. Based on the experimental data, an analysis of the factors influencing the sorption capacity of the materials, such as the material dose, pH of the initial solution, process temperature, surface structure, and morphology, was performed. Adsorption isotherms and maximum sorption capacities were determined with the use of the Langmuir, Freundlich, Langmuir-Freundlich, Tóth, Radke-Praunitz, and Marczewski-Jaroniec models. The kinetics of the phosphorus sorption process of the tested materials were described using reversible and irreversible pseudo-first order, pseudo-second order, and mixed models. The natural materials were the most sensitive to changes in the process conditions, such as temperature and pH. The thermal treatment process stabilizes the marl and travertine towards materials with a more homogeneous surface in terms of energy and structure. The fitted models of the adsorption isotherms and kinetic models allowed for an indication of a possible phosphorus-binding mechanism, as well as the maximum amount of this element that can be retained on the materials' surface under given conditions-raw marl (43.89 mg P/g), raw travertine (140.48 mg P/g), heated marl (80.44 mg P/g), heated travertine (282.34 mg P/g), and Polonite® (54.33 mg P/g).
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Affiliation(s)
- Sylwia Gubernat
- Doctoral School of Engineering and Technical Sciences at the Rzeszow University of Technology, Powstańców Warszawy 12, 35-959 Rzeszów, Poland
- Inżynieria Rzeszów S.A., ul. Podkarpacka 59A, 35-082 Rzeszów, Poland
| | - Adam Masłoń
- Department of Environmental and Chemistry Engineering, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland
| | - Joanna Czarnota
- Department of Environmental and Chemistry Engineering, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland
| | - Piotr Koszelnik
- Department of Environmental and Chemistry Engineering, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland
| | - Marcin Chutkowski
- Department of Chemical and Process Engineering, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland
| | - Mirosław Tupaj
- Department of Component Manufacturing and Production Organization, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, Poland
| | - Justyna Gumieniak
- Department of Component Manufacturing and Production Organization, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, Poland
| | - Agnieszka Kramek
- Department of Component Manufacturing and Production Organization, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, Poland
| | - Tomasz Galek
- Department of Integrated Design Systems and Tribology, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, Poland
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14
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Hong Z, Ma H, Zhang T, Wang Q, Chang Y, Song Y, Li Z, Cui F. Joint role of land cover types and microbial processing on molecular composition of dissolved organic matter in inland lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159522. [PMID: 36270364 DOI: 10.1016/j.scitotenv.2022.159522] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Anthropogenic activities have greatly changed the land use and land cover (LULC) and further influenced the chemical properties and amount of DOM transported into aquatic systems, meanwhile, microbial processing is also critical to DOM molecular composition in freshwaters. However, how they jointly shape DOM's chemical composition and chemodiversity in lakes is poorly understood. Here we examined DOM characteristics for seven inland lakes with three different land cover conditions (forest-dominated, cropland-dominated, and urban-dominated). Results indicated that DOM in cropland-dominated and forest-dominated lakes exhibited more characteristics of terrestrial organic matter, while urban-dominated lakes had more allochthonous organic matter driven by relatively high nutrient input. Human activities extended terrestrial DOM input to lakes and intensified the amount of heteroatomic organic molecules containing nitrogen and sulfur in lakes, with cropland contributing more N-containing compounds and urban contributing more S-containing compounds. Differential bacterial community composition appeared in the three types of land cover lakes, while strong co-occurrence/exclusion patterns between specific microbes and molecular formula groups revealed the key DOM metabolism functions of these bacteria. Matrix correlations based on Mantel tests confirmed that watershed landcover status was a dominating factor for DOM sources and molecular composition in mountainous lakes through direct input of terrestrial organic matter, and microbial processing was not the key factor for DOM molecular formula. Our findings help to assess the influence of human activities and microbial processing in the transfer and transformation of DOM in environmental waters.
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Affiliation(s)
- Zhicheng Hong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Hua Ma
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China; College of Environment and Ecology, Chongqing University, Chongqing, China.
| | - Ting Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Qianru Wang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Yilin Chang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Yingyue Song
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Zhe Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China
| | - Fuyi Cui
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing, China; College of Environment and Ecology, Chongqing University, Chongqing, China
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15
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Wang X, Yu L, Liu T, He Y, Wu S, Chen H, Yuan X, Wang J, Li X, Li H, Que Z, Qing Z, Zhou T. Methane and nitrous oxide concentrations and fluxes from heavily polluted urban streams: Comprehensive influence of pollution and restoration. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 313:120098. [PMID: 36075337 DOI: 10.1016/j.envpol.2022.120098] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Streams draining urban areas are usually regarded as hotspots of methane (CH4) and nitrous oxide (N2O) emissions. However, little is known about the coupling effects of watershed pollution and restoration on CH4 and N2O emission dynamics in heavily polluted urban streams. This study investigated the CH4 and N2O concentrations and fluxes in six streams that used to be heavily polluted but have undergone different watershed restorations in Southwest China, to explore the comprehensive influences of pollution and restoration. CH4 and N2O concentrations in the six urban streams ranged from 0.12 to 21.32 μmol L-1 and from 0.03 to 2.27 μmol L-1, respectively. The calculated diffusive fluxes of CH4 and N2O were averaged of 7.65 ± 9.20 mmol m-2 d-1 and 0.73 ± 0.83 mmol m-2 d-1, much higher than those in most previous reports. The heavily polluted streams with non-restoration had 7.2 and 7.8 times CH4 and N2O concentrations higher than those in the fully restored streams, respectively. Particularly, CH4 and N2O fluxes in the fully restored streams were 90% less likely than those found in the unrestored ones. This result highlighted that heavily polluted urban streams with high pollution loadings were indeed hotspots of CH4 and N2O emissions throughout the year, while comprehensive restoration can effectively weaken their emission intensity. Sewage interception and nutrient removal, especially N loadings reduction, were effective measures for regulating the dynamics of CH4 and N2O emissions from the heavily polluted streams. Based on global and regional integration, it further elucidated that increasing environment investments could significantly improve water quality and mitigate CH4 and N2O emissions in polluted urban streams. Overall, our study emphasized that although urbanization could inevitably strengthen riverine CH4 and N2O emissions, effective eco-restoration can mitigate the crisis of riverine greenhouse gas emissions.
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Affiliation(s)
- Xiaofeng Wang
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China.
| | - Lele Yu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Tingting Liu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241, China
| | - Yixin He
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China
| | - Shengnan Wu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Huai Chen
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China
| | - Xingzhong Yuan
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China
| | - Jilong Wang
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Xianxiang Li
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Hang Li
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Ziyi Que
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Zhaoyin Qing
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Ting Zhou
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
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