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Liu Y, Mao Y, Gui J, Long Y, Wen Y, Xie S, Sun J. Stratification of dissolved organic matter in the upper 5000 m water column in the western Pacific Ocean. MARINE ENVIRONMENTAL RESEARCH 2024; 194:106346. [PMID: 38215625 DOI: 10.1016/j.marenvres.2024.106346] [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: 09/26/2023] [Revised: 12/12/2023] [Accepted: 01/07/2024] [Indexed: 01/14/2024]
Abstract
Marine dissolved organic matter (DOM) is a principal reservoir involved in biogeochemical cycles and exerts a pivotal influence on global carbon flux dynamics. In this study, excitation-emission matrix fluorescence spectroscopy combined with parallel factor analysis (EEM-PARAFAC) was conducted on 230 DOM samples collected from 21 sites between February and April 2022 in the Western Pacific Ocean (WPO). We identified five distinct fluorescence peaks (peaks B, T, A, C, and M), predominantly protein-like and humic-like components. These findings, marked by significant differences (p < 0.01) in fluorescence intensities and spectral indices, characterized the transformation of DOM with ocean depth, illustrating a transition from active to recalcitrant forms. Additionally, random forest analysis (RFA) identified depth as a key factor influencing marine dissolved organic carbon (DOC), with a 32.59% importance value. Correlations between hydrological and fluorescent parameters underscored the complexity of DOM sources and influencing processes. Overall, this work broadens our understanding of DOM variability in the upper 5000 m of the WPO, enhancing our knowledge of the marine environment's role in the global carbon cycle.
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Affiliation(s)
- Yang Liu
- School of Life Science, Shanxi University, Taiyuan, 030006, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Yingjie Mao
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, PR China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jiang Gui
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, PR China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Yi Long
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, PR China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Yujian Wen
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Shulian Xie
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, PR China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, 300457, China.
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2
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Manninen N, Kanerva S, Lemola R, Turtola E, Soinne H. Contribution of water erosion to organic carbon and total nitrogen loads in agricultural discharge from boreal mineral soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167300. [PMID: 37742969 DOI: 10.1016/j.scitotenv.2023.167300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/07/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
While organic carbon (OC) in agricultural mineral soils is widely studied in terms of soil carbon sequestration and gaseous emissions, discharge-induced OC loss from soil is still poorly understood and estimations of boreal soil OC loads within water erosion are lacking. Loss of organic matter from arable soils is a concern for surface water quality, climate change and soil productivity. The main aim of this study was to quantify the role of water erosion in total OC and nitrogen (N) loads exported in agricultural discharge from boreal mineral soils under various cultivation practices. Surface water and subsurface drainage were collected near-continually over 2 years in two clayey and one sandy soil in Finland. Eroded sediment was mechanically separated by centrifugation from all discharge samples to detect sediment OC% and N% by dry-combustion method. Dissolved OC and N concentrations in selected discharge samples were measured with high-temperature catalytic oxidation of unfiltered supernatant. A multiple linear regression model was used to study the significant factors affecting dissolved, sediment and total OC loads. In the clayey soils, the sediment OC (2-24 kg ha-1 y-1) and N (0.2-1.1 kg ha-1 y-1) export accounted for up to 35 % and 20 % of the annual discharge-induced total loads of OC (19-85 kg ha-1) and N (2-8 kg ha-1), respectively. In the sandy soil, erosion was negligible and dissolved loads of 17-35 kg OC ha-1 y-1and 4-7 kg N ha-1 y-1 were detected. Subsurface drainage exported most of the sediment-associated OC and N loads from clayey soils. For the total OC loads, the distribution varied between the discharge routes, while the total N loads were mostly exported in subsurface drainage in both soil types. Sediment OC and N exports were related to soil plowing and discharge intensity, while dissolved OC loss was promoted by high surface soil OC%. Our results also indicated that a single cultivation practice may affect sediment and dissolved loads in opposite ways. These findings can be used to complement carbon budget estimations for mineral agricultural soils, and to assess soil management effects on terrestrial organic matter loading to boreal surface waters.
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Affiliation(s)
- Noora Manninen
- University of Helsinki, Department of Agricultural Sciences, Unit of Environmental Soil Science, Viikinkaari 9, P.O. Box 56, FI-00014 Helsinki, Finland.
| | - Sanna Kanerva
- University of Helsinki, Department of Agricultural Sciences, Unit of Environmental Soil Science, Viikinkaari 9, P.O. Box 56, FI-00014 Helsinki, Finland
| | - Riitta Lemola
- Natural Resources Institute Finland, Tietotie 4, FI-31600 Jokioinen, Finland
| | - Eila Turtola
- Natural Resources Institute Finland, Tietotie 4, FI-31600 Jokioinen, Finland
| | - Helena Soinne
- Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790 Helsinki, Finland
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3
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Liu Y, Xue J, Gui Z, Zhang L, Yao X. Short-term photodegradation of autochthonous and allochthonous dissolved organic matter in Lake Taihu, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:111982-111994. [PMID: 37821739 DOI: 10.1007/s11356-023-30107-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 09/24/2023] [Indexed: 10/13/2023]
Abstract
Photochemistry is one of the key processes that shape the quality of dissolved organic matter (DOM) in aquatic systems, yet the photoreactivity of DOM from different sources remains largely unclear. In this study, DOM from 10 typical autochthonous and allochthonous sources in Lake Taihu basin were exposed to simulated sunlight, and quantitative and compositional changes of the DOM were explored by measuring its UV-Visable absorption and fluorescence spectroscopy. Photochemical release of nutrients was also explored during the incubations. Results showed that, although DOM from most sources experienced photobleaching effects with decreased absorption coefficients at 254 nm (a(254)) and fluorescence component intensities after light exposure, photochemical alterations of DOM linked to their original composition. Macrophyte-derived (Potamogeton malaianus) DOM, with the largest molecular size, showed increased a(254), humic- and protein-like fluorescence component (C1 and C2) abundances, and inorganic nutrient concentrations relative to dark controls, indicating photo-release of labile components. However, DOM with relatively higher aromaticity, e.g., from agricultural water and the lake, showed photobleaching effects and increased humification degree, probably due to the loss of aromatic components. Allochthonous anthropogenic DOM, e.g., from sewage, showed stronger photo-ammonification, likely relating to the fresh labile N-containing compositions. The form of inorganic nutrient releases during the DOM photolysis also varied with the original DOM sources. Macrophyte-derived DOM incubations showed larger photo-releases of NO3- and PO43-, while NO2- dominated inorganic nutrient releases during groundwater DOM light incubations. Thus, this study concludes that the photoreactivity of DOM closely relates to its original composition and sources.
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Affiliation(s)
- Yanan Liu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
- College of Urban and Environmental Sciences, Hubei Normal University, Huangshi, 435002, China
| | - Jingya Xue
- School of Geography Science, Nanjing Normal University, Nanjing, 210023, China
| | - Zhifan Gui
- College of Urban and Environmental Sciences, Hubei Normal University, Huangshi, 435002, China
| | - Lu Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xiaolong Yao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
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Lloyd CEM, Johnes PJ, Pemberton JA, Yates CA, Jones D, Evershed RP. Sampling, storage and laboratory approaches for dissolved organic matter characterisation in freshwaters: Moving from nutrient fraction to molecular-scale characterisation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154105. [PMID: 35219656 DOI: 10.1016/j.scitotenv.2022.154105] [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: 12/23/2021] [Revised: 02/18/2022] [Accepted: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Recent research has highlighted the importance of dissolved organic matter (DOM) for ecosystem function and because of this paradigm shift, it has become crucial to not only quantify its contribution to river nutrient loads but also to characterise its composition. There has been a significant research effort utilising optical methods, such as fluorescence and UV-Vis spectrophotometry, in order to start exploring DOM character. However, these methods still lack the granularity to understand the chemical composition at the molecular level, which is vital to properly understanding its functional role in freshwater ecosystems. As a direct result, there has been a shift towards including molecular-scale analyses to investigate the in-stream processing of the material. Alongside this, recent methodological advancements, particularly in mass spectrometry are opening new opportunities for probing one of the most complex environmental mixtures. However, in order to fully exploit these opportunities, it is key that the way that samples are collected, processed and stored is considered carefully such that sample integrity is maintained. There are additional challenges when collecting water samples for analysis at molecular scale, for example the ultra-low concentrations of individual compounds within DOM means that the samples are sensitive to contamination. This paper discusses current sample collection, processing and storage protocols for this C, N and P quantification and characterisation in freshwaters, and proposes a new standardised protocol suitable for both nutrient fraction quantification and molecular scale analyses, based on method development and testing undertaken in our UK Natural Environment Research Council large grant programme, characterising the nature, origins and ecological significance of Dissolved Organic Matter IN freshwater Ecosystems (DOMAINE).
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Affiliation(s)
- C E M Lloyd
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK.
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK
| | - J A Pemberton
- Wessex Water, Operations Centre, Claverton Down, Bath BA2 7WW, UK
| | - C A Yates
- School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK; Atkins, The Hub, 500 Park Avenue, Aztec West, Bristol BS32 4RZ, UK
| | - D Jones
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; SoilsWest, Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA 6105, Australia
| | - R P Evershed
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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5
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Li X, Yang J, Fan Y, Xie M, Qian X, Li H. Rapid monitoring of heavy metal pollution in lake water using nitrogen and phosphorus nutrients and physicochemical indicators by support vector machine. CHEMOSPHERE 2021; 280:130599. [PMID: 33940448 DOI: 10.1016/j.chemosphere.2021.130599] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/26/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
A novel method of predicting heavy metal concentration in lake water by support vector machine (SVM) model was developed, combined with low-cost, easy to obtain nutrients and physicochemical indicators as input variables. 115 surface water samples were collected from 23 sites in Chaohu Lake, China, during different hydrological periods. The particulate concentrations of heavy metals in water were much higher than the dissolved concentrations. According to Nemerow pollution index (Pi), pollution degrees by Fe, V, Mn and As ranged from heavy (2 ≤ Pi < 4) to serious (Pi ≥ 4). The concentrations of most heavy metals were the highest during the medium-water period and the lowest during the dry season. Non-metric Multidimensional Scaling Analysis confirmed heavy metal concentrations had slight spatial difference but relatively large seasonal variation. Redundancy Analysis indicated the close associations of heavy metals with nutrient and physicochemical indicators. When both nutrient and physicochemical indicators were used as input variables, the simulation effects for most elements in total and particulate were relatively better than those obtained using only nutrient or only physicochemical indicators. The simulation effects for As, Ba, Fe, Ti, V and Zn were generally good, based on their training R values of 0.847, 0.828, 0.856, 0.867, 0.817 and 0.893, respectively, as well as their test R values of 0.811, 0.836, 0.843, 0.873, 0.829 and 0.826, respectively; and meanwhile, in both the training and test stages, these metals also had relatively lower errors. The spatial distribution of heavy metals in Chaohu Lake was then predicted using the fully trained SVM models.
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Affiliation(s)
- Xiaolong Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; School of Earth and Environment, Anhui University of Science and Technology, Huainan, 232001, PR China
| | - Jinxiang Yang
- School of Earth and Environment, Anhui University of Science and Technology, Huainan, 232001, PR China
| | - Yifan Fan
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Mengxing Xie
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Xin Qian
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
| | - Huiming Li
- School of Environment, Nanjing Normal University, Nanjing, 210023, PR China.
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Li X, Yang B, Yang J, Fan Y, Qian X, Li H. Magnetic properties and its application in the prediction of potentially toxic elements in aquatic products by machine learning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 783:147083. [PMID: 34088131 DOI: 10.1016/j.scitotenv.2021.147083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/04/2021] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
Magnetic measurement was provided to substitute for time-consuming conventional methods for determination of potentially toxic elements. Both the concentrations of 12 elements and 9 magnetic parameters were determined in 700 muscle tissue samples from the snail Bellamya aeruginosa, shrimp species Exopalaemon modestus and Macrobrachium nipponense, and fish species Hemisalanx prognathous Regan, Coilia ectenes taihuensis, and Culer alburnus Basilewsky collected from Chaohu Lake during different hydrological periods. Spherical and irregular iron oxide particles were observed in the muscle tissues of the studied aquatic products. A field survey of the exposure parameters in humans, such as per capita intake dose of local aquatic products, found no evidence that consumption of the tested species poses a potential health risk. Redundancy analysis revealed different degrees of correlation between the magnetic parameters and concentrations of elements in aquatic products. Back-propagation artificial neural network (BP-ANN) and support vector machine (SVM) models were applied to predict elemental concentrations in aquatic products, using magnetic parameters as input. SVM models performed well in predicting the presence of Cr and Ni, with R and index of agreement values of >0.8 in both training and validation stages as well as relatively low errors. The BP-ANN and SVM models both performed relatively poorly in predicting the presence of Cd and Zn in aquatic products, with R values between 0.333 and 0.718 for Cd and between 0.454 and 0.664 for Zn in training and validation stages. For most of the elements, a better R value was obtained with the SVM than with BP-ANN model. The R of Co, Cr, Cu, Ni, and Ti in the training and validation stages of snail in the SVM model were >0.8. This study is a first step in developing a novel approach allowing the rapid monitoring of potentially toxic elements concentrations in aquatic products.
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Affiliation(s)
- Xiaolong Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, PR China
| | - Biying Yang
- School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, PR China
| | - Jinxiang Yang
- School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, PR China
| | - Yifan Fan
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Xin Qian
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Huiming Li
- School of Environment, Nanjing Normal University, Nanjing 210023, PR China.
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Liu J, Liang J, Bravo AG, Wei S, Yang C, Wang D, Jiang T. Anaerobic and aerobic biodegradation of soil-extracted dissolved organic matter from the water-level-fluctuation zone of the Three Gorges Reservoir region, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142857. [PMID: 33160674 DOI: 10.1016/j.scitotenv.2020.142857] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/27/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
The biodegradation of dissolved organic matter (DOM) in natural environments is determined by its molecular composition and reactivity. Redox oscillations are common in the water-level-fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR). As a consequence, the soil DOM released is degraded under both anaerobic and aerobic conditions. The DOM compounds available for degradation under contrasting redox conditions and the resulting DOM composition still need to be elucidated. By combining laboratory experiments with an in-depth characterization of DOM optical properties, we show that different pathways controlled the depletion and enrichment of the DOM optical components under different oxygen regimes. In particular, 28-day dark biodegradation assays showed that up to 39.5 ± 4% DOM was degraded under anaerobic conditions, while 55.5 ± 6% DOM was biodegraded under aerobic conditions. Aerobic biodegradation resulted in a higher aromaticity and degree of humification of the DOM compared to anaerobic degradation. The specific UV absorbance at a wavelength of 254 (SUVA254) and biological index (BIX) could be used to track DOM biodegradation under anaerobic conditions. Under aerobic conditions, the SUVA254, BIX and concentration of coloured DOM (CDOM, reflected by a (355)) could track DOM biodegradation, and significant amounts of CDOM could be aerobically biodegraded.
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Affiliation(s)
- Jiang Liu
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
| | - Jian Liang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; College of Chemistry and Environmental Engineering, Baise University, Guangxi 533000, China
| | - Andrea G Bravo
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Shiqiang Wei
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Caiyun Yang
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå SE-90183, Sweden.
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8
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Panton A, Couceiro F, Fones GR, Purdie DA. The impact of rainfall events, catchment characteristics and estuarine processes on the export of dissolved organic matter from two lowland rivers and their shared estuary. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 735:139481. [PMID: 32473434 DOI: 10.1016/j.scitotenv.2020.139481] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/02/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
Terrestrially-derived dissolved organic carbon (DOC) and nitrogen (DON) transported by rivers have been recognised as contributors to aquatic nutrient burdens, and can be of importance in rivers and estuaries already impacted by anthropogenic inorganic nutrient discharges. The concentration of DOC and DON and the flux of both to the estuary and ultimately the coastal zone is dependent upon many factors including rainfall, catchment land use, and biological processes. DOC and DON concentrations together with nitrate plus nitrite and ammonium concentrations were measured in the anthropogenically-impacted estuary Christchurch Harbour (UK) and at sites in the lower reaches of its two source rivers, the Hampshire Avon and the Stour, at weekly intervals for a year during which time several extreme rainfall events occurred. A series of transects along the estuary were also performed after weekly sampling was completed. DOC concentrations were correlated between both rivers and the estuary and were positively related to increases in river flow, but DON concentrations revealed a more complicated picture. Peak instantaneous fluxes of DOC and DON exceeded 60,000 kg C d-1 and 7000 kg N d-1 respectively both in the Stour and the estuary during high flow periods. The sources of both and routes by which they enter the aquatic system may account for the differences in dynamics, with flushing of superficial soils being a key source of DOC and point sources such as sewage treatment works being proposed as sources of DON. Removal processes within the estuary were also of importance for DON concentrations whilst DOC behaved more conservatively with some evidence of local production within the estuary. Estimated annual loads of DON and DOC to the coastal zone from Christchurch Harbour were 118 kg N km-2 y-1 and 2296 kg C km-2 y-1.
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Affiliation(s)
- Anouska Panton
- School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH, UK.
| | - Fay Couceiro
- School of Civil Engineering, University of Portsmouth, Burnaby Road, Portsmouth PO1 3QL, UK
| | - Gary R Fones
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth PO1 3QL, UK
| | - Duncan A Purdie
- School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
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Short-Term Effects of Fertilization on Dissolved Organic Matter in Soil Leachate. WATER 2020. [DOI: 10.3390/w12061617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Besides the importance of dissolved organic matter (DOM) in soil biogeochemical processes, there is still a debate on how agricultural intensification affects the leaching of terrestrial DOM into adjacent aquatic ecosystems. In order to close this linkage, we conducted a short-term (45 day) lysimeter experiment with silt loam and sandy loam undisturbed/intact soil cores. Mineral (calcium ammonium nitrate) or organic (pig slurry) fertilizer was applied on the soil surface with a concentration equivalent to 130 kg N ha−1. On average, amounts of leached DOC over 45 days ranged between 20.4 mg (silt loam, mineral fertilizer) and 34.4 mg (sandy loam, organic fertilizer). Both, mineral and organic fertilization of a silt loam reduced concentration of dissolved organic carbon (DOC) in the leachate and shifted its composition towards a microbial-like signature (BIX) with a higher aromaticity (Fi) and a lower molecular size (E2:E3). However, in sandy loam only mineral fertilization affected organic matter leaching. There, lowered DOC concentrations with a smaller molecular size (E2:E3) could be detected. The overall effect of fertilization on DOC leaching and DOM composition was interrelated with soil texture and limited to first 12 days. Our results highlight the need for management measures, which prevent or reduce fast flow paths leading soil water directly into aquatic systems, such as surface flow, fast subsurface flow, or drainage water.
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Carstensen J, Conley DJ, Almroth-Rosell E, Asmala E, Bonsdorff E, Fleming-Lehtinen V, Gustafsson BG, Gustafsson C, Heiskanen AS, Janas U, Norkko A, Slomp C, Villnäs A, Voss M, Zilius M. Factors regulating the coastal nutrient filter in the Baltic Sea. AMBIO 2020; 49:1194-1210. [PMID: 31707582 PMCID: PMC7128010 DOI: 10.1007/s13280-019-01282-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 05/30/2023]
Abstract
The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
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Affiliation(s)
- Jacob Carstensen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Daniel J. Conley
- Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | | | - Eero Asmala
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Erik Bonsdorff
- Environmental and Marine Biology, Åbo Akademi University, BioCity, 20500 Turku, Finland
| | | | - Bo G. Gustafsson
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
- Stockholm University Baltic Sea Centre, 106 91 Stockholm, Sweden
| | - Camilla Gustafsson
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | | | - Urzsula Janas
- Department of Experimental Ecology of Marine Organisms, Institute of Oceanography, University of Gdańsk, al. Marsz. J. Pilsudskiego 46, 81-378 Gdynia, Poland
| | - Alf Norkko
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Caroline Slomp
- Department of Earth Sciences, Utrecht University, Princetonlaan 8A, 3584 CB Utrecht, The Netherlands
| | - Anna Villnäs
- Tvärminne Zoological Station, University of Helsinki, J.A. Palmenin tie 260, 10900 Hanko, Finland
| | - Maren Voss
- Department of Biological Oceanography, Leibniz Institute of Baltic Sea Research, Seestr. 15, 18119 Rostock, Germany
| | - Mindaugas Zilius
- Marine Research Institute, Universiteto al. 17, 92294 Klaipeda, Lithuania
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11
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Münzner K, Berggren M. In situ plankton community respiration measurements show low respiratory quotients in a eutrophic lake. Environ Microbiol 2019; 21:1425-1435. [DOI: 10.1111/1462-2920.14574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/26/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Karla Münzner
- Department of Physical Geography and Ecosystem ScienceLund University Lund Sweden
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Using Soil Survey Database to Assess Soil Quality in the Heterogeneous Taihang Mountains, North China. SUSTAINABILITY 2018. [DOI: 10.3390/su10103443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Soil quality evaluation is an effective pathway to understanding the status of soil function and ecosystem productivity. Numerous studies have been made in managed ecosystems and land cover to quantify its effects on soil quality. However, little is coincident regarding soil quality assessment methods and its compatibility in highly heterogeneous soil. This paper used the soil survey database of Taihang Mountains as a case study to: (i) Examine the feasibility of soil quality evaluation with two different indicator methods: Total data set (TDS) and minimum data set (MDS); and (ii) analyze the controlling factors of regional soil quality. Principal component analysis (PCA) and the entropy method were used to calculate soil quality index (SQI). SQI values assessed from the TDS and MDS methods were both significantly correlated with normalized difference vegetation index (p < 0.001), suggesting that both indices were effective to describe soil quality and reflect vegetation growth status. However, the TDS method represented a slightly more accurate assessment than MDS in terms of variance explanation. Boosted regression trees (BRT) models and path analysis showed that soil type and land cover were the most important controlling factors of soil quality, within which soil type had the greatest direct effect and land cover had the most indirect effect. Compared to MDS, TDS is a more sensitive method for assessing regional soil quality, especially in heterogeneous mountains. Soil type is the fundamental factor to determining soil quality. Vegetation and land cover indirectly modulate soil properties and soil quality.
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13
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Awad J, Fisk CA, Cox JW, Anderson SJ, van Leeuwen J. Modelling of THM formation potential and DOM removal based on drinking water catchment characteristics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 635:761-768. [PMID: 29710599 DOI: 10.1016/j.scitotenv.2018.04.149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/17/2018] [Accepted: 04/10/2018] [Indexed: 06/08/2023]
Abstract
UNLABELLED Catchment properties influence the character and concentration of dissolved organic matter (DOM). Surface and subsurface runoff from discrete catchments were collected and DOM was measured and assessed in terms of its treatability by Enhanced Coagulation and potential for disinfection by-product (trihalomethane, THMFP) formation potential. Models were developed of [1] DOM character [i.e. SUVA and SpCoL] and concentration (measured as dissolved organic carbon), [2] treatability of DOM by coagulation/flocculation processes and [3] specific THMFP based on the catchment features including: (a) surface and sub-surface soil texture (% clay: 5-25%), (b) topography (% slope: 5-15%) and (c) vegetation cover [i.e. high photosynthetic vegetation, low photosynthetic vegetation and bare soil] extracted from RapidEye satellite imagery using spectral mixture analysis. From these models, a catchment management decision support tool was designed for application by catchment managers to support decision-making of land-use and expected water quality related to water resources for drinking water supply. SOFTWARE AND DATA AVAILABILITY Data sets used for models developing presented in this paper have been published in Research Data Australia (RDA) under the title of "Impacts of catchment properties on DOM and nutrients in waters from drinking water catchments".1 These data sets are available in open access and published in June 2017. A catchment management decision support model (CMDSM) tool was developed. Macros created using Visual Basic for Applications in Excel 2010. Excel 2010 or higher is required to open the CMDSM tool. The tool is provided by the University of South Australia (UniSA) and is not currently available on-line so please contact the corresponding author for access or further information.
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Affiliation(s)
- John Awad
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia; Public Works Department, Faculty of Engineering, Mansoura University, Egypt.
| | - Claire A Fisk
- School of Biological Sciences, The University of Adelaide, North Terrace, South Australia, 5005, Australia
| | - Jim W Cox
- School of Biological Sciences, The University of Adelaide, North Terrace, South Australia, 5005, Australia; South Australian Research and Development Institute, Urrbrae 5064, South Australia, Australia
| | - Sharolyn J Anderson
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia
| | - John van Leeuwen
- School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia; Future Industries Institute, ITEE, University of South Australia, South Australia, 5095, Australia
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Stutter MI, Graeber D, Evans CD, Wade AJ, Withers PJA. Balancing macronutrient stoichiometry to alleviate eutrophication. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:439-447. [PMID: 29631134 DOI: 10.1016/j.scitotenv.2018.03.298] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/23/2018] [Accepted: 03/24/2018] [Indexed: 06/08/2023]
Abstract
Reactive nitrogen (N) and phosphorus (P) inputs to surface waters modify aquatic environments, affect public health and recreation. Source controls dominate eutrophication management, whilst biological regulation of nutrients is largely neglected, although aquatic microbial organisms have huge potential to process nutrients. The stoichiometric ratio of organic carbon (OC) to N to P atoms should modulate heterotrophic pathways of aquatic nutrient processing, as high OC availability favours aquatic microbial processing. Heterotrophic microbial processing removes N by denitrification and captures N and P as organically-complexed, less eutrophying forms. With a global data synthesis, we show that the atomic ratios of bioavailable dissolved OC to either N or P in rivers with urban and agricultural land use are often distant from a "microbial optimum". This OC-deficiency relative to high availabilities of N and P likely overwhelms within-river heterotrophic processing. We propose that the capability of streams and rivers to retain N and P may be improved by active stoichiometric rebalancing. Although autotrophic OC production contributes to heterotrophic rates substantial control on nutrient processing from allochthonous OC is documented for N and an emerging field for P. Hence, rebalancing should be done by reconnecting appropriate OC sources such as wetlands and riparian forests that have become disconnected from rivers concurrent with agriculture and urbanisation. However, key knowledge gaps require research prior to the safe implementation of this approach in management: (i) to evaluate system responses to catchment inputs of dissolved OC forms and amounts relative to internal production of autotrophic dissolved OC and aquatic and terrestrial particulate OC and (ii) evaluate risk factors in anoxia-mediated P desorption with elevated OC scenarios. Still, we find stoichiometric rebalancing through reconnecting landscape beneficial OC sources has considerable potential for river management to alleviate eutrophication, improve water quality and aquatic ecosystem health, if augmenting nutrient source control.
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Affiliation(s)
- M I Stutter
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
| | - D Graeber
- Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research, Magdeburg, Germany
| | - C D Evans
- Centre for Ecology and Hydrology, Environment Centre Wales, Bangor LL57 2UW, UK
| | - A J Wade
- Dept. of Archaeology, Geography and Environmental Science, University of Reading, Reading RG6 6AB, UK
| | - P J A Withers
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
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15
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Manninen N, Soinne H, Lemola R, Hoikkala L, Turtola E. Effects of agricultural land use on dissolved organic carbon and nitrogen in surface runoff and subsurface drainage. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 618:1519-1528. [PMID: 29128120 DOI: 10.1016/j.scitotenv.2017.09.319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/29/2017] [Accepted: 09/29/2017] [Indexed: 05/28/2023]
Abstract
Dissolved organic carbon (DOC) load in discharges from cultivated soils may have negative impacts on surface waters. The magnitude of the load may vary according to soil properties or agricultural management practices. This study quantifies the DOC load of cultivated mineral soils and investigates whether the load is affected by agricultural practices. Discharge volumes and concentrations of DOC and dissolved organic nitrogen (DON) were continually measured at three sites from surface runoff and artificial subsurface drainage or from combined total discharge over a two-year period (2012-2014). Two experimental sites in South-West Finland had clayey soils (with soil carbon contents of 2.7-5.9% in the topmost soil layer), and the third site in West-Central Finland had sandy soil (soil carbon contents of 4.3-6.2%). Permanent grassland, organic manure application, mineral fertilization, and conventional ploughing or no-till activities were studied. Furthermore, the biodegradable DOC pool of surface runoff and subsurface drainage water from no-till and ploughed fields was estimated in a 2-month incubation experiment with natural bacterial communities collected from the Baltic Sea seawater. The annual DOC and DON loads were affected by discharge volume and seasonal weather conditions. The loads varied between 25-52kgha-1 and 0.8-3.2kgha-1, respectively, and were comparable to those from boreal forests with similar soil types. The DOC load increased with increasing topsoil carbon content at all sites. There were slightly higher DOC concentrations and DOC load from permanent grassland, but otherwise we could not distinguish any clear management-induced differences in the total DOC loads. While only 6-17% of the DOC in discharge water was biologically degraded during the 2-month incubation, the proportion of biodegradable (labile) DOC in surface runoff appeared to increase when soil was ploughed compared to no-till.
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Affiliation(s)
- Noora Manninen
- University of Helsinki, Environmental soil science, P.O. Box 56, FI-00014 University of Helsinki, Finland.
| | - Helena Soinne
- University of Helsinki, Environmental soil science, P.O. Box 56, FI-00014 University of Helsinki, Finland
| | - Riitta Lemola
- Natural resources institute Finland, Humppilantie, FI-31600 Jokioinen, Finland
| | - Laura Hoikkala
- University of Helsinki, P.O. Box 65, FI-00014 University of Helsinki, Finland; Marine Research Centre, Finnish Environment Institute, Mustialankatu 1, FI-00790 Helsinki, Finland
| | - Eila Turtola
- Natural resources institute Finland, Humppilantie, FI-31600 Jokioinen, Finland
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Herlemann DPR, Manecki M, Dittmar T, Jürgens K. Differential responses of marine, mesohaline and oligohaline bacterial communities to the addition of terrigenous carbon. Environ Microbiol 2017; 19:3098-3117. [PMID: 28474480 DOI: 10.1111/1462-2920.13784] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 04/13/2017] [Accepted: 04/26/2017] [Indexed: 12/21/2022]
Abstract
In response to global warming, increasing quantities of tDOM are transported through estuaries from land to the sea. In this study, we investigated microbial responses to increased tDOM concentrations in three salinity regimes (salinity: 32, 7 and 3) characteristic of the Baltic Sea. Mesocosm experiments performed in May and November revealed low (0-6%) dissolved organic carbon (DOC) utilisation. Molecular DOM analyses using ultrahigh-resolution mass spectrometry identified the terrigenous signal in the tDOM manipulation, but the molecular changes in DOM levels over the course of the experiment were subtle. However, tDOM had significant stimulatory effects on bacterial production in the oligohaline mesocosms. The shift in the bacterial community composition was especially prominent in the tDOM-amended marine and mesohaline mesocosms, but not in the oligohaline mesocosms after 7 and 11 days of incubation. These results suggested the inherent ability of oligohaline bacterial communities to adapt to high tDOM concentrations and therefore to use tDOM. The higher rates of bacterial activity and DOC removal in mesocosms containing UV-pretreated tDOM supported the increased bioavailability of photoinduced, modified tDOM. The overall low rates of microbial tDOM utilisation highlights the importance of abiotic factors in determining the distribution and dynamics of tDOM in estuaries.
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Affiliation(s)
- D P R Herlemann
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Biological Oceanography, Seestrasse 15, Rostock, D-18119, Germany
| | - M Manecki
- Research Group for Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str, Oldenburg, 9-11 D-26129, Germany.,Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Marine Chemistry, Seestrasse 15, Rostock, D-18119, Germany
| | - T Dittmar
- Research Group for Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str, Oldenburg, 9-11 D-26129, Germany
| | - K Jürgens
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Biological Oceanography, Seestrasse 15, Rostock, D-18119, Germany
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