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Cai G, Ge Y, Dong Z, Liao Y, Chen Y, Wu A, Li Y, Liu H, Yuan G, Deng J, Fu H, Jeppesen E. Temporal shifts in the phytoplankton network in a large eutrophic shallow freshwater lake subjected to major environmental changes due to human interventions. WATER RESEARCH 2024; 261:122054. [PMID: 38986279 DOI: 10.1016/j.watres.2024.122054] [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: 04/26/2024] [Revised: 07/02/2024] [Accepted: 07/04/2024] [Indexed: 07/12/2024]
Abstract
Phytoplankton communities are crucial components of aquatic ecosystems, and since they are highly interactive, they always form complex networks. Yet, our understanding of how interactive phytoplankton networks vary through time under changing environmental conditions is limited. Using a 29-year (339 months) long-term dataset on Lake Taihu, China, we constructed a temporal network comprising monthly sub-networks using "extended Local Similarity Analysis" and assessed how eutrophication, climate change, and restoration efforts influenced the temporal dynamics of network complexity and stability. The network architecture of phytoplankton showed strong dynamic changes with varying environments. Our results revealed cascading effects of eutrophication and climate change on phytoplankton network stability via changes in network complexity. The network stability of phytoplankton increased with average degree, modularity, and nestedness and decreased with connectance. Eutrophication (increasing nitrogen) stabilized the phytoplankton network, mainly by increasing its average degree, while climate change, i.e., warming and decreasing wind speed enhanced its stability by increasing the cohesion of phytoplankton communities directly and by decreasing the connectance of network indirectly. A remarkable shift and a major decrease in the temporal dynamics of phytoplankton network complexity (average degree, nestedness) and stability (robustness, persistence) were detected after 2007 when numerous eutrophication mitigation efforts (not all successful) were implemented, leading to simplified phytoplankton networks and reduced stability. Our findings provide new insights into the organization of phytoplankton networks under eutrophication (or re-oligotrophication) and climate change in subtropical shallow lakes.
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Affiliation(s)
- Guojun Cai
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China; Institute of Mountain Resources, Guizhou Academy of Science, Guiyang 550001, China
| | - Yili Ge
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Zheng Dong
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Yu Liao
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Yaoqi Chen
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Aiping Wu
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Youzhi Li
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Huanyao Liu
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Guixiang Yuan
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China
| | - Jianming Deng
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Hui Fu
- Ecology Department, College of Environments & Ecology, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, China.
| | - Erik Jeppesen
- Department of Ecoscience and Centre for Water Technology (WATEC), Aarhus University, Vejlsøvej 25, Silkeborg 8600, Denmark; Sino-Danish Centre for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, China; imnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey; Institute of Marine Sciences, Middle East Technical University, Erdemli-Mersin 33731, Turkey; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China
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2
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Catalan J, Monteoliva AP, Vega JC, Domínguez A, Negro AI, Alonso R, Garcés BV, Batalla M, García-Gómez H, Leira M, Nuño C, Pahissa J, Peg M, Pla-Rabés S, Roblas N, Vargas JL, Toro M. Reduced precipitation can induce ecosystem regime shifts in lakes by increasing internal nutrient recycling. Sci Rep 2024; 14:12408. [PMID: 38811751 PMCID: PMC11137141 DOI: 10.1038/s41598-024-62810-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/21/2024] [Indexed: 05/31/2024] Open
Abstract
Eutrophication is a main threat to continental aquatic ecosystems. Prevention and amelioration actions have been taken under the assumption of a stable climate, which needs reconsideration. Here, we show that reduced precipitation can bring a lake ecosystem to a more productive regime even with a decline in nutrient external load. By analyzing time series of several decades in the largest lake of the Iberian Peninsula, we found autocorrelated changes in the variance of state variables (i.e., chlorophyll and oxygen) indicative of a transient situation towards a new ecosystem regime. Indeed, exceptional planktonic diatom blooms have occurred during the last few years, and the sediment record shows a shift in phytoplankton composition and an increase in nutrient retention. Reduced precipitation almost doubled the water residence time in the lake, enhancing the relevance of internal processes. This study demonstrates that ecological quality targets for aquatic ecosystems must be tailored to the changing climatic conditions for appropriate stewardship.
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Grants
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
- 452-A-640.01.01/2014 Confederación Hidrográfica del Duero (Ministry for the Ecological Transition and the Demographic Challenge, Spain)
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Affiliation(s)
- Jordi Catalan
- CSIC, Bellaterra, Barcelona, Spain.
- CREAF, Cerdanyola del Vallés, Barcelona, Spain.
| | | | - José Carlos Vega
- Laboratorio de Limnología, Parque Natural del Lago de Sanabria y Alrededores, Rabanillo-Galende, Zamora, Spain
| | | | - Ana I Negro
- Area of Ecology, Faculty of Biology, University of Salamanca, Salamanca, Spain
| | - Rocío Alonso
- Ecotoxicology of Air Pollution, Environment Department, CIEMAT, Madrid, Spain
| | | | | | - Héctor García-Gómez
- Ecotoxicology of Air Pollution, Environment Department, CIEMAT, Madrid, Spain
| | - Manel Leira
- Department of Functional Biology, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Carlos Nuño
- Centre for Hydrographic Studies, CEDEX, Madrid, Spain
| | | | - María Peg
- Centre for Hydrographic Studies, CEDEX, Madrid, Spain
| | - Sergi Pla-Rabés
- CREAF, Cerdanyola del Vallés, Barcelona, Spain
- Unitat Ecologia, BABVE, Universitat Autònoma de Barcelona, Cerdanyola del Vallés, Barcelona, Spain
| | | | | | - Manuel Toro
- Centre for Hydrographic Studies, CEDEX, Madrid, Spain
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3
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Wu Y, Peng C, Li G, He F, Huang L, Sun X, Wu S. Integrated evaluation of the impact of water diversion on water quality index and phytoplankton assemblages of eutrophic lake: A case study of Yilong Lake. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 357:120707. [PMID: 38554455 DOI: 10.1016/j.jenvman.2024.120707] [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: 12/22/2023] [Revised: 03/11/2024] [Accepted: 03/18/2024] [Indexed: 04/01/2024]
Abstract
Water diversion has been widely utilized to enhance lake water quality and mitigate cyanobacterial blooms. However, previous studies have mainly focused on investigating the effects of water diversion on water quality or aquatic ecological health. Consequently, there is limited research investigating the combined impact of water diversion on the water quality and the ecological health of eutrophic lakes, and whether the WQI and phytoplankton assemblages demonstrate similar patterns following water diversion. In this study, the effects of water diversion on the ecosystem health of eutrophic lakes were comprehensively evaluated based on the WQI indices and phytoplankton assemblages during the NWDP-21 and WDP-22. The results showed that the annual mean of WQI increased from 52.02 to 54.36 after water diversion, which improved the water quality of the lake, especially NH3-N and TN decreased by 58.6% and 15.2%, respectively. The phytoplankton assemblages changed significantly before and after water diversion, and we observed that the total biomass of phytoplankton decreased by 12.3% and phytoplankton diversity indices (Shannon-Wiener diversity, Pielou evenness, and Simpson index) increased by 8.6%-8.9% after water diversion, with an improvement in the connectivity and stability of the phytoplankton. Notably, enhanced adaptations of rare sub-communities for resource use in water diversion environments, and water diversion inhibited the dispersal ability of dominant functional groups, and the effects of hydrological disturbances on the structure of phytoplankton assemblage favored the ecological health of eutrophic lakes. VPA analysis further reveals that water diversion alters the drivers of phytoplankton functional group biomass and phytoplankton diversity. The results of the PLS-PM analysis clarify that water diversion indirectly impacts the total phytoplankton biomass and phytoplankton diversity primarily by modifying light availability. Significant correlations are observed between the dominant functional groups biomass and diversity indices of WQI. The trends in changes observed in water quality indices and phytoplankton following water diversion align with the evaluation of water ecological health. This study provides valuable guidance for the ecological management of the diversion project in Yilong Lake and serves as a reference for similar projects in other lakes.
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Affiliation(s)
- Yundong Wu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengrong Peng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; Yangtze Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
| | - Genbao Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming 650228, PR China.
| | - Feng He
- Kunming Dianchi and Plateau Lakes Institute, Kunming 650228, PR China; Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming 650228, PR China
| | - Licheng Huang
- Kunming Dianchi and Plateau Lakes Institute, Kunming 650228, PR China; Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming 650228, PR China
| | - Xiuqiong Sun
- Bureau of Yilong Lake Administration, Shiping 662200, PR China
| | - Sirui Wu
- Bureau of Yilong Lake Administration, Shiping 662200, PR China
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4
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Fu H, Ge Y, Cai G, Deng J, Liu H, Wu A, Li Y, Li W, Yuan G, Jeppesen E. Weakened casual feedback loops following intensive restoration efforts and climate changes in a large shallow freshwater lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169601. [PMID: 38159751 DOI: 10.1016/j.scitotenv.2023.169601] [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: 08/21/2023] [Revised: 11/15/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
Understanding how phytoplankton interacts with local and regional drivers as well as their feedbacks is a great challenge, and quantitative analyses of the regulating role of human activities and climate changes on these feedback loops are also limited. By using monthly monitoring dataset (2000-2017) from Lake Taihu and empirical dynamic modelling to construct causal networks, we quantified the strengths of causal feedbacks among phytoplankton, local environments, zooplankton, meteorology as well as global climate oscillation. Prevalent bidirectional causal linkages between phytoplankton biomass (chlorophyll a) and the tested drivers were found, providing holistic and quantitative evidence of the ubiquitous feedback loops. Phytoplankton biomass exhibited the highest feedbacks with total inorganic nitrogen and ammonia and the lowest with nitrate. The feedbacks between phytoplankton biomass and environmental factors from 2000 to 2017 could be classified into two groups: the local environments (e.g., nutrients, pH, transparency, zooplankton biomass)-driven enhancement loops promoting the response of the phytoplankton biomass, and the climate (e.g., wind speed)-driven regulatory loops suppressing it. The two counterbalanced groups modified the emergent macroecological patterns. Our findings revealed that the causal feedback networks loosened significantly after 2007 following nutrient loading reduction and unsuccessful biomanipulation restoration attempts by stocking carp. The strength of enhancement loops underwent marked decreases leading to reduced phytoplankton responses to the tested drivers, while the climate (decreasing wind speed, warming winter)-driven regulatory loops increased- like a tug-of-war. To counteract the self-amplifying feedback loops, the present eutrophication mitigation efforts, especially nutrient reduction, should be continued, and introduction of alternative measures to indirectly regulate the critical components (e.g., pH, Secchi depth, zooplankton biomass) of the loops would be beneficial.
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Affiliation(s)
- Hui Fu
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China.
| | - Yili Ge
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Guojun Cai
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Jianmin Deng
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China.
| | - Huanyao Liu
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Aiping Wu
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Youzhi Li
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Wei Li
- Research Institute of Ecology & Environmental Sciences, Nanchang Institute of Technology, Nanchang 330099, PR China
| | - Guixiang Yuan
- Ecology Department, College of Resources & Environments, Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Hunan Agricultural University, Changsha 410128, PR China
| | - Erik Jeppesen
- Department of Bioscience and Centre for Water Technology/WATEC, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark; Sino-Danish Centre for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, PR China; Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey; Institute of Marine Sciences, Middle East Technical University, 33731 Erdemli-Mersin, Turkey; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, PR China
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5
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Xue Y, Chen H, Xiao P, Jin L, Logares R, Yang J. Core taxa drive microeukaryotic community stability of a deep subtropical reservoir after complete mixing. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:769-782. [PMID: 37688478 PMCID: PMC10667671 DOI: 10.1111/1758-2229.13196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/17/2023] [Indexed: 09/11/2023]
Abstract
Microeukaryotes are key for predicting the change of ecosystem processes in the face of a disturbance. However, their vertical responses to multiple interconnected factors caused by water mixing remain unknown. Here, we conducted a 12-month high-frequency study to compare the impacts of mixing disturbances on microeukaryotic community structure and stability over different depths in a stratified reservoir. We demonstrate that core and satellite microeukaryotic compositions and interactions in surface waters were not resistant to water mixing, but significantly recovered. This was because the water temperature rebounded to the pre-mixing level. Core microeukaryotes maintained community stability in surface waters with high recovery capacity after water mixing. In contrast, the changes in water temperature, chlorophyll-a, and nutrients resulted in steep and prolonged variations in the bottom core and satellite microeukaryotic compositions and interactions. Under low environmental fluctuation, the recovery of microbial communities did not affect nutrient cycling in surface waters. Under high environmental fluctuation, core and satellite microeukaryotic compositions in bottom waters were significantly correlated with the multi-nutrient cycling index. Our findings shed light on different mechanisms of plankton community resilience in reservoir ecosystems to a major disturbance over depths, highlighting the role of bottom microeukaryotes in nutrient cycling.
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Affiliation(s)
- Yuanyuan Xue
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban EnvironmentChinese Academy of SciencesXiamenChina
| | - Huihuang Chen
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban EnvironmentChinese Academy of SciencesXiamenChina
- University of Chinese Academy of SciencesBeijingChina
| | - Peng Xiao
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban EnvironmentChinese Academy of SciencesXiamenChina
| | - Lei Jin
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban EnvironmentChinese Academy of SciencesXiamenChina
- University of Chinese Academy of SciencesBeijingChina
| | | | - Jun Yang
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban EnvironmentChinese Academy of SciencesXiamenChina
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Ping J, Cui E, Du Y, Wei N, Zhou J, Wang J, Niu S, Luo Y, Xia J. Enhanced causal effect of ecosystem photosynthesis on respiration during heatwaves. SCIENCE ADVANCES 2023; 9:eadi6395. [PMID: 37878695 PMCID: PMC10599625 DOI: 10.1126/sciadv.adi6395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/21/2023] [Indexed: 10/27/2023]
Abstract
Because of global warming, Earth's ecosystems have been experiencing more frequent and severe heatwaves. Heatwaves are expected to tip terrestrial carbon sequestration by elevating ecosystem respiration and suppressing gross primary productivity (GPP). Here, using the convergent cross-mapping technique, this study detected positive bidirectional causal effects between GPP and respiration in two unprecedented European heatwaves. Heatwaves enhanced the causal effect strength of GPP on respiration rather than respiration on GPP across 40 site-years of observations. Further analyses and global simulations revealed spatial heterogeneity in the heatwave response of the causal link strength between GPP and respiration, which was jointly driven by the local climate and vegetation properties. However, the causal effect strength of GPP on respiration showed considerable uncertainties in CMIP6 models. This study reveals an enhanced causal link strength between GPP and respiration during heatwaves, shedding light on improving projections for terrestrial carbon sink dynamics under future climate extremes.
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Affiliation(s)
- Jiaye Ping
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Erqian Cui
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Ying Du
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Ning Wei
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Jian Zhou
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Jing Wang
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yiqi Luo
- School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Jianyang Xia
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
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7
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Gonzalez A, Chase JM, O'Connor MI. A framework for the detection and attribution of biodiversity change. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220182. [PMID: 37246383 DOI: 10.1098/rstb.2022.0182] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/31/2023] [Indexed: 05/30/2023] Open
Abstract
The causes of biodiversity change are of great scientific interest and central to policy efforts aimed at meeting biodiversity targets. Changes in species diversity and high rates of compositional turnover have been reported worldwide. In many cases, trends in biodiversity are detected, but these trends are rarely causally attributed to possible drivers. A formal framework and guidelines for the detection and attribution of biodiversity change is needed. We propose an inferential framework to guide detection and attribution analyses, which identifies five steps-causal modelling, observation, estimation, detection and attribution-for robust attribution. This workflow provides evidence of biodiversity change in relation to hypothesized impacts of multiple potential drivers and can eliminate putative drivers from contention. The framework encourages a formal and reproducible statement of confidence about the role of drivers after robust methods for trend detection and attribution have been deployed. Confidence in trend attribution requires that data and analyses used in all steps of the framework follow best practices reducing uncertainty at each step. We illustrate these steps with examples. This framework could strengthen the bridge between biodiversity science and policy and support effective actions to halt biodiversity loss and the impacts this has on ecosystems. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.
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Affiliation(s)
- Andrew Gonzalez
- Department of Biology, McGill University, Montreal, Canada H3A 1B1
- Quebec Centre for Biodiversity Science, Montreal, Canada H3A 1B1
| | - Jonathan M Chase
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Mary I O'Connor
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver V6T 1Z4, Canada
- Santa Fe Institute, Santa Fe, NM 87501, USA
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8
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Zhang S, Pang Y, Xu H, Wei J, Jiang S, Pei H. Shift of phytoplankton assemblages in a temperate lake located on the eastern route of the South-to-North Water Diversion Project. ENVIRONMENTAL RESEARCH 2023; 227:115805. [PMID: 37004852 DOI: 10.1016/j.envres.2023.115805] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/08/2023]
Abstract
There remains no consensus on the effects of changes in the environment factors under the action of water diversions on phytoplankton communities. Herein the changing rules applying to phytoplankton communities subject to water diversion were unveiled based on long-term (2011-2021) time-series observations on Luoma Lake, located on the eastern route of the South-to-North Water Diversion Project. We found that nitrogen decreased and then increased, while phosphorus increased after operation of the water transfer project. Algal density and diversity were not affected by water diversion, while the duration of high algal density was shorter after water diversion. Phytoplankton composition had dramatic differences before and after water transfer. The phytoplankton communities exhibited greater fragility when they first experienced a human-mediated disturbance, and then they gradually adapted to more interferences and acquired stronger stability. We furthermore found the niche of Cyanobacteria narrowed while that of Euglenozoa widened under the pressure of water diversion. In addition to WT and DO, the main environmental factor before water diversion was NH4-N, whereas the effect of NO3-N and TN on phytoplankton communities increased after water diversion. These findings fill the knowledge gap as to the consequence of water diversion on water environments and phytoplankton communities.
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Affiliation(s)
- Shasha Zhang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Yiming Pang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Hangzhou Xu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China
| | - Jielin Wei
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Shan Jiang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Haiyan Pei
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China; Institute of Eco-Chongming (IEC), Shanghai, 202162, China.
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9
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Zhao Q, Van den Brink PJ, Xu C, Wang S, Clark AT, Karakoç C, Sugihara G, Widdicombe CE, Atkinson A, Matsuzaki SIS, Shinohara R, He S, Wang YXG, De Laender F. Relationships of temperature and biodiversity with stability of natural aquatic food webs. Nat Commun 2023; 14:3507. [PMID: 37316479 DOI: 10.1038/s41467-023-38977-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 05/22/2023] [Indexed: 06/16/2023] Open
Abstract
Temperature and biodiversity changes occur in concert, but their joint effects on ecological stability of natural food webs are unknown. Here, we assess these relationships in 19 planktonic food webs. We estimate stability as structural stability (using the volume contraction rate) and temporal stability (using the temporal variation of species abundances). Warmer temperatures were associated with lower structural and temporal stability, while biodiversity had no consistent effects on either stability property. While species richness was associated with lower structural stability and higher temporal stability, Simpson diversity was associated with higher temporal stability. The responses of structural stability were linked to disproportionate contributions from two trophic groups (predators and consumers), while the responses of temporal stability were linked both to synchrony of all species within the food web and distinctive contributions from three trophic groups (predators, consumers, and producers). Our results suggest that, in natural ecosystems, warmer temperatures can erode ecosystem stability, while biodiversity changes may not have consistent effects.
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Affiliation(s)
- Qinghua Zhao
- Aquatic Ecology and Water Quality Management Group, Wageningen University & Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.
- Research Unit of Environmental and Evolutionary Biology (URBE), University of Namur, Namur, Belgium.
- Institute of Complex Systems (naXys), University of Namur, Namur, Belgium.
- Institute of Life, Earth and the Environment (ILEE), University of Namur, Namur, Belgium.
| | - Paul J Van den Brink
- Aquatic Ecology and Water Quality Management Group, Wageningen University & Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
- Wageningen Environmental Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Chi Xu
- School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Shaopeng Wang
- Institute of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 100871, Beijing, China
| | - Adam T Clark
- Institute of Biology, University of Graz, Holteigasse 6, 8010, Graz, Austria
| | - Canan Karakoç
- Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN, 47405, USA
| | - George Sugihara
- Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA, USA
| | | | - Angus Atkinson
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL13DH, UK
| | | | | | - Shuiqing He
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Yingying X G Wang
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014, Jyväskylä, Finland
| | - Frederik De Laender
- Research Unit of Environmental and Evolutionary Biology (URBE), University of Namur, Namur, Belgium
- Institute of Complex Systems (naXys), University of Namur, Namur, Belgium
- Institute of Life, Earth and the Environment (ILEE), University of Namur, Namur, Belgium
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10
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Merz E, Saberski E, Gilarranz LJ, Isles PDF, Sugihara G, Berger C, Pomati F. Disruption of ecological networks in lakes by climate change and nutrient fluctuations. NATURE CLIMATE CHANGE 2023; 13:389-396. [PMID: 37038592 PMCID: PMC10079529 DOI: 10.1038/s41558-023-01615-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 01/24/2023] [Indexed: 06/19/2023]
Abstract
Climate change interacts with local processes to threaten biodiversity by disrupting the complex network of ecological interactions. While changes in network interactions drastically affect ecosystems, how ecological networks respond to climate change, in particular warming and nutrient supply fluctuations, is largely unknown. Here, using an equation-free modelling approach on monthly plankton community data in ten Swiss lakes, we show that the number and strength of plankton community interactions fluctuate and respond nonlinearly to water temperature and phosphorus. While lakes show system-specific responses, warming generally reduces network interactions, particularly under high phosphate levels. This network reorganization shifts trophic control of food webs, leading to consumers being controlled by resources. Small grazers and cyanobacteria emerge as sensitive indicators of changes in plankton networks. By exposing the outcomes of a complex interplay between environmental drivers, our results provide tools for studying and advancing our understanding of how climate change impacts entire ecological communities.
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Affiliation(s)
- Ewa Merz
- Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Erik Saberski
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA USA
| | - Luis J. Gilarranz
- Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Peter D. F. Isles
- Vermont Department of Environmental Conservation, Montpelier, VT USA
| | - George Sugihara
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA USA
| | - Christine Berger
- Stadt Zuerich, Wasserversorgung, Qualitaetsueberwachung, Zuerich, Switzerland
| | - Francesco Pomati
- Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
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11
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Decomposing predictability to identify dominant causal drivers in complex ecosystems. Proc Natl Acad Sci U S A 2022; 119:e2204405119. [PMID: 36215500 PMCID: PMC9586263 DOI: 10.1073/pnas.2204405119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ecosystems are complex systems of various physical, biological, and chemical processes. Since ecosystem dynamics are composed of a mixture of different levels of stochasticity and nonlinearity, handling these data is a challenge for existing methods of time series-based causal inferences. Here, we show that, by harnessing contemporary machine learning approaches, the concept of Granger causality can be effectively extended to the analysis of complex ecosystem time series and bridge the gap between dynamical and statistical approaches. The central idea is to use an ensemble of fast and highly predictive artificial neural networks to select a minimal set of variables that maximizes the prediction of a given variable. It enables decomposition of the relationship among variables through quantifying the contribution of an individual variable to the overall predictive performance. We show how our approach, EcohNet, can improve interaction network inference for a mesocosm experiment and simulated ecosystems. The application of the method to a long-term lake monitoring dataset yielded interpretable results on the drivers causing cyanobacteria blooms, which is a serious threat to ecological integrity and ecosystem services. Since performance of EcohNet is enhanced by its predictive capabilities, it also provides an optimized forecasting of overall components in ecosystems. EcohNet could be used to analyze complex and hybrid multivariate time series in many scientific areas not limited to ecosystems.
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12
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Chang CW, Miki T, Ye H, Souissi S, Adrian R, Anneville O, Agasild H, Ban S, Be'eri-Shlevin Y, Chiang YR, Feuchtmayr H, Gal G, Ichise S, Kagami M, Kumagai M, Liu X, Matsuzaki SIS, Manca MM, Nõges P, Piscia R, Rogora M, Shiah FK, Thackeray SJ, Widdicombe CE, Wu JT, Zohary T, Hsieh CH. Causal networks of phytoplankton diversity and biomass are modulated by environmental context. Nat Commun 2022; 13:1140. [PMID: 35241667 PMCID: PMC8894464 DOI: 10.1038/s41467-022-28761-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/11/2022] [Indexed: 11/21/2022] Open
Abstract
Untangling causal links and feedbacks among biodiversity, ecosystem functioning, and environmental factors is challenging due to their complex and context-dependent interactions (e.g., a nutrient-dependent relationship between diversity and biomass). Consequently, studies that only consider separable, unidirectional effects can produce divergent conclusions and equivocal ecological implications. To address this complexity, we use empirical dynamic modeling to assemble causal networks for 19 natural aquatic ecosystems (N24◦~N58◦) and quantified strengths of feedbacks among phytoplankton diversity, phytoplankton biomass, and environmental factors. Through a cross-system comparison, we identify macroecological patterns; in more diverse, oligotrophic ecosystems, biodiversity effects are more important than environmental effects (nutrients and temperature) as drivers of biomass. Furthermore, feedback strengths vary with productivity. In warm, productive systems, strong nitrate-mediated feedbacks usually prevail, whereas there are strong, phosphate-mediated feedbacks in cold, less productive systems. Our findings, based on recovered feedbacks, highlight the importance of a network view in future ecosystem management. Disentangling causal interactions among biodiversity, ecosystem functioning and environmental factors is key to understanding how ecosystems respond to changing environment. This study presents a global scale analysis quantifying causal interactions and feedbacks among phytoplankton diversity, biomass and nutrients along environmental gradients of aquatic ecosystems.
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Affiliation(s)
- Chun-Wei Chang
- National Center for Theoretical Sciences, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan
| | - Takeshi Miki
- Faculty of Advanced Science and Technology, Ryukoku University, Otsu, Shiga, 520-2194, Japan.,Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Center for Biodiversity Science, Ryukoku University, Otsu, Shiga, 520-2194, Japan
| | - Hao Ye
- Health Science Center Libraries, University of Florida, Gainesville, FL, 32611, USA
| | - Sami Souissi
- Univ. Lille, CNRS, Univ, Littoral Côte D'Opale, IRD, UMR 8187, LOG- Laboratoire D'Océanologie et de Géosciences, Station Marine de Wimereux, F- 59000, Lille, France
| | - Rita Adrian
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, IGB, 12587, Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, 14195, Berlin, Germany
| | - Orlane Anneville
- National Research Institute for Agriculture, Food and Environment (INRAE), CARRTEL, Université Savoie Mont Blanc, 74200, Thonon les Bains, France
| | - Helen Agasild
- Centre for Limnology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5D, 51014, Tartu, Estonia
| | - Syuhei Ban
- Department of Ecosystem Studies, School of Environmental Science, The University of Shiga Prefecture, Hikone, 522-8533, Shiga, Japan
| | - Yaron Be'eri-Shlevin
- Kinneret Limnological Laboratory, Israel Oceanographic & Limnological Research, P.O. Box 447, 14950, Migdal, Israel
| | - Yin-Ru Chiang
- Biodiversity Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Heidrun Feuchtmayr
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, Lancashire, LA1 4AP, UK
| | - Gideon Gal
- Kinneret Limnological Laboratory, Israel Oceanographic & Limnological Research, P.O. Box 447, 14950, Migdal, Israel
| | - Satoshi Ichise
- Lake Biwa Environmental Research Institute, Otsu, 520-0022, Japan
| | - Maiko Kagami
- Faculty of Environment and Information Sciences, Yokohama National University, Yokohama, 240-8502, Kanagawa, Japan.,Department of Environmental Science, Faculty of Science, Toho University, Funabashi, Chiba, 274-8510, Japan
| | - Michio Kumagai
- Lake Biwa Environmental Research Institute, Otsu, 520-0022, Japan.,Research Center for Lake Biwa & Environmental Innovation, Ritsumeikan University, Kusatsu, 525-0058, Shiga, Japan
| | - Xin Liu
- Department of Ecosystem Studies, School of Environmental Science, The University of Shiga Prefecture, Hikone, 522-8533, Shiga, Japan
| | - Shin-Ichiro S Matsuzaki
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Marina M Manca
- CNR Water Research Institute (IRSA), L.go Tonolli 50, 28922, Verbania, Pallanza, Italy
| | - Peeter Nõges
- Centre for Limnology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5D, 51014, Tartu, Estonia
| | - Roberta Piscia
- CNR Water Research Institute (IRSA), L.go Tonolli 50, 28922, Verbania, Pallanza, Italy
| | - Michela Rogora
- CNR Water Research Institute (IRSA), L.go Tonolli 50, 28922, Verbania, Pallanza, Italy
| | - Fuh-Kwo Shiah
- Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan
| | - Stephen J Thackeray
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, Lancashire, LA1 4AP, UK
| | | | - Jiunn-Tzong Wu
- Biodiversity Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Tamar Zohary
- Kinneret Limnological Laboratory, Israel Oceanographic & Limnological Research, P.O. Box 447, 14950, Migdal, Israel
| | - Chih-Hao Hsieh
- National Center for Theoretical Sciences, Taipei, 10617, Taiwan. .,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan. .,Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan. .,Institute of Ecology and Evolutionary Biology, Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan.
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13
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Abstract
It is often claimed that only experiments can support strong causal inferences and therefore they should be privileged in the behavioral sciences. We disagree. Overvaluing experiments results in their overuse both by researchers and decision makers and in an underappreciation of their shortcomings. Neglect of other methods often follows. Experiments can suggest whether X causes Y in a specific experimental setting; however, they often fail to elucidate either the mechanisms responsible for an effect or the strength of an effect in everyday natural settings. In this article, we consider two overarching issues. First, experiments have important limitations. We highlight problems with external, construct, statistical-conclusion, and internal validity; replicability; and conceptual issues associated with simple X causes Y thinking. Second, quasi-experimental and nonexperimental methods are absolutely essential. As well as themselves estimating causal effects, these other methods can provide information and understanding that goes beyond that provided by experiments. A research program progresses best when experiments are not treated as privileged but instead are combined with these other methods.
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Affiliation(s)
- Ed Diener
- Department of Psychology, University of Utah.,Department of Psychology, University of Virginia.,Gallup, Washington, D.C
| | - Robert Northcott
- Department of Philosophy, Birkbeck College, University of London
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14
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Ye L, Tan L, Wu X, Cai Q, Li BL. Nonlinear causal analysis reveals an effective water level regulation approach for phytoplankton blooms controlling in reservoirs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150948. [PMID: 34655635 DOI: 10.1016/j.scitotenv.2021.150948] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/02/2021] [Accepted: 10/09/2021] [Indexed: 06/13/2023]
Abstract
Reservoirs are a rapidly increasing water body providing water supply, irrigation, and many other benefits for human societies globally. However, due to changes in hydrological conditions, building reservoirs tends to bring adverse effects such as eutrophication and phytoplankton blooms, reducing the ecosystem service values. This study focuses on using the empirical dynamic modeling (EDM), an emerging approach for nonlinear analysis, to investigate the nonlinear causal relationship of water level fluctuation (WLF) on phytoplankton biomass and then develop a quantitative model guiding effective phytoplankton blooms controlling based on water level regulations in reservoirs. Specifically, with 9-year continued daily observed data in the Three Gorges Reservoir, we examined the causal effects of different WLF parameters on the dynamics of phytoplankton blooms for the first time. We found that the water level change in the past 24 h (ΔWL) has the strongest causal effect on the daily dynamics of phytoplankton biomass among all WLF parameters (ΔWL, |ΔWL|, and the water level), with a time lag of 2 days. Moreover, EDM revealed a nonlinear relationship between ΔWL and daily dynamics of phytoplankton biomass and achieved a successful prediction for the chlorophyll a concentration 2-day ahead. Further scenario analyses found that both the rise and fall of water level will significantly reduce the chlorophyll a concentration when phytoplankton blooms occur. Nevertheless, on the whole, the rising water level has a more substantial effect on phytoplankton blooms than falling the water level. This result reveals that regulating ΔWL is a simple and effective approach in controlling phytoplankton blooms in reservoirs. Our study reported the nonlinear causal effect of ΔWL on the dynamics of chlorophyll a and provided a quantitative approach guiding effective phytoplankton blooms controlling based on the water level regulation, which might have a broad application in algal blooms controlling in reservoirs and similar waterbodies.
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Affiliation(s)
- Lin Ye
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Lu Tan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xinghua Wu
- China Three Gorges Corporation, Beijing 100038, China
| | - Qinghua Cai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - B Larry Li
- Ecological Complexity and Modeling Laboratory, University of California at Riverside, Riverside, CA 92521-0124, USA
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15
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Chang CW, Miki T, Ushio M, Ke PJ, Lu HP, Shiah FK, Hsieh CH. Reconstructing large interaction networks from empirical time series data. Ecol Lett 2021; 24:2763-2774. [PMID: 34601794 DOI: 10.1111/ele.13897] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 09/03/2021] [Indexed: 01/03/2023]
Abstract
Reconstructing interactions from observational data is a critical need for investigating natural biological networks, wherein network dimensionality is usually high. However, these pose a challenge to existing methods that can quantify only small interaction networks. Here, we proposed a novel approach to reconstruct high-dimensional interaction Jacobian networks using empirical time series without specific model assumptions. This method, named "multiview distance regularised S-map," generalised the state space reconstruction to accommodate high dimensionality and overcome difficulties in quantifying massive interactions with limited data. When evaluating this method using time series generated from theoretical models involving hundreds of interacting species, estimated strengths of interaction Jacobians were in good agreement with theoretical expectations. Applying this method to a natural bacterial community helped identify important species from the interaction network and revealed mechanisms governing the dynamical stability of a bacterial community. The proposed method overcame the challenge of high dimensionality in large natural dynamical systems.
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Affiliation(s)
- Chun-Wei Chang
- National Center for Theoretical Sciences, Taipei, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
| | - Takeshi Miki
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan.,Faculty of Advanced Science and Technology, Ryukoku University, Otsu, Japan.,Center for Biodiversity Science, Ryukoku University, Otsu, Japan
| | - Masayuki Ushio
- Hakubi Center, Kyoto University, Kyoto, Japan.,Center for Ecological Research, Kyoto University, Otsu, Japan
| | - Po-Ju Ke
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA.,Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Pei Lu
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Fuh-Kwo Shiah
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan.,Institute of Oceanography, National Taiwan University, Taipei, Taiwan
| | - Chih-Hao Hsieh
- National Center for Theoretical Sciences, Taipei, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan.,Institute of Oceanography, National Taiwan University, Taipei, Taiwan.,Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, Taiwan
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16
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Li X, Li F, Zou G, Feng C, Sha H, Liu S, Liang H. Physiological responses and molecular strategies in heart of silver carp (Hypophthalmichthys molitrix) under hypoxia and reoxygenation. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 40:100908. [PMID: 34482099 DOI: 10.1016/j.cbd.2021.100908] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/21/2021] [Accepted: 08/22/2021] [Indexed: 12/20/2022]
Abstract
A sufficient oxygen concentration is essential for fish growth, reproduction, and metabolism. Silver carp (Hypophthalmichthys molitrix) is sometimes challenged by hypoxia during intensive aquaculture or because of environmental changes. However, the response to hypoxic stress in the heart of silver carp remains relatively unknown. In the present study, we reported the effects of hypoxia on histological structures, enzyme activities, and gene expression in the heart of silver carp. Hematoxylin and eosin (H&E) staining of heart sections showed that the myocardial fibers gradually became disordered, swollen, and even ruptured during hypoxic treatment. These phenotypes were also supported by increased activities of injury-related enzymes. Moreover, the transcriptome was analyzed to determine the molecular strategies of hypoxia adaptation in the heart. PI3K-Akt signaling pathway, FoxO signaling pathway, and JAK-STAT signaling pathway were the most prominent pathways activated by hypoxia. Twenty significantly differentially expressed genes were selected to create a network diagram related to cell proliferation, carbohydrate metabolism, oxidative stress, and angiogenesis. Additionally, reoxygenation could ameliorate cardiac injury and eliminate the effects of hypoxia on gene expression. This was the first comparative transcriptomic study to explore the molecular mechanism of the response to hypoxia and reoxygenation in the heart of silver carp. Our results provide a theoretical basis for cultivating hypoxia-tolerant carp varieties in the future.
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Affiliation(s)
- Xiaohui Li
- Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries, Wuhan 430223, China
| | - Fei Li
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture and Rural Affairs, Key Laboratory of Freshwater Aquaculture Genetic and Breeding of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou 313001, China
| | - Guiwei Zou
- Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries, Wuhan 430223, China
| | - Cui Feng
- Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries, Wuhan 430223, China
| | - Hang Sha
- Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries, Wuhan 430223, China
| | - Shili Liu
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture and Rural Affairs, Key Laboratory of Freshwater Aquaculture Genetic and Breeding of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou 313001, China
| | - Hongwei Liang
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries Science, Wuhan 430223, China; Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries, Wuhan 430223, China.
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17
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Promotion of the Development of Sentinel Species in the Water Column: Example Using Body Size and Fecundity of the Egg-Bearing Calanoid Copepod Eurytemora affinis. WATER 2021. [DOI: 10.3390/w13111442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The development of sentinel species in aquatic ecosystems is mostly based on benthic organisms; however, organisms living in water column such as zooplankton have received less attention, except for some cladocerans. In this paper, a new ecological indicator based on simple measurements of the size and fecundity of egg-bearing calanoid copepods is developed. The well-studied estuarine copepod Eurytemora affinis is used to illustrate this new framework. A large database obtained from laboratory experiments developed under different conditions is used to define a reference regression line between clutch size (CS) and prosome length (PL). The same database allowed one to confirm that the coefficient of variation (CV) of CS is an adequate estimator of the accumulated stress at population level. The CV of PL shows very little variability in all experimental and field conditions. The values of CS and PL obtained from the Seine, Loire, Gironde, Scheldt and Elbe estuaries in Europe are compared to the reference regression line. A quality index (QI) is calculated as a percentage of difference between the observed and the predicted CS. The QI classified 19 samples collected in the Seine estuary between 2004 and 2010 into four classes according to the physiological condition of the copepod female. A single sampling from June 2004 (5.26%) showed a very good condition, whereas 57.9% of the sampling dates confirmed good conditions. On the other hand, four sampling dates were associated to very bad conditions and three sampling dates indicated bad conditions. Seven additional samples obtained from other European estuaries between 2006 and 2009 were also used. Females showing poor conditions were observed in the early spring of 2005 and 2008 as well as during the month of November. These years were characterized by very strong climatic anomalies with a very cold late winter in 2005 and a warm winter in 2008. Therefore, it seems that the QI perfectly reflected the strong stress caused by the sudden change in hydro-climatic conditions that have certainly affected the physiology of copepod females and probably the availability of food. The new indicator is very simple to calculate and can be generalised to several aquatic ecosystems (fresh water and brackish water) by targeting the dominating egg-bearing calanoid copepods. As in the case of E. affinis, the development of sentinel species based on copepods or cladocerans can enrich ecological and ecotoxicological studies given their capacity to integrate the variability of their habitats’ quality at the individual and population levels.
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