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Wen Y, Su X, Cai F, Qian R, Bejarano MD, Wu S, Yang Q, Liu X, Zeng B. The differences in plant invasion in two types of shorelines under flow regulation of the Three Gorges Reservoir. Sci Total Environ 2024; 912:168892. [PMID: 38029974 DOI: 10.1016/j.scitotenv.2023.168892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/18/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023]
Abstract
Riparian zones, crucial for linking fluvial and terrestrial habitats, are among the most diverse ecosystems. However, they are intensively invaded by alien plants, particularly in dam-regulated rivers. Therefore, understanding the mechanisms underlying plant invasion in dam-regulated river systems has become increasingly important, given that over two-thirds of global rivers are artificially regulated. Regulated rivers may flood upland areas or pristine riparian zones, resulting in shorelines developed from pre-upland and pre-riparian areas. However, differences in invasion intensities, adaptive strategies of invasive plants, and native species' resistance (namely the diversity-invasibility relationship) across these shorelines are unclear. To address these uncertainties, we performed field investigations in the Three Gorges Reservoir (TGR) on the upper Yangtze River, where both pre-upland and pre-riparian shorelines are present. Our findings indicate that pre-upland shorelines are more intensively invaded, showing higher relative richness and cover of invasive species. Invasive plants in this area displayed more conservative resource strategies and greater drought tolerance, exhibiting lower community-weighted mean (CWM) specific leaf area, higher CWM leaf dry mass content, and larger CWM seed mass. Pre-upland shorelines' invasibility decreased as the richness and cover of native species increased, a trend not observed in pre-riparian shorelines. The observed variations in plant invasion between the two shoreline types are primarily driven by differences in resident plant presence, soil moisture levels, and hydrological disturbances. This study provides valuable insights for policymakers and practitioners involved in managing invasive plants in regulated river ecosystems.
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Affiliation(s)
- Yi Wen
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Xiaolei Su
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China.
| | - Fu Cai
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Rongyan Qian
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - María Dolores Bejarano
- Department of Natural Systems and Resources, Universidad Politécnica de Madrid, Madrid, Spain
| | - Shan Wu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Qin Yang
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Xudong Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Bo Zeng
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China.
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Khurram D, Bao Y, Tang Q, He X, Li J, de D Nambajimana J, Nsabimana G. Sedimentary geochemistry mediated by a specific hydrological regime in the water level fluctuation zone of the Three Gorges Reservoir, China. Environ Sci Pollut Res Int 2023; 30:40356-40374. [PMID: 36609973 DOI: 10.1007/s11356-022-25086-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The water level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) acts as an important sink for inflowing suspended sediment loads over the inundation periods following regular dam operations. This study depicts the sedimentary geochemical dynamics along a sedimentary profile based on the determined chronology and explores its links to the specific hydrological regime created by dam flow regulation and riverine seasonal suspended sediment dynamics. A compact 345-cm-long sediment core was extracted near the base water level (145.3 m) from the WLFZ of the TGR and sectioned at 5-cm intervals. Extracted sediment subsamples were analyzed for grain size composition, organic matter (OM), total nitrogen (TN), and geochemical elements (Na, K, Ca, Mg, Pb, Zn, Ni, Co, Mn, Cr, Fe, and Cu). The sediment core chronology was determined using 137Cs elemental analysis. Sedimentary geochemistry and grain size properties of extracted sediment core exhibited greater variations during initial submergence years till the first complete impoundment of the TGR (2006-2010). Afterward (2011-2013), although upstream inflowing suspended sediments and reservoir water level were comparable, sediment deposition and concentrations of sedimentary geochemical constituents showed considerably fewer variations. Seasonal variations in sediment deposition and geochemical composition were also observed during the rainy (October-April) and dry (May-September) seasons, in addition to annual variations. Grain size, OM, and other sediment geochemical constituents all had significant correlations with each other and with sediment core depth. The concentrations of geochemical elements in various sediment stratigraphic layers exhibited staggering associations with each other and were dependent on each other in several ways. The arrangement of geochemical elements in various stratigraphic layers of the extracted core illustrated amalgamation with inputs from upstream seasonal suspended sediment dynamics and reservoir water levels. During shortened submergence periods and higher input sediment loads, geochemical elements demonstrated impulsive distributions. Alternatively, during longer submergence periods, elemental distributions were relatively uniform attributed to higher settling time to deposit according to grain size and geochemical affinities. Higher suspended sediment loads in association with seasonal floods also resulted in rough sediment deposition patterns, imparting variations in the distributions of geochemical elements. Interim mediations in geochemical element concentrations are associated with seasonal distal flash floods and local terrace bank collapses, which generate significant amounts of distal sediment loads that are quickly deposited and are not sorted hydrodynamically. Overall, although a specific mechanism was devised to circumvent the siltation process, a considerable amount of sediment is trapped at pre-dam sites. In addition, siltation caused nutrients and geochemical elements' enrichment.
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Affiliation(s)
- Dil Khurram
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuhai Bao
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, China
| | - Qiang Tang
- Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station, School of Geographical Sciences, Southwest University, Chongqing, 400715, China.
| | - Xiubin He
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, China
| | - Jinlin Li
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Jean de D Nambajimana
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gratien Nsabimana
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610299, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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Albright A, Fry BC, Verticchio A, Siesky B, Harris A, Arciero J. Metabolic blood flow regulation in a hybrid model of the human retinal microcirculation. Math Biosci 2023; 357:108969. [PMID: 36702235 PMCID: PMC10015448 DOI: 10.1016/j.mbs.2023.108969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/17/2023] [Accepted: 01/17/2023] [Indexed: 01/25/2023]
Abstract
The retinal vascular network supplies perfusion to vital visual structures, including retinal ganglion cells responsible for vision. Impairments in retinal blood flow and oxygenation are involved in the progression of many ocular diseases, including glaucoma. In this study, an established theoretical hybrid model of a retinal microvascular network is extended to include the effects of local blood flow regulation on oxygenation. A heterogeneous representation of the arterioles based on confocal microscopy images is combined with a compartmental description of the downstream capillaries and venules. A Green's function method is used to simulate oxygen transport in the arterioles, and a Krogh cylinder model is applied to the capillary and venular compartments. Acute blood flow regulation is simulated in response to changes in pressure, shear stress, and metabolism. Model results predict that both increased intraocular pressure and impairment of blood flow regulation can cause decreased tissue oxygenation, indicating that both mechanisms represent factors that could lead to impaired oxygenation characteristic of ocular disease. Results also indicate that the metabolic response mechanism reduces the fraction of poorly oxygenated tissue but that the pressure- and shear stress-dependent response mechanisms may hinder the vascular response to changes in oxygenation. Importantly, the heterogeneity of the vascular network demonstrates that traditionally reported average values of tissue oxygen levels hide significant localized defects in tissue oxygenation that may be involved in disease processes, including glaucoma. Ultimately, the model framework presented in this study will facilitate future comparisons to sectorial-specific clinical data to better assess the role of impaired blood flow regulation in ocular disease.
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Affiliation(s)
- Amanda Albright
- Department of Mathematical Sciences, Indiana University-Purdue University Indianapolis, 402 N. Blackford St, LD 270, Indianapolis, IN 46202, USA
| | - Brendan C Fry
- Department of Mathematics and Statistics, Metropolitan State University of Denver, P.O. Box 173362, Campus Box 38, Denver, CO 80217, USA
| | - Alice Verticchio
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, One Gustave L. Levy Place, Box 1183, New York, NY 10029, USA
| | - Brent Siesky
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, One Gustave L. Levy Place, Box 1183, New York, NY 10029, USA
| | - Alon Harris
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, One Gustave L. Levy Place, Box 1183, New York, NY 10029, USA
| | - Julia Arciero
- Department of Mathematical Sciences, Indiana University-Purdue University Indianapolis, 402 N. Blackford St, LD 270, Indianapolis, IN 46202, USA.
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Canning AD, Smart JCR, Dyke J, Curwen G, Hasan S, Waltham NJ. Constructed Wetlands Suitability for Sugarcane Profitability, Freshwater Biodiversity and Ecosystem Services. Environ Manage 2023; 71:304-320. [PMID: 36269373 PMCID: PMC9892086 DOI: 10.1007/s00267-022-01734-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Freshwater ecosystems, such as wetlands, are among the most impacted by agricultural expansion and intensification through extensive drainage and pollution. There is a pressing need to identify ways of managing agricultural landscapes to ensure food and water security without jeopardising biodiversity and other environmental benefits. Here we examine the potential fish biodiversity and landholder financial benefits arising from the integration of constructed lagoons to improve drainage, flow regulation and habitat connectivity within a sugarcane dominated catchment in north Queensland, Australia. A hybrid approach was used, combining the findings of both fish ecological surveys and a financial cost-benefit analysis. We found that the constructed lagoons supported at least 36 native freshwater fishes (over half of all native freshwater fishes in the region), owing to their depth, vegetated margins, moderate water quality and high connectivity to the Tully River. In addition to biodiversity benefits, we estimated that surrounding sugarcane farms would have financially benefited from reduced flooding of cropland and the elevation of low-lying cropland with deposited spoil excavated from lagoon construction. Improved drainage and flow regulation allowed for improvement in sugarcane yield and elevated land increased gross margins from extending the length of the cane production cycle or enabling a switch from cattle grazing to cane production. Restoring or creating wetlands to reduce flooding in flood-prone catchments is a globally applicable model that could improve both agricultural productivity and aquatic biodiversity, while potentially increasing farm income by attracting payments for provision of ecosystem services.
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Affiliation(s)
- Adam D Canning
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, 1 James Cook Drive, Townsville, Queensland, 4811, Australia.
| | - James C R Smart
- School of Environment and Science, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111, Australia
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111, Australia
| | - Joshua Dyke
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111, Australia
| | - Graeme Curwen
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111, Australia
| | - Syezlin Hasan
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, Queensland, 4111, Australia
| | - Nathan J Waltham
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, 1 James Cook Drive, Townsville, Queensland, 4811, Australia
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Bai Y, Zhang S, Mu E, Zhao Y, Cheng L, Zhu Y, Yuan Y, Wang Y, Ding A. Characterizing the spatiotemporal distribution of dissolved organic matter (DOM) in the Yongding River Basin: Insights from flow regulation. J Environ Manage 2023; 325:116476. [PMID: 36323113 DOI: 10.1016/j.jenvman.2022.116476] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/26/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Artificial flow regulation is an important measure to alleviate water shortages and improve the ecological quality of river basins. Dissolved organic matter (DOM) plays a crucial role in the carbon cycle and regulates biogeochemical and ecological processes in aquatic systems. Among the numerous studies on the effects of anthropogenic activities on the quality and quantity of river DOM, few studies have focused on the influence of different artificially regulated flow on the composition, source, and fate of fluvial DOM. This study aims to elucidate the impact of different artificial regulation modes of river flows on the source, migration, and transformation of DOM. The optical properties of DOM were used to explore the temporal and spatial distribution characteristics of DOM in the Yongding River Basin, where artificial regulation of river flows by cross-basin and inner-basin water transfers were implemented. Excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis revealed four fluorescent substances of DOM in the water: one microbial humic-like (C1), one terrestrial humic-like (C2), one non-point source pollution humic-like (C4), and one tryptophan-like (C3) substance. Due to cross-basin water transfer from the Yellow River, the flow is the highest (21.79 m3/s) during spring, which was the reason that the signal of C2 was stronger during spring (71.45 QSU) compared to summer (57.12 QSU) and autumn (51.78 QSU). Due to inner-basin water transfer from upstream reservoirs, C3 derived from autochthonous sources were higher during autumn (130.81 QSU) than during spring (77.17 QSU) and summer (93.16 QSU). With no water transfer, more C1 were present at higher temperatures during summer (141.51 QSU) than during spring (126.73 QSU) and autumn (128.8 QSU). Moreover, C4 originating from urban and/or agricultural non-point source runoff increased during summer (57.07 QSU) than during spring (33.29 QSU) and autumn (52.27 QSU) because of increased rainfall. The different modes of artificial regulation of river flows changed the hydrological characteristics of the basin, which in turn altered the temporal and spatial distribution characteristics of the quantity and quality of DOM. The finding of this study can help promote the development of appropriate management strategies for artificial regulation of river flows in the basin. Furthermore, this study provides a basis for investigating the effects of different artificial flow regulations on the carbon cycles and ecological risks of rivers in the basin.
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Affiliation(s)
- Yijuan Bai
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Shurong Zhang
- Institute of Land Surface System and Sustainable Development, Faculty of Geographical Science, Beijing Normal University, Beijing, 100875, China; State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, 100875, China.
| | - Enlin Mu
- Water Resources Management Center of Ministry of Water Resources, Beijing, 100038, China
| | - Yinjun Zhao
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Nanning Normal University, Nanning, 530001, China
| | - Lirong Cheng
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yi Zhu
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yumin Yuan
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yingying Wang
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
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Fan L, Sun Y, Choy JS, Kassab GS, Lee LC. Mechanism of exercise intolerance in heart diseases predicted by a computer model of myocardial demand-supply feedback system. Comput Methods Programs Biomed 2022; 227:107188. [PMID: 36334525 DOI: 10.1016/j.cmpb.2022.107188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/28/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE The myocardial demand-supply feedback system plays an important role in augmenting blood supply in response to exercise-induced increased myocardial demand. During this feedback process, the myocardium and coronary blood flow interact bidirectionally at many different levels. METHODS To investigate these interactions, a novel computational framework that considers the closed myocardial demand-supply feedback system was developed. In the framework coupling the systemic circulation of the left ventricle and coronary perfusion with regulation, myocardial work affects coronary perfusion via flow regulation mechanisms (e.g., metabolic regulation) and myocardial-vessel interactions, whereas coronary perfusion affects myocardial contractility in a closed feedback system. The framework was calibrated based on the measurements from healthy subjects under graded exercise conditions, and then was applied to simulate the effects of graded exercise on myocardial demand-supply under different physiological and pathological conditions. RESULTS We found that the framework can recapitulate key features found during exercise in clinical and animal studies. We showed that myocardial blood flow is increased but maximum hyperemia is reduced during exercise, which led to a reduction in coronary flow reserve. For coronary stenosis and myocardial inefficiency, the model predicts that an increase in heart rate is necessary to maintain the baseline cardiac output. Correspondingly, the resting coronary flow reserve is exhausted and the range of heart rate before exhaustion of coronary flow reserve is reduced. In the presence of metabolic regulation dysfunction, the model predicts that the metabolic vasodilator signal is higher at rest, saturates faster during exercise, and as a result, causes quicker exhaustion of coronary flow reserve. CONCLUSIONS Model predictions showed that the coronary flow reserve deteriorates faster during graded exercise, which in turn, suggests a decrease in exercise tolerance for patients with stenosis, myocardial inefficiency and metabolic flow regulation dysfunction. The findings in this study may have clinical implications in diagnosing cardiovascular diseases.
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Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Yuexing Sun
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, CA, USA
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
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Liu X, Xu Q. Hydropeaking impacts on riverine plants downstream from the world's largest hydropower dam, the Three Gorges Dam. Sci Total Environ 2022; 845:157137. [PMID: 35803426 DOI: 10.1016/j.scitotenv.2022.157137] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Hydropeaking has become a global issue because of extensive hydropower dam construction worldwide. Yet, its ecological impacts on riverine ecosystems are not well studied. We explored the effects of hydropeaking on riverine plants, based on data from a ~300 km reach downstream of the world's largest hydropower dam, the Three Gorges Dam. We tested three hypotheses relating to hydropeaking impacts on species elevational distributions, assemblage structure and species-specific biomass patterns by generalized linear mixed modelling and joint species distribution modelling. We found that, first, hydropeaking greatly shaped species elevational ranges, leading to expansions of herbs to high elevations and shifting species dominance at low elevations. Secondly, we detected contrasting effects of hydropeaking on assemblage-level characteristics of herbs. The inundation induced by hydropeaking had strong effects on assemblage composition and biomass allocation, where more biomass was allocated to belowground part. Hydropeaking blurred the species richness-biomass relationship, although it had little effect on species richness or plot-level biomass. Thirdly, hydropeaking induced inundation was the most important covariate driving species biomass patterns of riverine plants, although complex species-specific effects were identified, and random effects were often large in fitted models. We concluded that hydropeaking likely acted as a major driver of plant community assembly in rivers with a hydropower dam. Conservation and restoration of riverine plants can benefit from the inclusion of water level management in operational schemes of hydropower dams, especially during the early life history stages.
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Affiliation(s)
- Xueqin Liu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China.
| | - Qiangqiang Xu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
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Elgueta A, Górski K, Thoms M, Fierro P, Toledo B, Manosalva A, Habit E. Interplay of geomorphology and hydrology drives macroinvertebrate assemblage responses to hydropeaking. Sci Total Environ 2021; 768:144262. [PMID: 33453538 DOI: 10.1016/j.scitotenv.2020.144262] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/28/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Hydropeaking leads to major anthropogenic disturbance of river networks worldwide. Flow variations imposed by hydropeaking may significantly affect macroinvertebrate assemblages within the river network. As such, the responses of macroinvertebrate assemblages to hydropeaking are expected to be complex and vary across spatial and temporal scales as well as ecological organization levels. To unpack this complexity, we assessed the interplay of geomorphic and hydrological variables as drivers of the responses of macroinvertebrate assemblages to hydropeaking. Specifically, we studied different levels of ecological organization of macroinvertebrate assemblages in two functional process zones (FPZs; Sub-Andean and Central Valley Gravel Dominated) subjected to different flow management in two Chilean Andean river networks. Hydropeaking caused significant reduction of macroinvertebrate abundances in both FPZs and at all ecological organization levels with the exception of one feeding guild (scrapers). Furthermore, the response of macroinvertebrate assemblage variance was stronger in the Central Valley Gravel Dominated FPZ. Both geomorphic and hydrological variables influenced macroinvertebrate assemblage responses. However, the effects of the principal geomorphic variables operated at valley (meso) spatial scale and the main hydrological variables operated at the sub-daily (micro) temporal scale. Therefore, to minimise the effects of hydropeaking on macroinvertebrate assemblages, flow management should consider reduction of sub-daily variability. Furthermore, placement of new barriers should take into account not only their position within the river network but also their effects downstream that strongly depend on characteristics of river valley.
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Affiliation(s)
- Anaysa Elgueta
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, Concepción, Chile.
| | - Konrad Górski
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Departamento de Ecología, Facultad de Ciencias y Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile.
| | - Martin Thoms
- Riverine Landscapes Research Laboratory, University of New England, NSW, Australia.
| | - Pablo Fierro
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
| | - Bárbara Toledo
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, Concepción, Chile
| | - Aliro Manosalva
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, Concepción, Chile.
| | - Evelyn Habit
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, Concepción, Chile; Centro de Ciencias Ambientales EULA, Universidad de Concepción, Concepción, Chile.
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9
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Janssen P, Stella JC, Räpple B, Gruel CR, Seignemartin G, Pont B, Dufour S, Piégay H. Long-term river management legacies strongly alter riparian forest attributes and constrain restoration strategies along a large, multi-use river. J Environ Manage 2021; 279:111630. [PMID: 33213995 DOI: 10.1016/j.jenvman.2020.111630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Many terrestrial ecosystems have undergone profound transformation under the pressure of multiple human stressors. This may have oriented altered ecosystems toward transient or new states. Understanding how these cumulative impacts influence ecosystem functions, services and ecological trajectories is therefore essential to defining effective restoration strategies. This is particularly the case in riverine ecosystems, where the profound alteration of natural disturbance regimes can make the effectiveness of restoration operations questionable. Using the case study of legacy dike fields, i.e., area delimited by longitudinal and lateral dikes, along the regulated Rhône River, we studied the impacts of long-term channelization and flow regulation on environmental conditions and riparian forests attributes along a 200 km climatic gradient. We characterized the imprint of human stressors on these forests by comparing the dike field stands to more natural stands in both young and mature vegetation stages. Across four reaches of the river between Lyon and the Mediterranean Sea, we found that channelization consistently promoted high rate of overbank sedimentation and rapid disconnection of dike field surfaces from the channel. The rapid terrestrialisation of dike field surfaces, i.e., the process by which former aquatic areas transition to a terrestrial ecosystem as a result of dewatering or sedimentation, fostered a pulse of riparian forest regeneration in these resource-rich environments that differs from more natural sites in structure and composition. Within the dike fields, older pre-dam stands are dominated by post-pioneer and exotic species, and post-dam stands support large, aging pioneer trees with a largely exotic understory regeneration layer. These patterns were associated with differences in the relative surface elevation among dike fields, whereas species shifts generally followed the river's longitudinal climate gradient. To enhance the functionality of these human-made ecosystems, restoration strategies should target the reconnection of dike fields to the river by dismantling part of the dikes to promote lateral erosion, forest initiation and community succession, as well as increasing minimum flows in channels to improve connection with groundwater. However, since a river-wide return to a pre-disturbance state is very unlikely, a pragmatic approach should be favoured, focusing on local actions that can improve abiotic and biotic function, and ultimately enhancing ecosystem services such biodiversity, habitat, and recreation opportunities.
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Affiliation(s)
- Philippe Janssen
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France; Univ. Grenoble Alpes, INRAE, LESSEM, St-Martin-d'Hères, France.
| | - John C Stella
- Department of Sustainable Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA.
| | - Bianca Räpple
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France.
| | - Charles-Robin Gruel
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France; Asian School of the Environment, Nanyang Technological University, Singapore.
| | | | - Bernard Pont
- Réserves Naturelles de France, Quétigny, France.
| | | | - Hervé Piégay
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France.
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10
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García de Jalón S, González Del Tánago M, García de Jalón D. A new approach for assessing natural patterns of flow variability and hydrological alterations: The case of the Spanish rivers. J Environ Manage 2019; 233:200-210. [PMID: 30580116 DOI: 10.1016/j.jenvman.2018.12.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/06/2018] [Accepted: 12/16/2018] [Indexed: 06/09/2023]
Abstract
Ensuring water is available for human use usually requires dams and reservoirs that severely affect river ecosystems. Hydrological alteration by river damming represents one of the most prominent human impacts on freshwater ecosystems. This paper presents a methodological approach to assessing the natural patterns of flow variability and hydrological alterations in Mediterranean rivers. The methodology first defines the admissible range of flow variability under a natural flow regime. Then, the methodology measures the environmental impact of flow regulation according to the inferred hydrological alteration and classifies rivers into homogeneous groups according to the magnitude, frequency, duration and seasonality of the impacts. This paper applies the proposed methodology to thirty-three river segments below large reservoirs located in the three largest Spanish watersheds (Duero, Ebro and Tajo). For each segment, this study evaluates the general impoundment characteristics and geographical contexts and calculates the flow impacts and the divergence between the circulating flows and the reference area of admissible flow variability on a daily basis for the period 2000-2010. This assessment of dam regulation impacts provides a reference to plan measures for mitigating these impacts. The advantages of this flow regulation impact analysis over other analyses are discussed in terms of the implementation of environmental water costs as suggested by the European Water Framework Directive. This approach expands the current understanding of water environmental costs and represents a practical management tool for decreasing the environmental impacts of flow regulation and for increasing water-use efficiency.
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Affiliation(s)
- Silvestre García de Jalón
- Basque Centre for Climate Change - BC3, Building 1, 1st Floor, Scientific Campus of the University of the Basque Country, Barrio Sarriena, s/n, 48940, Leioa, Bizkaia, Spain.
| | - Marta González Del Tánago
- Department of Natural Resources and Systems, Universidad Politécnica de Madrid, E.T.S.I. Montes, Forestal y del Medio Natural, 28040, Madrid, Spain
| | - Diego García de Jalón
- Department of Natural Resources and Systems, Universidad Politécnica de Madrid, E.T.S.I. Montes, Forestal y del Medio Natural, 28040, Madrid, Spain
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11
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Bing H, Wu Y, Zhou J, Sun H, Wang X, Zhu H. Spatial variation of heavy metal contamination in the riparian sediments after two-year flow regulation in the Three Gorges Reservoir, China. Sci Total Environ 2019; 649:1004-1016. [PMID: 30308875 DOI: 10.1016/j.scitotenv.2018.08.401] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/25/2018] [Accepted: 08/27/2018] [Indexed: 05/16/2023]
Abstract
Regular impoundment of the Three Gorges Reservoir (TGR) with intensified human activities in the watershed imparts a significant effect on the environmental changes in the riparian zone. In this study, six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the riparian sediments of the entire TGR mainstream were investigated in 2014 and 2016 to identify their contamination and risk characteristics and decipher the main factors for the variation of the metal contamination. The results showed that the concentrations of the heavy metals in the sediments did not vary significantly between 2014 and 2016, and their contamination degrees decreased in the order of Cd> > Cu ≈ Zn > Pb > Cr ≈ Ni in 2014 and Cd> > Zn > Cu ≈ Pb > Cr ≈ Ni in 2016. The potential eco-risk of Cd was extremely high in the two years, while the eco-risk of other metals was very low. The sediments showed a moderate to high contamination level, a high potential eco-risk but a low toxic risk to aquatic biota in the two years. Spatially, the contamination and risk levels of heavy metals were relatively higher in the downstream TGR region in 2014 except for the sites close to the urban areas but in the upper-middle TGR region in 2016. Increasing anthropogenic influence contributed to the high contamination and risk levels of Cd, Cu, Pb and Zn in the upper-middle region in 2016. The results indicated that the Cd contamination in the riparian sediments of the TGR was still a vital environmental issue, and the decreased sediment inputs from the upstream major tributaries, the periodic and anti-seasonal flow regulation, local geomorphological characteristics and anthropogenic activities determined the contamination distribution of heavy metals in the riparian sediments.
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Affiliation(s)
- Haijian Bing
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Yanhong Wu
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
| | - Jun Zhou
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Hongyang Sun
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xiaoxiao Wang
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - He Zhu
- The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China
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12
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García-Vega A, Sanz-Ronda FJ, Fernandes Celestino L, Makrakis S, Leunda PM. Potamodromous brown trout movements in the North of the Iberian Peninsula: Modelling past, present and future based on continuous fishway monitoring. Sci Total Environ 2018; 640-641:1521-1536. [PMID: 30021318 DOI: 10.1016/j.scitotenv.2018.05.339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/25/2018] [Accepted: 05/27/2018] [Indexed: 05/25/2023]
Abstract
Brown trout uses river flow and thermal regimens as main stimuli for initiating and maintaining behavioral reactions such as migration and spawning. Therefore, anthropogenic alterations on these factors may have strong impacts on its populations. The aim of this work is to understand these consequences by assessing potamodromous brown trout movements in the past and present, and to model future responses. For this, brown trout movements in a fishway in the Marin River (Bidasoa basin, Northern Iberian Peninsula) have been monitored from 2008 to 2017. Random forest regression has been used to assess the influence of environmental variables on brown trout movements and to model the response under hypothetical climatic and hydrological scenarios. Results show that brown trout uses the fishway during the whole year, with more upstream movements during the spawning season. The model is able to predict accurately the timing and number of migrants. Its use under hypothetical climate change and flow regulation scenarios shows a delay in the migration time. Therefore, modelling using large time series can be a powerful tool to define management and conservation strategies and prepare compensation measures for future scenarios.
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Affiliation(s)
- Ana García-Vega
- Department of Hydraulics and Hydrology, University of Valladolid, Avenida de Madrid 44, Campus La Yutera, 34004 Palencia, Spain.
| | - Francisco Javier Sanz-Ronda
- Department of Hydraulics and Hydrology, University of Valladolid, Avenida de Madrid 44, Campus La Yutera, 34004 Palencia, Spain.
| | - Leandro Fernandes Celestino
- Grupo de Pesquisa em Tecnologia em Ecohidráulica e Conservação de Recursos Pesqueiros e Hídricos - GETECH, Universidade Estadual do Oeste do Paraná, Jardim Santa Maria, Toledo, Brazil.
| | - Sergio Makrakis
- Grupo de Pesquisa em Tecnologia em Ecohidráulica e Conservação de Recursos Pesqueiros e Hídricos - GETECH, Universidade Estadual do Oeste do Paraná, Jardim Santa Maria, Toledo, Brazil.
| | - Pedro M Leunda
- Gestión Ambiental de Navarra, S.A. Calle Padre Adoain, 219 bajo, 31015 Pamplona/Iruña, Spain.
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13
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Tang Q, Collins AL, Wen A, He X, Bao Y, Yan D, Long Y, Zhang Y. Particle size differentiation explains flow regulation controls on sediment sorting in the water-level fluctuation zone of the Three Gorges Reservoir, China. Sci Total Environ 2018; 633:1114-1125. [PMID: 29758863 DOI: 10.1016/j.scitotenv.2018.03.258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/20/2018] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
The Three Gorges Dam has significantly interrupted fluvial continuity and modified the mass transfer regime along river continuums. Flow regulation following regular dam operations drives dramatic hydrological regime shifts, which facilitates sediment dispersal in the water-level fluctuation zone over episodic inundation periods. How flow regulation modulates sediment redistribution, however, remains unclear. In this study, we depict absolute particle size composition of suspended sediment and sink sediment in the water-level fluctuation zone, and these are interpreted in the context of flow regulation controls on sediment sorting. Multiple sampling strategies were applied at different spatial and temporal scales, to overcome limitations of labour and cost input in a large-scale field study and to collect representative samples. The results revealed a longitudinal fining trend and seasonal variability in particle size composition for suspended sediment. Sink sediment collected from the water-level fluctuation zone during a single summer flood event displayed a similar longitudinal fining trend, reflecting preferential settling of coarser fractions in the backwater reaches where flow velocity declines sharply. Surface sediment demonstrated a laterally coarsening trend with increasing elevations along a slope profile. Flooding duration, frequency and timing represent key factors in determining the elevation-dependent variations in the magnitude of sedimentation and its source inputs. Relatively longer flooding duration and frequent intermediate summer floods with high suspended sediment flux are responsible for high sedimentation rates in the lower portions with distal upstream source inputs, while low sedimentation rates in the upper portions are principally associated with water impoundment and sediment produced from local bank erosion. Vertical particle size variability was observed along a sedimentary core profile, which most likely reflects seasonal differences in source supply with contrasting particle size characteristics. We conclude that absolute particle size differentiation explains flow regulation controls on sediment sorting in the water-level fluctuation zone of the Three Gorges Reservoir.
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Affiliation(s)
- Qiang Tang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK
| | - Adrian L Collins
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK
| | - Anbang Wen
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xiubin He
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Yuhai Bao
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Dongchun Yan
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
| | - Yi Long
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Yusheng Zhang
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK
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14
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Vietz GJ, Lintern A, Webb JA, Straccione D. River Bank Erosion and the Influence of Environmental Flow Management. Environ Manage 2018; 61:454-468. [PMID: 28386746 DOI: 10.1007/s00267-017-0857-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 03/27/2017] [Indexed: 06/07/2023]
Abstract
Environmental flows aim to influence river hydrology to provide appropriate physical conditions for ecological functioning within the restrictions of flow regulation. The hydrologic characteristics of flow events, however, may also lead to unintended morphologic effects in rivers, such as increases in riverbank erosion beyond natural rates. This may negatively impact habitat for biota, riparian infrastructure, and land use. Strategic environmental flow delivery linked to monitoring and adaptive management can help mitigate risks. We monitor riverbank condition (erosion and deposition) relative to environmental flows on the Goulburn River, Victoria, Australia. We describe the process of adaptive management aimed at reducing potential impacts of flow management on bank condition. Field measurements (erosion pins) quantify the hydrogeomorphic response of banks to the delivery of planned and natural flow events. Managed flows provide opportunities for monitoring riverbank response to flows, which in turn informs planning. The results demonstrate that environmental flows have little influence on bank erosion and visual perceptions in the absence of monitoring are an unreliable guide. This monitoring project represents a mutually beneficial, science-practice partnership demonstrating that a traditional 'know then do' approach can be foreshortened by close collaboration between researchers and managers. To do so requires transparent, often informal lines of communication. The benefits for researchers-a more strategic and targeted approach to monitoring activities; and benefits for the practitioners-reduced time between actions and understanding response; mean that a learn by doing approach is likely to have better outcomes for researchers, stakeholders, the public, and the environment.
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Affiliation(s)
- Geoff J Vietz
- Streamology Pty Ltd, 20 Iarias Lane, Bright, VIC 3741, Australia.
| | - Anna Lintern
- Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
| | - J Angus Webb
- Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
| | - David Straccione
- Commonwealth Environmental Water Office, GPO Box 787 Canberra, Canberra, ACT 2601, Australia
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15
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Wolfenden BJ, Wassens SM, Jenkins KM, Baldwin DS, Kobayashi T, Maguire J. Adaptive Management of Return Flows: Lessons from a Case Study in Environmental Water Delivery to a Floodplain River. Environ Manage 2018; 61:481-496. [PMID: 28474208 DOI: 10.1007/s00267-017-0861-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
For many floodplain rivers, reinstating wetland connectivity is necessary for ecosystems to recover from decades of regulation. Environmental return flows (the managed delivery of wetland water to an adjacent river) can be used strategically to facilitate natural ecosystem connectivity, enabling the transfer of nutrients, energy, and biota from wetland habitats to the river. Using an informal adaptive management framework, we delivered return flows from a forested wetland complex into a large lowland river in south-eastern Australia. We hypothesized that return flows would (a) increase river nutrient concentrations; (b) reduce wetland nutrient concentrations; (c) increase rates of ecosystem metabolism through the addition of potentially limiting nutrients, causing related increases in the concentration of water column chlorophyll-a; and (d) increase the density and species richness of microinvertebrates in riverine benthic habitats. Our monitoring results demonstrated a small increase in the concentrations of several key nutrients but no evidence for significant ecological responses was found. Although return flows can be delivered from forested floodplain areas without risking hypoxic blackwater events, returning nutrient and carbon-rich water to increase riverine productivity is limited by the achievable scale of return flows. Nevertheless, using return flows to flush carbon from floodplains may be a useful management tool to reduce carbon loads, preparing floodplains for subsequent releases (e.g., mitigating the risk of hypoxic blackwater events). In this example, adaptive management benefited from a semi-formal collaboration between science and management that allowed for prompt decision-making.
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Affiliation(s)
- Benjamin J Wolfenden
- Institute of Land Water and Society, Charles Sturt University, PO Box 789, Albury, 2640, Australia.
| | - Skye M Wassens
- Institute of Land Water and Society, Charles Sturt University, PO Box 789, Albury, 2640, Australia
| | - Kim M Jenkins
- Institute of Land Water and Society, Charles Sturt University, PO Box 789, Albury, 2640, Australia
| | - Darren S Baldwin
- Institute of Land Water and Society, Charles Sturt University, PO Box 789, Albury, 2640, Australia
- CSIRO Land and Water and the Murray-Darling Freshwater Research Centre, La Trobe University, Wodonga, VIC, 3689, Australia
| | - Tsuyoshi Kobayashi
- Institute of Land Water and Society, Charles Sturt University, PO Box 789, Albury, 2640, Australia
- Science Division, Office of Environment and Heritage NSW, PO Box A290, Sydney South, NSW, 1232, Australia
| | - James Maguire
- Regional Operations Group (South Branch), Office of Environment and Heritage NSW, PO Box 544, Albury, NSW, 2640, Australia
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16
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Motohashi Y, Shimada R, Sasaki T, Katsumata T, Dan K, Tsutsui Y, Nemoto S. Development of a simple device enabling percutaneous flow regulation for a small vascular graft for a Blalock–Taussig shunt capable of flow regulation: complete translation of an original article originally published in Pediatric Cardiology and Cardiac Surgery (154–159, 2016: vol. 32). Gen Thorac Cardiovasc Surg 2018; 66:145-9. [PMID: 29124558 DOI: 10.1007/s11748-017-0860-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 11/01/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVES The Blalock-Taussig shunt (BTS) operation is a cornerstone as initial palliative surgery for congenital heart disease with severely reduced pulmonary blood flow (PBF). The ideal PBF provided by BTS is crucial for an uneventful postoperative course, since excess PBF results in acute distress of the systemic circulation and insufficient PBF requires another BTS surgery. Therefore, the goal of this study was to develop a simple device to control the shunt graft flow percutaneously using a constrictor balloon connected to a subcutaneous port. METHODS The device consists of a cylindrical balloon and an anti-bending structure extension connected to the balloon center. A PTFE vascular graft wrapped by the device was connected to a simulated closed circuit to measure the relationship between pressure and blood flow while changing the inner volume of the balloon. In a beagle model of replacement of the right carotid artery, blood flow velocity was measured in the carotid artery after saline injection into the balloon. The blood flow velocity before and after balloon inflation was compared immediately after implantation of the device and at 3 months after implantation. RESULTS The device provided good flow control by inflating and deflating the balloon ex vivo and in vivo for up to 3 months in a canine model with a small graft wrapped with the device. CONCLUSIONS The simple device developed in this study may enable regulation of PBF through a small vascular graft and help to prevent severe morbidity and mortality in the clinical setting of BTS.
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17
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Alonso C, Román A, Bejarano MD, Garcia de Jalon D, Carolli M. A graphical approach to characterize sub-daily flow regimes and evaluate its alterations due to hydropeaking. Sci Total Environ 2017; 574:532-543. [PMID: 27648531 DOI: 10.1016/j.scitotenv.2016.09.087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/19/2016] [Accepted: 09/11/2016] [Indexed: 06/06/2023]
Abstract
Most flow regime characterizations focus on long time scale flow patterns, which are not precise enough to capture key components of short-term flow fluctuations. Recent proposed methods describing sub-daily flow fluctuations are focused on limited components of the flow regime being unable to fully represent it, or on the identification of peaking events based on subjectively defined thresholds, being unsuitable for evaluations of short-term flow regime alterations through comparisons between regulated and free-flowing rivers. This study aims to launch an innovative approach based on the visual display of quantitative information to address the challenge of the short-term hydrologic characterization and evaluation of alteration resulting from hydropeaking. We propose a graphical method to represent a discrete set of ecologically relevant indices that characterize and evaluate the alteration of sub-daily flow regimes. The frequency of occurrence of classified values of a descriptive hydrological variable is represented in a map-like graph where longitude, latitude and altitude represent the Julian day, the value of the variable and the frequency of occurrence, respectively. Subsequently, we tested the method on several rivers, both free-flowing and subjected to hydropower production. The advantages of our approach compared to other analytical methods are: (i) it displays a great amount of information without oversimplification; (ii) it takes into account changes in the intensity, timing and frequency of the sub-daily flows, without needing a priori defined thresholds to identify hydropeaking events; and (iii) it supports the Water Framework Directive goal. Specifically, results from applications of our graphical method agree with Sauterleute and Charmasson (2014) analytical method.
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Affiliation(s)
- Carlos Alonso
- Department of Natural Systems and Resources, Technical University of Madrid (UPM), Ciudad Universitaria, SN, 28040 Madrid, Spain.
| | - Alfonso Román
- Department of Natural Systems and Resources, Technical University of Madrid (UPM), Ciudad Universitaria, SN, 28040 Madrid, Spain.
| | - Maria Dolores Bejarano
- Landscape Ecology Group, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden.
| | - Diego Garcia de Jalon
- Department of Natural Systems and Resources, Technical University of Madrid (UPM), Ciudad Universitaria, SN, 28040 Madrid, Spain.
| | - Mauro Carolli
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, Trento, Italy.
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18
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Tang Q, Bao Y, He X, Fu B, Collins AL, Zhang X. Flow regulation manipulates contemporary seasonal sedimentary dynamics in the reservoir fluctuation zone of the Three Gorges Reservoir, China. Sci Total Environ 2016; 548-549:410-420. [PMID: 26803740 DOI: 10.1016/j.scitotenv.2015.12.158] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 06/05/2023]
Abstract
Since the launch of the Three Gorges Dam on the Yangtze River, a distinctive reservoir fluctuation zone has been created and significantly modified by regular dam operations. Sediment redistribution within this artificial landscape differs substantially from that in natural fluvial riparian zones, due to a specific hydrological regime comprising steps of water impoundment with increasing magnitudes and seasonal water level fluctuation holding a range of sediment fluxes. This study reinterpreted post-dam sedimentary dynamics in the reservoir fluctuation zone by stratigraphy determination of a 345-cm long sediment core, and related it to impact of the hydrological regime. Seasonality in absolute grain-size composition of suspended sediment was applied as a methodological basis for stratigraphic differentiation. Sedimentary laminations with relatively higher proportions of sandy fractions were ascribed to sedimentation during the dry season when proximal subsurface bank erosion dominates source contributions, while stratigraphy with a lower proportion of sandy fractions is possibly contributed by sedimentation during the wet season when distal upstream surface erosion prevails. Chronology determination revealed non-linear and high annual sedimentation rates ranging from 21.7 to 152.1cm/yr. Although channel geomorphology may primarily determine the spatial extent of sedimentation, seasonal sedimentary dynamics was predominantly governed by the frequency, magnitude, and duration of flooding. Summer inundation by natural floods with enhanced sediment loads produced from upstream basins induced higher sedimentation rates than water impoundment during the dry season when distal sediment supply was limited. We thus conclude that flow regulation manipulates contemporary seasonal sedimentary dynamics in the reservoir fluctuation zone, though little impact on total sediment retention rate was detected. Ongoing reductions in flow and sediment supply under human disturbance may have profound implications in affecting sedimentary equilibrium in the reservoir fluctuation zone. The results herein provide insights of how big dams have disrupted the sediment conveyance processes of large scale fluvial systems.
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Affiliation(s)
- Qiang Tang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuhai Bao
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xiubin He
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
| | - Bojie Fu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Adrian L Collins
- Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
| | - Xinbao Zhang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
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19
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von Schiller D, Aristi I, Ponsatí L, Arroita M, Acuña V, Elosegi A, Sabater S. Regulation causes nitrogen cycling discontinuities in Mediterranean rivers. Sci Total Environ 2016; 540:168-177. [PMID: 26233271 DOI: 10.1016/j.scitotenv.2015.07.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/04/2015] [Accepted: 07/04/2015] [Indexed: 06/04/2023]
Abstract
River regulation has fundamentally altered large sections of the world's river networks. The effects of dams on the structural properties of downstream reaches are well documented, but less is known about their effect on river ecosystem processes. We investigated the effect of dams on river nutrient cycling by comparing net uptake of total dissolved nitrogen (TDN), phosphorus (TDP) and organic carbon (DOC) in river reaches located upstream and downstream from three reservoir systems in the Ebro River basin (NE Iberian Peninsula). Increased hydromorphological stability, organic matter standing stocks and ecosystem metabolism below dams enhanced the whole-reach net uptake of TDN, but not that of TDP or DOC. Upstream from dams, river reaches tended to be at biogeochemical equilibrium (uptake≈release) for all nutrients, whereas river reaches below dams acted as net sinks of TDN. Overall, our results suggest that flow regulation by dams may cause relevant N cycling discontinuities in rivers. Higher net N uptake capacity below dams could lead to reduced N export to downstream ecosystems. Incorporating these discontinuities could significantly improve predictive models of N cycling and transport in complex river networks.
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Affiliation(s)
- Daniel von Schiller
- Catalan Institut e for Water Research, Carrer d'Emili Grahit, 101, 17003 Girona, Spain.
| | - Ibon Aristi
- Faculty of Science and Technology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain.
| | - Lídia Ponsatí
- Catalan Institut e for Water Research, Carrer d'Emili Grahit, 101, 17003 Girona, Spain.
| | - Maite Arroita
- Faculty of Science and Technology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain.
| | - Vicenç Acuña
- Catalan Institut e for Water Research, Carrer d'Emili Grahit, 101, 17003 Girona, Spain.
| | - Arturo Elosegi
- Faculty of Science and Technology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain.
| | - Sergi Sabater
- Catalan Institut e for Water Research, Carrer d'Emili Grahit, 101, 17003 Girona, Spain; Institute of Aquatic Ecology, University of Girona, Campus de Montilivi 17071, Girona, Spain.
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20
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Abril M, Muñoz I, Casas-Ruiz JP, Gómez-Gener L, Barceló M, Oliva F, Menéndez M. Effects of water flow regulation on ecosystem functioning in a Mediterranean river network assessed by wood decomposition. Sci Total Environ 2015; 517:57-65. [PMID: 25721144 DOI: 10.1016/j.scitotenv.2015.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 05/25/2023]
Abstract
Mediterranean rivers are extensively modified by flow regulation practises along their courses. An important part of the river impoundment in this area is related to the presence of small dams constructed mainly for water abstraction purposes. These projects drastically modified the ecosystem morphology, transforming lotic into lentic reaches and increasing their alternation along the river. Hydro-morphologial differences between these reaches indicate that flow regulation can trigger important changes in the ecosystem functioning. Decomposition of organic matter is an integrative process and this complexity makes it a good indicator of changes in the ecosystem. The aim of this study was to assess the effect caused by flow regulation on ecosystem functioning at the river network scale, using wood decomposition as a functional indicator. We studied the mass loss from wood sticks during three months in different lotic and lentic reaches located along a Mediterranean river basin, in both winter and summer. Additionally, we identified the environmental factors affecting decomposition rates along the river orders. The results revealed differences in decomposition rates between sites in both seasons that were principally related to the differences between stream orders. The rates were mainly related to temperature, nutrient concentrations (NO2(-), NO3(2-)) and water residence time. High-order streams with higher temperature and nutrient concentrations exhibited higher decomposition rates compared with low-order streams. The effect of the flow regulation on the decomposition rates only appeared to be significant in high orders, especially in winter, when the hydrological characteristics of lotic and lentic habitats widely varied. Lotic reaches with lower water residence time exhibited greater decomposition rates compared with lentic reaches probably due to more physical abrasion and differences in the microbial assemblages. Overall, our study revealed that in high orders the reduction of flow caused by flow regulation affects the wood decomposition indicating changes in ecosystem functioning.
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Affiliation(s)
- Meritxell Abril
- Department of Ecology, Faculty of Biology, University of Barcelona, Barcelona, Spain.
| | - Isabel Muñoz
- Department of Ecology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | | | - Lluís Gómez-Gener
- Department of Ecology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Milagros Barceló
- Department of Ecology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Francesc Oliva
- Department of Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Margarita Menéndez
- Department of Ecology, Faculty of Biology, University of Barcelona, Barcelona, Spain
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Lobera G, Besné P, Vericat D, López-Tarazón JA, Tena A, Aristi I, Díez JR, Ibisate A, Larrañaga A, Elosegi A, Batalla RJ. Geomorphic status of regulated rivers in the Iberian Peninsula. Sci Total Environ 2015; 508:101-114. [PMID: 25474167 DOI: 10.1016/j.scitotenv.2014.10.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/17/2014] [Accepted: 10/17/2014] [Indexed: 06/04/2023]
Abstract
River regulation by dams modifies flow regimes, interrupts the transfer of sediment through channel networks, and alters downstream bed dynamics, altogether affecting channel form and processes. So far, most studies on the geomorphic impacts of dams are restricted to single rivers, or even single river stretches. In this paper we analyse the geomorphic status of 74 river sites distributed across four large basins in the Iberian Peninsula (i.e. 47 sites located downstream of dams). For this purpose, we combine field data with hydrological data available from water agencies, and analyse historical (1970) and current aerial photographs. In particular, we have developed a Geomorphic Status (GS) index that allows us to assess the physical structure of a given channel reach and its change through time. The GS encompasses a determination of changes in sedimentary units, sediment availability, bar stability and channel flow capacity. Sites are statistically grouped in four clusters based on contrasted physical and climate characteristics. Results emphasise that regulation changes river's flow regime with a generalized reduction of the magnitude and frequency of floods (thus flow competence). This, in addition to the decrease downstream sediment supply, results in the loss of active bars as they are encroached by vegetation, to the point that only reaches with little or no regulation maintain exposed sedimentary deposits. The GS of regulated river reaches is negatively correlated with magnitude of the impoundment (regulation). Heavily impacted reaches present channel stabilization and, in contrast to the hydrological response, the distance and number of tributaries do not reverse the geomorphic impact of the dams. Stabilization limits river dynamics and may contribute to the environmental degradation of the fluvial ecosystem. Overall, results describe the degree of geomorphological alteration experienced by representative Iberian rivers mostly because of regulation, challenging the successful long-term implementation of river basin management programmes.
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Affiliation(s)
- G Lobera
- Fluvial Dynamics Research Group - RIUS, University of Lleida, Lleida, E-25198 Catalonia, Spain.
| | - P Besné
- Department of Geography, Prehistory and Archaeology, University of the Basque Country, 01006 Vitoria-Gasteiz, Spain
| | - D Vericat
- Fluvial Dynamics Research Group - RIUS, University of Lleida, Lleida, E-25198 Catalonia, Spain; Forest Sciences Centre of Catalonia, Solsona, E-25280 Catalonia, Spain; Institute of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, Wales, UK
| | - J A López-Tarazón
- Fluvial Dynamics Research Group - RIUS, University of Lleida, Lleida, E-25198 Catalonia, Spain; School of Natural Sciences and Psychology, Liverpool John Moores University, L3 3AF Liverpool, UK
| | - A Tena
- Fluvial Dynamics Research Group - RIUS, University of Lleida, Lleida, E-25198 Catalonia, Spain
| | - I Aristi
- Faculty of Science and Technology, University of the Basque Country, 48080 Bilbao, Spain
| | - J R Díez
- Faculty of Education, University of the Basque Country, 01006 Vitoria-Gasteiz, Spain
| | - A Ibisate
- Department of Geography, Prehistory and Archaeology, University of the Basque Country, 01006 Vitoria-Gasteiz, Spain
| | - A Larrañaga
- Faculty of Science and Technology, University of the Basque Country, 48080 Bilbao, Spain
| | - A Elosegi
- Faculty of Science and Technology, University of the Basque Country, 48080 Bilbao, Spain
| | - R J Batalla
- Fluvial Dynamics Research Group - RIUS, University of Lleida, Lleida, E-25198 Catalonia, Spain; Forest Sciences Centre of Catalonia, Solsona, E-25280 Catalonia, Spain; Catalan Institute for Water Research, Girona, E-17003 Catalonia, Spain
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