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Li Y, Liu Y, Yu S, Xing B, Xu X, Yu H, Wang L, Wang D, Liu C, Yu D. Vigilance against climate change-induced regime shifts for phosphorus restoration in shallow lake ecosystems. WATER RESEARCH 2025; 278:123397. [PMID: 40043580 DOI: 10.1016/j.watres.2025.123397] [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: 10/30/2024] [Revised: 01/25/2025] [Accepted: 02/25/2025] [Indexed: 04/14/2025]
Abstract
The dual pressure of anthropogenic activities and frequent extreme weather events has triggered a transition from macrophyte to algal dominance in shallow lakes. Phosphorus (P) is the key driver of regime shifts that can lead to a decline in the stability and resilience of lake ecosystems. However, the mechanisms underlying such regime shifts, and the effects of state transitions on internal P loading during macrophyte restoration in large shallow eutrophic lakes, remain to be fully elucidated. This study utilised long-term in situ monitoring data, across three distinct lake states (bare ground, macrophyte-dominated stage, and algae-dominated stage) to elucidate the accumulation and release mechanisms of sedimentary P during regime shifts. The findings demonstrated that the rehabilitation of submerged plants efficiently reduced internal P loading (water column P, sediment P fractions, and P flux), while the persistence of algal blooms was driven by the reductive release of Fe-P from sediments and the dissolution of Al-P from suspended particulate matter. High temperature, low dissolved oxygen, and high pH largely modulate the pathways and mechanisms of P supply during regime shifts. The combined pressures of extreme weather (heavy rainfall, strong winds, and extreme heat) and trophic cascades from fish stocking can trigger a shift from macrophytes to algae in shallow lakes. Appropriate management of the structure and biomass of aquatic animal communities (e.g., small-bodied or omnibenthivorous fish) and optimization of the food web structure can effectively improve water quality and maintain ecosystem stability. These findings enrich the theoretical understanding of regime-shift mechanisms from an ecosystem perspective and offer novel insights into P remediation in large shallow eutrophic lakes.
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Affiliation(s)
- Yang Li
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China; School of Resource and Environmental Sciences, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Wuhan University, Wuhan 430072, PR China
| | - Yuan Liu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Siqi Yu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Bin Xing
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Xinwei Xu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Haihao Yu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Ligong Wang
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China
| | - Dihua Wang
- School of Resource and Environmental Sciences, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Wuhan University, Wuhan 430072, PR China
| | - Chunhua Liu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China.
| | - Dan Yu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan 430072, PR China.
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He X, Yan W, Chen X, Wang Y, Li M, Li Q, Jin J, Yu Z, Wu T. The transition from macrophyte-dominated to algae-dominated lake systems enhances arsenic release from sediments. WATER RESEARCH 2025; 276:123233. [PMID: 39908591 DOI: 10.1016/j.watres.2025.123233] [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: 10/27/2024] [Revised: 01/28/2025] [Accepted: 01/30/2025] [Indexed: 02/07/2025]
Abstract
Declining macrophytes in eutrophic lakes are altering material cycling in sediments. However, the transformation of arsenic (As) in response to these changes remains poorly understood. In this study, high-resolution dialysis was used to measure dissolved As in sediments from macrophyte-dominated (MD) and algae-dominated (AD) zones across different seasons. The relationship between sedimentary As fractionation and environmental variations was analyzed, and the As transformation process was explored. Results showed that the shift from macrophyte- to algae-dominated zones enhanced As release in sediments. Dissolved As in pore water of AD peaked at 120.36 μg/L in summer, exhibiting the highest release intensity, while MD showed a notable As release profile in spring (34.92 μg/L). In spring, decomposition and acidification of macrophyte residues, along with organic matter (OM) complexation, promoted the release of adsorbed As in MD. In contrast, reduction and dissolution of iron (Fe) oxides, along with competition for adsorption sites by dissolved phosphorus (P), drove As release in AD during summer. The high humification and low redox potential in MD sediments in summer promoted As-S co-precipitation, leading to As sequestration instead of release, this contrasts with the common view that warmer temperatures favor As release from sediments. The conversion from macrophytes to algae in eutrophic lakes may exacerbate the risk of As release, warranting further investigation.
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Affiliation(s)
- Xiangyu He
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Wenming Yan
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
| | - Xiang Chen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Yan Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Minjuan Li
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Qi Li
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Junliang Jin
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; Yangtze Institute for conservation and development, Hohai University, Nanjing 210098, China
| | - Zhongbo Yu
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; Yangtze Institute for conservation and development, Hohai University, Nanjing 210098, China
| | - Tingfeng Wu
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China; Yangtze Institute for conservation and development, Hohai University, Nanjing 210098, China
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3
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Guo M, Yu M, Wang X, Xiao N, Huguet A, Zhang Y, Liu G. Deciphering the link between particulate organic matter molecular composition and lake eutrophication by FT-ICR MS analysis. WATER RESEARCH 2025; 272:122936. [PMID: 39674138 DOI: 10.1016/j.watres.2024.122936] [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: 12/12/2023] [Revised: 09/25/2024] [Accepted: 12/07/2024] [Indexed: 12/16/2024]
Abstract
Eutrophication has emerged as a significant environmental problem for global lakes. As an essential carrier of nutrients, particulate organic matter (POM) plays a vital role in the eutrophication process of these aquatic systems. In this study, POM from seven lakes with different trophic states in the middle and lower reaches of the Yangtze River (China) was characterized using carbon and nitrogen stable isotopes and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The aim was to elucidate the relationship between the source and molecular composition of POM during the eutrophication process of lakes. The results indicated that POM was mainly composed of autochthonous (62.7%) and allochthonous (37.3%) sources, with the contribution from autochthonous sources being more pronounced across the different sources. The POM formulas mainly consisted of the subclasses CHO, CHON, CHOP, CHOS, and CHONS. Notably, CHOP formulas had the highest proportion of labile formula compounds, according for 51.56%. The unsaturation, aromaticity, and oxidation of unique POM formulas gradually decreased with increasing trophic states. A significant positive correlation was observed between CHOP and the percentage of labile compounds (MLBL%) in unique POM formulas. The relative abundance of lipid and protein compounds of unique POM formulas showed a positive correlation with lake trophic states, which indicated that with the increase of lake trophic states, the content of autochthonous POM gradually increased. Herein, we inferred that with the intensification of lake eutrophication, the autochthonous POM increased, which was accompanied by a further increase of labile P-containing compounds in POM, thus leading to the increasing eutrophication process of lakes in the form of positive feedback. Overall, this investigation of POM at the molecular level illustrates the deep-rooted mechanism of frequent lake eutrophication. This is of great significance in understanding the fate of POM and effectively controlling lake eutrophication.
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Affiliation(s)
- Minli Guo
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Mingxing Yu
- Changjiang Basin Ecology and Environment Monitoring and Scientific Research Center, Changjiang Basin Ecology and Environment Administration, Ministry of Ecology and Environment, Wuhan 430010, China
| | - Xu Wang
- River Basin Complex Administration, China Three Gorges Corporation, Yichang, 443133, China
| | - Naidong Xiao
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Arnaud Huguet
- Sorbonne Université, CNRS, EPHE, PSL, UMR METIS, F-75005 Paris, France
| | - Yunlin Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Guanglong Liu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China.
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Wu X, Wang Y, Jiao L, He J, Zhou H, Hao Z. Influencing Factors of Phosphorus Mobility and Retention in the Sediment of Three Typical Plateau Lakes. TOXICS 2025; 13:120. [PMID: 39997935 PMCID: PMC11860908 DOI: 10.3390/toxics13020120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2024] [Revised: 01/30/2025] [Accepted: 01/31/2025] [Indexed: 02/26/2025]
Abstract
The mechanisms driving changes in the stability of phosphorus (P) in sediments under lake ecosystem degradation remain poorly understood. This study investigated the P-binding forms in sediments from three plateau lakes with different trophic states in Yunnan Province, China, aiming to elucidate the responses of sediment P compositions to human activities, lake trophic status, and dissolved organic matter (DOM) characteristics. The results showed that human activity directly contributed to sediment P retention. The trophic type of lake exerted a discernible effect on P mobility in the sediments, as eutrophic algae-type lakes had a higher content of sediment mobile-P. Moreover, the sediment DOM promoted the adsorption of BD-P and NH4Cl-P. Generally, exogenous pollution caused by human activity leads to lake eutrophication and a decline in lake ecosystem stability. This variation was largely influenced by water depth. A decrease in lake ecosystem stability leads to increased P mobility in sediments, which increases the risk of endogenous pollution. The DOM plays an important role in the mobility of sediment P. These insights offer a novel perspective for understanding how lake ecosystem characteristics are related to endogenous P loads in lakes.
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Affiliation(s)
- Xue Wu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China;
- Kunming Institute of Eco-Environmental Sciences, Kunming 650032, China; (Y.W.); (H.Z.)
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yancai Wang
- Kunming Institute of Eco-Environmental Sciences, Kunming 650032, China; (Y.W.); (H.Z.)
| | - Lixin Jiao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jia He
- Kunming Institute of Eco-Environmental Sciences, Kunming 650032, China; (Y.W.); (H.Z.)
| | - Hongbin Zhou
- Kunming Institute of Eco-Environmental Sciences, Kunming 650032, China; (Y.W.); (H.Z.)
| | - Zhengzheng Hao
- Yunnan Dianwei Environmental Protection Technology Co., Ltd., Kunming 650031, China;
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Guo Y, Sun F, Wang J, Wang Z, Yang H, Wu F. Application of Synchronous Evaluation-Diagnosis Model with Quantitative Stressor-Response Analysis (SED-QSR) to Urban Lake Ecological Status: A Proposed Multiple-Level System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:16028-16039. [PMID: 39207301 DOI: 10.1021/acs.est.4c04901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Ecological integrity assessment and degradation diagnosis are used globally to evaluate the health of water bodies and pinpoint critical stressors. However, current studies mainly focus on separate evaluation or diagnosis, leading to an inadequate exploration of the relationship between stressors and responses. Here, based on multiple data sets in an urban lake system, a synchronous evaluation-diagnosis model with quantitative stressor-response analysis was advanced, aiming to improve the accuracy of evaluation and diagnosis. The weights for key physicochemical stressors were quantitatively determined in the sequence of NDAVIadj > CODMn > TP > NH4+-N by the combination of generalized additive model and structural equation modeling, clarifying the most significant effects of aquatic vegetation on the degradation of fish assemblages. Then, sensitive biological metrics were screened by considering the distinct contributions of four key stressors to alleviate the possible deviation caused by common methods. Finally, ecological integrity was evaluated by summing the key physicochemical stressors and sensitive biological metrics according to the model-deduced weights instead of empirical weights. Our system's diagnosis and evaluation results achieved an accuracy of over 80% when predicting anthropogenic stress and biological status, which highlights the great potential of our multiple-level system for ecosystem management.
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Affiliation(s)
- Yiding Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Fuhong Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Jie Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Ziteng Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Hao Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
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Guo Y, Liu X, Dong Y, Ni Z, Zhou C, Chen C, Wang S, Chen Q, Yan Y. The continuous increased stability of sediment dissolved organic matter implies ecosystem degradation of lakes in the cold and arid regions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174384. [PMID: 38964389 DOI: 10.1016/j.scitotenv.2024.174384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/06/2024]
Abstract
The characteristics of lake dissolved organic matter (DOM) pool and lake ecosystem interact, and studying the responses between sediment DOM characteristics and lake ecosystem changes may shed light on the inherent connection between ecosystem evolution and carbon biogeochemical cycles. Lakes in cold and arid regions are sensitive to changes and accumulate large amounts of carbon as DOM, which may provide a window into more explicit relationships between ecosystem evolution and changes in sediment DOM characteristics in time dimension. However, considerable blind spots exist in the responses between the sediment DOM and ecosystem evolution on time scale and the underlying mechanisms. In this study, multiple approaches were combined to investigate the relationship between the variation trend of sediment DOM characteristics and the evolution of fragile lake ecosystems across three different lake ecosystems in cold and arid regions of China. A strong positive relationship between sediment DOM stabilities, especially humification, and ecosystem degradation was found, consistent for the three lakes. Ultra-high-resolution mass spectrometry and structural equation modeling revealed that the changes of ecosystems affected sediment DOM stability through direct pathways (0.24), such as the contents of terrestrial DOM in lake DOM pool, and indirect pathways, including algae-mediated (0.43) and salinity-mediated pathways (0.22), which all increased the contents of refractory DOM in the lake DOM pool and sediments. Based on the fact that DOM stability changes could act on the ecosystem in turn, a possible positive feedback mechanism between ecosystem degradation and increased DOM stability was further inferred. These results suggested that the continuous increased stability of sediment DOM in may implies ecosystem degradation of lakes in the cold and arid regions. This study provides a new perspective for recognizing ecosystem evolution through sediment DOM and improves the understanding of the interaction of lake ecosystem evolution and the biogeochemical cycle of DOM.
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Affiliation(s)
- Ying Guo
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - XiaoFei Liu
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Yue Dong
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Zhaokui Ni
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Chunyang Zhou
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Chao Chen
- Instrumentation and Service Center for Science and Technology, Beijing Normal University at Zhuhai, Zhuhai 519087, China
| | - Shengrui Wang
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed, Kunming, Yunnan Province 650034, China.
| | - Qiuying Chen
- North China Institute of Science and Technology, School of Chemical Safety, Langfang 101601, China
| | - Yanting Yan
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
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Cheng Y, Ding S, Shao Z, Song D, Jiao L, Zhang W, Duan P, He J. Persistence of dissolved organic matter in sediments influenced by environmental factors:Implication for nutrition and carbon cycle. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 363:121387. [PMID: 38850914 DOI: 10.1016/j.jenvman.2024.121387] [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: 10/13/2023] [Revised: 04/20/2024] [Accepted: 06/03/2024] [Indexed: 06/10/2024]
Abstract
The persistence of dissolved organic matter (DOM) plays a crucial role in the cycling and distribution of carbon and nutrients. Nonetheless, our understanding of how environmental alterations affect the persistence of sedimentary DOM remains incomplete. Excitation Emission Fluorescence Matrix-Parallel Factor Analysis (EEM-PARAFAC) was used to examine the fluorescence and compositional characteristics of hydrophilic and hydrophobic DOM (separated using XAD-8 resin) within sediments from twelve lakes and reservoirs. Fluorescence analysis indicated that DOM persistence is dependent on the proportions of the three components derived from PARAFAC. The Mantel test showed that climatic factors had the most significant impact on DOM persistence (Mantel's r = 0.46-0.54, Mantel's p = 0.001-0.007), while anthropogenic (Mantel's r = 0.24-0.32, Mantel's p = 0.03-0.05) and hydrological factors (Mantel's r = 0.03-0.22, Mantel's p = 0.06-0.40) had a somewhat lesser influence. Environmental changes resulted in a consistent decline in DOM persistence from Northeast to Southwest China, accompanied by an increase in gross primary productivity (GPP). Reduced DOM persistence due to climate, hydrological, and anthropogenic factors may lead to elevated concentrations of total phosphorus (TP), contributing to deteriorating water quality and events such as algal blooms. The decline in water quality due to reduced DOM persistence in lakes with high GPP can exacerbate the transition from carbon sinks to carbon sources. Consequently, the persistence of sedimentary DOM significantly influences nutrient and carbon cycling in lakes. Investigating DOM persistence in lakes across diverse geographic locations offers a new perspective on lake eutrophication and carbon emissions. Furthermore, it is crucial to develop targeted recommendations for lake restoration and management.
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Affiliation(s)
- Yunxuan Cheng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Institute of Water Environment Research, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Yunnan Key Laboratory for Pollution Processes and Control of Plateau Lake-Watersheds, Kunming, 650032, China
| | - Shuai Ding
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Institute of Water Environment Research, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhi Shao
- Kunming Institute of Eco-Environmental Sciences, Kunming, 650032, China
| | - Di Song
- Yunnan Key Laboratory for Pollution Processes and Control of Plateau Lake-Watersheds, Kunming, 650032, China; Yunnan Academy of Ecological and Environmental Sciences, Kunming, 650032, China
| | - Lixin Jiao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Institute of Water Environment Research, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Yunnan Key Laboratory for Pollution Processes and Control of Plateau Lake-Watersheds, Kunming, 650032, China.
| | - Weizhen Zhang
- School of Ecological Environment, Chengdu University of Technology, Chengdu, 610059, China
| | - Pingzhou Duan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Institute of Water Environment Research, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jia He
- Kunming Institute of Eco-Environmental Sciences, Kunming, 650032, China.
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Tao Y, Ren J, Zhu H, Li J, Cui H. Exploring Spatiotemporal Patterns of Algal Cell Density in Lake Dianchi with Explainable Machine Learning. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 356:124395. [PMID: 38901816 DOI: 10.1016/j.envpol.2024.124395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/29/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
The escalating global occurrence of algal blooms poses a growing threat to ecosystem services. In this study, the spatiotemporal heterogeneity of water quality parameters was leveraged to partition Lake Dianchi into three clusters. Considering water quality parameters and both the delayed and instantaneous effects of meteorological factors, ensemble learning, and quasi-Monte Carlo methods were employed to predict daily algal cell density (AD) between January 2021 and January 2024. Consistently, superior predictive accuracy across all three clusters was exhibited by the Stacking-Elastic-Net regularization model. Furthermore, the minimum combination of drivers that achieved near-optimal accuracy for each cluster was identified, striking a balance between accuracy and cost. The ranking of the effect of drivers on AD varied by cluster, while the delayed effect of meteorological factors on AD generally outweighed their instantaneous effect for all clusters. Additionally, the heterogeneous or homogeneous thresholds and responses between drivers and AD were explored. These findings could serve as a scientific and cost-effective basis for government agencies to develop regional sustainable strategies for managing water quality.
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Affiliation(s)
- Yiwen Tao
- School of Mathematics and Statistics, Zhengzhou University, Zhengzhou, 450001, Henan, China; Archaeology Innovation Center, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Jingli Ren
- School of Mathematics and Statistics, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Huaiping Zhu
- LAMPS, Department of Mathematics and Statistics, York university, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Jian Li
- Archaeology Innovation Center, Zhengzhou University, Zhengzhou, 450001, Henan, China; School of Geoscience and Technology, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Hao Cui
- Archaeology Innovation Center, Zhengzhou University, Zhengzhou, 450001, Henan, China; School of Geoscience and Technology, Zhengzhou University, Zhengzhou, 450001, Henan, China.
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Kang L, Zhu M, Zhu G, Xu H, Zou W, Xiao M, Guo C, Zhang Y, Qin B. Decreasing denitrification rates poses a challenge to further decline of nitrogen concentration in Lake Taihu, China. WATER RESEARCH 2024; 256:121565. [PMID: 38581985 DOI: 10.1016/j.watres.2024.121565] [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: 01/02/2024] [Revised: 02/29/2024] [Accepted: 04/01/2024] [Indexed: 04/08/2024]
Abstract
Nitrogen (N) concentrations in many lakes have decreased substantially in recent years due to external load reduction to mitigate harmful algal blooms. However, little attention has been paid to the linkage between the lakes' nitrogen removal efficiency and improved water quality in lakes, especially the variation of denitrification rate (DNR) under decreasing N concentrations. To understand the efficiency of N removal under improving water quality and its influence on the N control targets in Lake Taihu, a denitrification model based on in situ experimental results was developed and long-term (from 2007 to 2022) water quality and meteorological observations were used to estimate DNR and relate it to the amount of N removal (ANR) from the lake. The concentration of total nitrogen (TN) in Lake Taihu decreased from 3.28 mg L-1 to 1.41 mg L-1 from 2007 to 2022 but the reduction showed spatial heterogeneity. The annual mean DNR decreased from 45.6 μmol m-2 h-1 to 4.2 μmol m-2 h-1, and ANR decreased from 11.85×103 t yr-1 to 1.17×103 t yr-1 during the study years. N budget analysis suggested that the amount of N removed by denitrification accounted for 23.3 % of the external load in 2007, but decreased to only 4.0 % in 2022. Thus, the contribution of N removal by internal N cycling decreased significantly as water quality improved. Notably, the proportion of ANR in winter to total ANR increased from 14 % in 2007 to 23 % in 2022 due to warming. This could potentially lead to N deficiencies in spring and summer, thus limiting the availability of N to phytoplankton. A TN concentration of less than 1.0 mg L-1 in the lake and 1.5 mg L-1 in the inflowing lake zones in spring contribute to local N-limitation in Lake Taihu for cyanobacteria control. Our study revealed a general pattern that N removal efficiency decreases with improved water quality, which is instructive for eutrophic lakes in nitrogen management.
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Affiliation(s)
- Lijuan Kang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Mengyuan Zhu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Guangwei Zhu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Hai Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Wei Zou
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Man Xiao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Chaoxuan Guo
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Yunlin Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Boqiang Qin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
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Liu C, Shen Q, Gu X, Zhang L, Han C, Wang Z. Burial or mineralization: Origins and fates of organic matter in the water-suspended particulate matter-sediment of macrophyte- and algae-dominated areas in Lake Taihu. WATER RESEARCH 2023; 243:120414. [PMID: 37516078 DOI: 10.1016/j.watres.2023.120414] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/06/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Abstract
Increased algal blooms and loss of aquatic vegetation are critical environmental issues associated with shallow lakes worldwide. The increase in organic matter (OM) in both macrophyte-dominated areas (MDAs) and algae-dominated areas (ADAs) has exacerbated these problems. Most OM in water is concentrated as suspended particulate matter (SPM), which eventually migrates to the sediment. However, the detailed origins and fates of OM in water-SPM-sediment systems with coexisting MDAs and ADAs remain unclear. Therefore, in this study, we conducted monthly field investigations in Lake Taihu, focusing on OM-migration patterns in an MDA and an ADA. The C/N mass ratios, δ13C contents, and OM compositions of the water, SPM, and sediment were analyzed. Our findings revealed that autochthonous sources of OM prevailed in water, whereas terrestrial sources prevailed in SPM and sediment. Rapid decomposition processes of microbial- and algae-derived dissolved OM were discovered along the water-SPM-sediment pathways in both areas. A trend towards a shift from macrophytes to algae in the MDA was also discovered. Overall, the entire lake underwent a burial process of OM in both types of areas, with mineralization mostly occurring during the algal-bloom seasons and more strongly in the ADA. Furthermore, we deduced that a decrease in the OM-burial rate, but an increase in the mineralization rate, might occur after a complete shift from a macrophyte- to an algae-dominated status. Such a shift might change the carbon-cycle process in eutrophic shallow lakes and should be given more attention in future research.
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Affiliation(s)
- Cheng Liu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Qiushi Shen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xiaozhi Gu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Lei Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Chao Han
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Zhaode Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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