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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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2
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Klick SA, Pitula JS, Bryant RB, Collick AS, May EB, Pisani O. Natural sources and controlling factors of urea-nitrogen concentrations in agricultural drainage ditches. JOURNAL OF ENVIRONMENTAL QUALITY 2023; 52:984-998. [PMID: 37296522 DOI: 10.1002/jeq2.20498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/12/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
Agricultural drainage ditches accumulate high urea-nitrogen (N) concentrations even in the absence of urea fertilizer applications to adjacent crop fields. The accumulated urea, and other bioavailable forms of dissolved organic nitrogen (DON), can be flushed downstream during substantial rainfall events altering downstream water quality and phytoplankton communities. Sources of urea-N supporting its accumulation in agricultural drainage ditches are poorly understood. A ditch flooding event was simulated using mesocosms with N treatment solutions and monitored for changes in N concentrations, physicochemical properties, dissolved organic matter (DOM) composition, and N cycling enzymes. N concentrations were also monitored in field ditches after two rainfall events. Urea-N concentrations were higher with DON enrichment, but the treatment effects were temporary. The DOM released from the mesocosm sediments was dominated by terrestrial-derived, high molecular weight material. The lack of microbial-derived DOM and evidence from the bacterial gene abundances in the mesocosms suggests that urea-N accumulation after rainfall may not be associated with fresh biological inputs. The urea-N concentrations after spring rainfall and flooding with DON substrates indicated the urea from fertilizers may only temporarily affect urea-N concentrations in drainage ditches. Because urea-N concentrations increased with a high degree of DOM humification, sources of urea may derive from the slow decomposition of complex DOM structures. This study provides further insights of sources contributing to high urea-N concentrations and the types of DOM released from drainage ditches to nearby surface waters after hydrological events.
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Affiliation(s)
- Sabrina A Klick
- USDA-ARS, Southeast Watershed Research Laboratory, Tifton, Georgia, USA
| | - Joseph S Pitula
- Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland, USA
| | - Ray B Bryant
- USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, Pennsylvania, USA
| | - Amy S Collick
- Department of Agricultural Sciences, Morehead State University, Morehead, Kentucky, USA
| | - Eric B May
- Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland, USA
| | - Oliva Pisani
- USDA-ARS, Southeast Watershed Research Laboratory, Tifton, Georgia, USA
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3
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Liu Y, Hu Y, Yu C, Gao Y, Liu Z, Mostofa KMG, Li S, Hu Y, Yu G. Spatiotemporal optical properties of dissolved organic matter in a sluice-controlled coastal plain river with both salinity and trophic gradients. J Environ Sci (China) 2023; 129:1-15. [PMID: 36804226 DOI: 10.1016/j.jes.2022.09.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 06/18/2023]
Abstract
Due to the combined effect of sluices and sea tide, the sluice-controlled coastal plain river would be characterized by both trophic state and salinity gradients, affecting the spatiotemporal optical properties of dissolved organic matter (DOM). In this study, we investigated the spatiotemporal variation of water quality parameters and optical properties of DOM in the Haihe River, a representative sluice-controlled coastal plain river in Tianjin, China. A significant salinity gradient and four trophic states were observed in the water body of the Haihe River. Two humic- and one protein-like substances were identified from the DOM by the three-dimensional fluorescence spectra combined with the parallel factor (PARAFAC) analysis. Pearson's correlation analysis and redundancy analysis (RDA) showed that the salinity significantly affected the abundance of chromophoric DOM (CDOM) but did not cause significant changes in the fluorescence optical characteristics. In addition, the effect of Trophic state index (TSI) on the CDOM abundance was greater than that on the fluorescence intensity of fluorescent dissolved organic matter (FDOM). In the water body with both salinity and trophic state gradients, TSI posed a greater influence than salinity on the CDOM abundance. Our results fill the research gap in spatiotemporal DOM characteristics and water quality variation in water bodies with both salinity and trophic state gradients. These results are beneficial for clarifying the joint influence of saline intrusion and sluices on the DOM characteristics and water quality in sluice-controlled coastal plain rivers.
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Affiliation(s)
- Yu Liu
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Yucheng Hu
- Tianjin Hydraulic Science Research Institute, Tianjin 300061, China
| | - Chengxun Yu
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300191, China
| | - Yuqi Gao
- School of Mathematics, Tianjin University, Tianjin 300072, China
| | - Zhenying Liu
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300191, China
| | - Khan M G Mostofa
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Siliang Li
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Yumei Hu
- School of Mathematics, Tianjin University, Tianjin 300072, China
| | - Guanghui Yu
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
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4
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Wang X, Wu R, He Y. Field evidences of fluorescent dissolved organic matter (FDOM) as potential fingerprints for agricultural and urban sources in river environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27352-z. [PMID: 37155107 DOI: 10.1007/s11356-023-27352-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 04/26/2023] [Indexed: 05/10/2023]
Abstract
Field evidences of the fluorescence differences between agricultural and urban river reaches are still lack. In this study, the middle reaches of Danhe River (DH) and Mihe River (MH) in Shouguang, China, were designed as agricultural and urban river reaches, respectively, to compare the the fluorescence differences in disparate river reaches using excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC). Three fluorescence components were identified. C1 (Ex/Em=230,255,295 nm/420 nm) was categorized as humic-like fluorophores, C2 (Ex/Em=230,275 nm/330 nm) was recognized as tryptophan-like substances, and C3 (Ex/Em=215 nm/290 nm) was noted as tyrosine-like and phenylalanine-like compounds. The results showed that the FDOM posed significant differences between agricultural and urban river reaches (P < 0.001). The monitoring sites in DH were rich in C2 (1.90 ± 0.62 Raman Unit (RU), mean ± standard deviation), and the monitoring sites in MH were rich in C3 (1.32 ± 0.51 RU). Redundancy analysis revealed that C2 could be regarded as a fluorescence indicator of agricultural sewage in river environment, while C3 was recognized as a fluorescence indicator of domestic sewage in river environment. In conclusion, this study provided field evidences of FDOM as potential fingerprints for agricultural and urban sources in river environment.
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Affiliation(s)
- Xiangyu Wang
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Ruilin Wu
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
- Department of Ecology and Environment of Shanxi Province, Taiyuan, 030024, Shanxi, China
| | - Yong He
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
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5
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Shao T, Liang X, Zhuang D, Zheng K, Wang T. Seasonal variations in CDOM characteristics and effects of environmental factors in coastal rivers, Northeast China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:29052-29064. [PMID: 36401691 DOI: 10.1007/s11356-022-24165-4] [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: 06/22/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Colored dissolved organic matter (CDOM) is highly spatiotemporally varied due to the effects of complex environmental factors within a catchment or system. The seasonal nutritional status and potential risks of heavy metals in the coastal rivers of the Liaohe River basin were evaluated based on 40 water samples in January, April, May, and September. Meanwhile, the effects of environmental factors on CDOM, especially human activities, were quantitatively analyzed. The trophic state index (TSI) and the potential ecological risk index (RI) of heavy metals in the Liaohe River basin exhibited significant differences. The rivers were mesotrophic in January, lightly eutrophic in May, and highly eutrophic in April and September. An extremely high RI was shown in April and May, while a high RI was exhibited in September. CDOM exhibited great seasonal characteristics and showed significant seasonal correlations with environmental factors. Based on multiple general linear model analysis, total phosphorus (TP) was the most influential factor and significantly explained 62.1% of aCDOM(440) (p < 0.01) among the water parameters, followed by total alkalinity (38.3%). The percentages of built-up area exerted significantly positive effects on aCDOM(440) (R2 = 0.44), while distance from oil extraction sites significantly negatively affected aCDOM(440) (r = - 0.328, p < 0.05). Polluting enterprises showed non-significant correlation with CDOM (r = 0.314, p = 0.178).
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Affiliation(s)
- Tiantian Shao
- Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center On Yellow River Civilization, Henan University, Kaifeng, 475001, China
| | - Xiaowen Liang
- Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center On Yellow River Civilization, Henan University, Kaifeng, 475001, China
| | - Danyuan Zhuang
- Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center On Yellow River Civilization, Henan University, Kaifeng, 475001, China
| | - Ke Zheng
- School of Computer and Information Engineering, Henan University, Kaifeng, 475004, China
- , Kaifeng, China
| | - Tao Wang
- Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center On Yellow River Civilization, Henan University, Kaifeng, 475001, China
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Reinl KL, Harris TD, Elfferich I, Coker A, Zhan Q, De Senerpont Domis LN, Morales-Williams AM, Bhattacharya R, Grossart HP, North RL, Sweetman JN. The role of organic nutrients in structuring freshwater phytoplankton communities in a rapidly changing world. WATER RESEARCH 2022; 219:118573. [PMID: 35643062 DOI: 10.1016/j.watres.2022.118573] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/27/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Carbon, nitrogen, and phosphorus are critical macroelements in freshwater systems. Historically, researchers and managers have focused on inorganic forms, based on the premise that the organic pool was not available for direct uptake by phytoplankton. We now know that phytoplankton can tap the organic nutrient pool through a number of mechanisms including direct uptake, enzymatic hydrolysis, mixotrophy, and through symbiotic relationships with microbial communities. In this review, we explore these mechanisms considering current and projected future anthropogenically-driven changes to freshwater systems. In particular, we focus on how naturally- and anthropogenically- derived organic nutrients can influence phytoplankton community structure. We also synthesize knowledge gaps regarding phytoplankton physiology and the potential challenges of nutrient management in an organically dynamic and anthropogenically modified world. Our review provides a basis for exploring these topics and suggests several avenues for future work on the relation between organic nutrients and eutrophication and their ecological implications in freshwater systems.
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Affiliation(s)
- Kaitlin L Reinl
- Lake Superior National Estuarine Research Reserve, University of Wisconsin-Madison Division of Extension, 14 Marina Drive, Superior, Wisconsin 54880, US; University of Wisconsin-Madison, Center for Limnology, 608 N. Park St., Madison, WI, US; University of Minnesota-Duluth, Large Lakes Observatory, 2205 E. 5th St., Duluth, MN, US.
| | - Ted D Harris
- Kansas Biological Survey and Center for Ecological Research, 2101 Constant Ave., Lawrence, KS, US
| | - Inge Elfferich
- Cardiff University, Earth and Environmental Sciences, Main Building, Park Place CF10 3AT, Cardiff, UK
| | - Ayooluwateso Coker
- University of Minnesota-Duluth, Large Lakes Observatory, 2205 E. 5th St., Duluth, MN, US
| | - Qing Zhan
- Netherlands Institute of Ecology, Dept. of Aquatic Ecology, Droevendaalsesteeg 10, Wageningen, NL
| | | | - Ana M Morales-Williams
- University of Vermont, Rubenstein School of Environment and Natural Resources, 81 Carrigan Drive, Burlington, VT, US
| | - Ruchi Bhattacharya
- University of Waterloo, Department of Earth and Environmental Sciences, 200 University Ave., N2L 1V6, Waterloo, ON, CA
| | - Hans-Peter Grossart
- Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB), Dept. Plankton and Microbial Ecology, Zur alten Fischerhuette 2, D-16775 Stechlin, DE; Potsdam University, Institute of Biochemistry and Biology, Maulbeerallee 2, 14469 Potsdam
| | - Rebecca L North
- University of Missouri-Columbia, School of Natural Resources, 303L Anheuser Busch Natural Resource Building, Columbia, MO, US
| | - Jon N Sweetman
- Pennsylvania State University, Ecological Science and Management, 457 Agriculture Sciences and Industries Building, State College, PA, US
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Chen S, Du Y, Das P, Lamore AF, Dimova NT, Elliott M, Broadbent EN, Roebuck JA, Jaffé R, Lu Y. Agricultural land use changes stream dissolved organic matter via altering soil inputs to streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:148968. [PMID: 34280634 DOI: 10.1016/j.scitotenv.2021.148968] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/23/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Agricultural land use leads to significant changes in both the quality (e.g., sources and compositions) and quantity of dissolved organic matter (DOM) exported from terrestrial to aquatic ecosystems. However, the effect of agricultural activities often interacts with those of hydroclimatic drivers, making it difficult to delineate agriculture-induced changes and identify associated mechanisms. Using partial least square path modeling (PLS-PM), we examined the relative importance of agricultural land use, stream order, precipitation, and temperature in mediating allochthonous versus autochthonous sources and pathways that influenced stream DOM quality and quantity. We analyzed stream water DOM from 15 small streams draining watersheds across a gradient of agricultural land use in Southeast USA for about one year. For DOM quantity, agricultural land use increased the export of DOC and various DOM pools (terrestrial humic, microbial humic, and protein-like DOM) from land to streams, and for DOM quality, agricultural streams showed greater proportions of microbial humic compounds than forested streams. The PLS-PM model for DOM quantity accounted for 75.5% of total variance and identified that agricultural land use increased stream water DOM quantity primarily through increasing allochthonous inputs, which can be attributed to shallower flow paths in agricultural watersheds that enabled the export of organic materials from the upper, organic-rich soil horizon. PLS-PM models for DOM quality only explained ~13% of the total variance, highlighting the complex dynamics between environmental drivers and stream water DOM. Relative to commonly used multivariate statistic modeling (e.g., redundancy analysis (RDA)), PLS-PM models offer the advantages of identifying the primary pathway by which agricultural lands alter freshwater DOM and quantifying the relative importance of interactive effects of agriculture and hydroclimatic drivers. Therefore, structural equation modeling is a powerful tool that should be more widely adopted to distinguish among multiple drivers and mechanisms regulating freshwater biogeochemistry.
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Affiliation(s)
- Shuo Chen
- Department of Geological Sciences, University of Alabama, Tuscaloosa 35487, AL, USA
| | - YingXun Du
- Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008, China
| | - Parnab Das
- Department of Civil, Construction and Environmental Engineering, University of Alabama, Tuscaloosa 35487, AL, USA
| | - Alexander F Lamore
- Department of Geological Sciences, University of Alabama, Tuscaloosa 35487, AL, USA; Geosyntec Consultants, 19321 U.S. Highway 19 North Building C Suite 200, Clearwater, FL 33764, USA
| | - Natasha T Dimova
- Department of Geological Sciences, University of Alabama, Tuscaloosa 35487, AL, USA
| | - Mark Elliott
- Department of Civil, Construction and Environmental Engineering, University of Alabama, Tuscaloosa 35487, AL, USA
| | - Eben North Broadbent
- Spatial Ecology and Conservation (SPEC) Lab, University of Florida, Gainesville, FL 32611, USA
| | - Jesse Alan Roebuck
- Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA; Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Rudolf Jaffé
- Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - YueHan Lu
- Department of Geological Sciences, University of Alabama, Tuscaloosa 35487, AL, USA.
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Lee SC, Shin Y, Jeon YJ, Lee EJ, Eom JS, Kim B, Oh NH. Optical properties and 14C ages of stream DOM from agricultural and forest watersheds during storms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 272:116412. [PMID: 33433348 DOI: 10.1016/j.envpol.2020.116412] [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: 06/17/2020] [Revised: 09/30/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
Forest and agricultural land use affects the concentration and composition of dissolved organic carbon (DOC) in streams and rivers. To elucidate the impacts of forest and agricultural land use on stream DOC during storm events, we investigated DOC concentration ([DOC]), optical properties of dissolved organic matter (DOM), and Δ14C-DOC in both forest- and agriculture-dominated headwater streams in South Korea in the summer of 2012. One forested and five agricultural streams were investigated. During storms, the peak [DOC] of forest stream increased to 5.8 mg L-1, approximately two times larger than that of the most agricultural stream (3.2 mg L-1), demonstrating the weaker storm responses of the [DOC] of agricultural streams to hydrological change. Five PARAFAC components were identified, including three terrestrial humic-like substances (C1, C2, C3), one microbial humic substance (C4), and one microbial protein-like substances (C5). The mean (C4+C5)/(C1+C2+C3) of all storm events at the most agricultural stream was 1.5 times larger than that of the most forested stream, suggesting that more protein-like DOM is exported from agricultural watersheds. Whereas a forest stream was primarily composed of terrestrially derived and 14C-enriched modern DOC, the 14C-age of the most agricultural stream was up to ∼1000 years old. The results suggest that agricultural practices could decrease the old organic carbon pools from soils. However, how quickly the aged DOC can be degraded to CO2 in streams is unknown, warranting future investigation on lability of the aged DOC and their effects on CO2 evasion from rivers and estuaries downstream.
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Affiliation(s)
- Seung-Cheol Lee
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yera Shin
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, 08826, Republic of Korea
| | - Young-Joon Jeon
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun-Ju Lee
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jae-Sung Eom
- Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Bomchul Kim
- Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Neung-Hwan Oh
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, 08826, Republic of Korea; Environmental Planning Institute, Seoul National University, Seoul, 08826, Republic of Korea.
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9
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Available Dissolved Organic Carbon Alters Uptake and Recycling of Phosphorus and Nitrogen from River Sediments. WATER 2020. [DOI: 10.3390/w12123321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Concurrent with nutrient pollution, agriculture has significantly impacted the quantity, composition, and bioavailability of catchment-derived dissolved organic carbon (DOC) in stream ecosystems. Based on the stoichiometric theory, we tested the hypothesis that bioavailable DOC will stimulate the heterotrophic uptake of soluble reactive P (SRP) and inorganic nitrogen in stream sediments. In a simplified laboratory column flow-through study, we exposed stream sediments to additions of glucose, nitrate, and phosphate alone and in combination (+C, +NP, +CNP), and calculated gross and net changes in DOC and nutrients via a mass balance approach. Our results show that glucose-C increased nutrient uptake, but also that NP additions resulted in the enhanced consumption of both native and added organic C. The effects of C addition were stronger on N than P uptake, presumably because labile C stimulated both assimilation and denitrification, while part of the P uptake was due to adsorption. Internal cycling affected net nutrient uptake due to losses of dissolved organically-complexed P and N (DOP and DON). Overall, our study shows that increases in the stoichiometric availability of organic carbon can stimulate N and P sequestration in nutrient-polluted stream sediments. Future studies are required to assess the effects of complex organic carbon sources on nutrient uptake in stream sediments under different environmental conditions, and whether these stoichiometric relations are relevant for ecosystem management.
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Zhou Y, Xiao Q, Zhou L, Jang KS, Zhang Y, Zhang M, Lee X, Qin B, Brookes JD, Davidson TA, Jeppesen E. Are nitrous oxide emissions indirectly fueled by input of terrestrial dissolved organic nitrogen in a large eutrophic Lake Taihu, China? THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 722:138005. [PMID: 32208291 DOI: 10.1016/j.scitotenv.2020.138005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/09/2020] [Accepted: 03/15/2020] [Indexed: 06/10/2023]
Abstract
Lakes actively transform nitrogen (N) and emit disproportionately large amounts of N2O relative to their surface area. Studies have investigated the relative importance of denitrification or nitrification on N2O emissions; however, the linkage between N2O efflux and dissolved organic nitrogen (DON) and carbon (DOC) remains largely unknown. Long-term (2012-2017) seasonal field observations and a series of degradation experiments were used to unravel how DON composition impacts N2O emissions from Lake Taihu, China. In the northwestern part of the lake, large riverine inflow and high N2O emissions occur in all seasons (24.6 ± 25.2 μmol m-2 d-1), coincident with high levels of terrestrial DON and DOC here. The degradation of labile DON and DOC likely enhanced ammonification as supported by the correlations between NH4+-N and DON, DOC, a(350), and terrestrial humic-like C3. The area with large riverine inputs in the northwestern part of the lake was characterized by low DO which may enhance incomplete aerobic nitrification and incomplete denitrification, both leading to N2O production. Twenty days laboratory experiments indicated greater N2O production in the northwest inflow samples (N2O on day 20: 120.9 nmol L-1 and 17.3 nmol L-1 for bio- and photo-degradation samples, respectively) compared with the central lake samples (N2O on day 20: 20.3 nmol L-1 and 12.3 nmol L-1 for bio- and photo-degradation samples, respectively), despite both having low Chl-a. Our DON and DOC degradation experiments confirmed the occurrence of ammonification along with consumption of NH4+-N and thereafter NO3--N. Our results collectively suggest that terrestrial DON fueled ammonification, enhanced nitrification and incomplete denitrification, and thereby became an important contributor to the N2O efflux from Lake Taihu.
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Affiliation(s)
- Yongqiang Zhou
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qitao Xiao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Zhou
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kyoung-Soon Jang
- Biomedical Omics Center, Korea Basic Science Institute, Cheongju 28119, South Korea
| | - Yunlin Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Mi Zhang
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Xuhui Lee
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Boqiang Qin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Justin D Brookes
- Water Research Centre, Environment Institute, School of Biological Science, University of Adelaide, 5005 Adelaide, Australia
| | - Thomas A Davidson
- Department of Bioscience and Arctic Research Centre, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark
| | - Erik Jeppesen
- Department of Bioscience and Arctic Research Centre, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark; Sino-Danish Centre for Education and Research, Beijing 100190, China
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11
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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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12
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Pisani O, Bosch DD, Coffin AW, Endale DM, Liebert D, Strickland TC. Riparian land cover and hydrology influence stream dissolved organic matter composition in an agricultural watershed. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137165. [PMID: 32062270 DOI: 10.1016/j.scitotenv.2020.137165] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Dissolved organic matter (DOM) represents an essential component of the carbon cycle and controls biogeochemical and ecological processes in aquatic systems. The composition and reactivity of DOM are determined by the spatial distribution of its sources and its residence time in a watershed. While the effects of agricultural land cover on DOM quality have been reported across spatial and temporal scales, the influence of riparian land cover on stream DOM composition has received little attention. Furthermore, the combined effects of riparian land cover and streamflow rates on DOM composition require investigation. To this end, a multi-year (2016-2018) DOM characterization study was conducted using bi-weekly water samples collected from seven sub-watersheds nested within the Little River Experimental Watershed (LREW) near Tifton, Georgia, USA. DOM optical properties were determined to assess compositional variations using UV-Vis and excitation-emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor (PARAFAC) analysis. PARAFAC analysis indicated that DOM in the LREW was dominated by three humic-like fluorescing components of terrestrial, microbial, and anthropogenic origin and a protein-like component. DOM composition was influenced by riparian land cover and hydrology, and shifted towards recently produced, low molecular weight DOM with low aromaticity as the percentage of agricultural land within riparian wetlands increased. During periods of high discharge and high baseflow, the DOM pool was dominated by recalcitrant and terrestrial-derived material but shifted towards protein-like and microbial-derived with increasing cropland in the riparian area. The results of this two-year study indicate that the replacement of forested riparian buffers with agricultural land can result in altered DOM composition which may affect carbon cycling and downstream water quality in agricultural watersheds.
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Affiliation(s)
- Oliva Pisani
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA.
| | - David D Bosch
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA
| | - Alisa W Coffin
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA
| | - Dinku M Endale
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA
| | - Dan Liebert
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA
| | - Timothy C Strickland
- USDA-ARS, Southeast Watershed Research Laboratory, 2316 Rainwater Road, Tifton, GA 31793, USA
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13
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Tang J, Wang W, Yang L, Qiu Q, Lin M, Cao C, Li X. Seasonal variation and ecological risk assessment of dissolved organic matter in a peri-urban critical zone observatory watershed. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:136093. [PMID: 31863979 DOI: 10.1016/j.scitotenv.2019.136093] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/07/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
Peri-urban ecosystems are among the most intensive areas in terms of competition between different ecosystem components. Dissolved organic matter (DOM) plays a significant role in aquatic carbon cycling. The chemical composition of DOM and associated potential ecological risks in peri-urban aquatic ecosystems are poorly understood. Herein, we used fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC) to characterize DOM in a peri-urban critical zone observatory watershed in Eastern China. According to the theory of natural disaster risk formation, we calculated the ecological risk of DOM in the peri-urban watershed. Seasonal variation in DOM concentrations was observed, whereas fluorescent DOM concentrations were site-specific across four sub-watersheds. The analysis of DOM absorption properties revealed the presence of DOM components with high aromatic content and large molecular weight in the watershed. Four fluorescent components (two humic-like and two protein-like substances) were identified using the PARAFAC model. Spatial distribution analysis showed that DOM quality was mainly influenced by human activities, and the proportion of protein-like substance (C3) was strongly correlated with anthropogenic parameters. The distribution of optical indices indicated diverse sources of DOM in the watershed. Ecological risk related to DOM was greater in the dry season than the wet season. There was a slight risk in most areas, with an extreme risk in areas experiencing the most intensive human disturbance, which were also extremely or heavily vulnerable. The results emphasize the strong influence of human disturbance on the ecological risk of DOM in peri-urban aquatic ecosystems. Our study provides useful information for ecological risk assessment of DOM that is difficult to obtain using traditional chemical analysis.
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Affiliation(s)
- Jianfeng Tang
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Ningbo Urban Environment Observation and Research Station, Chinese Academy of Sciences, Ningbo 315800, China.
| | - Wendong Wang
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Yang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qianlinglin Qiu
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meixia Lin
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Changli Cao
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xinhu Li
- College of Architecture and Urban Planning, Tongji University, Shanghai 200082, China
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14
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Drake TW, Podgorski DC, Dinga B, Chanton JP, Six J, Spencer RGM. Land-use controls on carbon biogeochemistry in lowland streams of the Congo Basin. GLOBAL CHANGE BIOLOGY 2020; 26:1374-1389. [PMID: 31665558 DOI: 10.1111/gcb.14889] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
The flux and composition of carbon (C) from land to rivers represents a critical component of the global C cycle as well as a powerful integrator of landscape-level processes. In the Congo Basin, an expansive network of streams and rivers transport and cycle terrigenous C sourced from the largest swathe of pristine tropical forest on Earth. Increasing rates of deforestation and conversion to agriculture in the Basin are altering the current regime of terrestrial-to-aquatic biogeochemical cycling of C. To investigate the role of deforestation on dissolved organic and inorganic C (DOC and DIC, respectively) biogeochemistry in the Congo Basin, six lowland streams that drain catchments of varying forest proportion (12%-77%) were sampled monthly for 1 year. Annual mean concentrations of DOC exhibited an asymptotic response to forest loss, while DIC concentrations increased continuously with forest loss. The isotopic signature of DIC became significantly more enriched with deforestation, indicating a shift in source and processes controlling DIC production. The composition of dissolved organic matter (DOM), as revealed by ultra-high-resolution mass spectrometry, indicated that deforested catchments export relatively more aliphatic and heteroatomic DOM sourced from microbial biomass in soils. The DOM compositional results imply that DOM from the deforested sites is more biolabile than DOM from the forest, consistent with the corresponding elevated stream CO2 concentrations. In short, forest loss results in significant and comprehensive shifts in the C biogeochemistry of the associated streams. It is apparent that land-use conversion has the potential to dramatically affect the C cycle in the Congo Basin by reducing the downstream flux of stable, vascular-plant derived DOC while increasing the transfer of biolabile soil C to the atmosphere.
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Affiliation(s)
- Travis W Drake
- National High Magnetic Field Laboratory Geochemistry Group and Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, USA
- Department of Environmental Systems Science, ETH Zürich, Zurich, Switzerland
| | - David C Podgorski
- Department of Chemistry, Pontchartrain Institute for Environmental Sciences, University of New Orleans, New Orleans, LA, USA
| | - Bienvenu Dinga
- Institut de Recherche en Sciences et Exactes et Naturelles, Brazzaville, Republic of Congo
| | - Jeffrey P Chanton
- National High Magnetic Field Laboratory Geochemistry Group and Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, USA
| | - Johan Six
- Department of Environmental Systems Science, ETH Zürich, Zurich, Switzerland
| | - Robert G M Spencer
- National High Magnetic Field Laboratory Geochemistry Group and Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, USA
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15
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Bhattacharya R, Osburn CL. Spatial patterns in dissolved organic matter composition controlled by watershed characteristics in a coastal river network: The Neuse River Basin, USA. WATER RESEARCH 2020; 169:115248. [PMID: 31706125 DOI: 10.1016/j.watres.2019.115248] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 10/25/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
The effect of watershed characteristics (land use land cover and morphology) on spatial variability in dissolved organic matter (DOM) composition, and concentrations of dissolved organic carbon [DOC] and nitrogen [DON] was assessed in a coastal river basin draining into Pamlico Sound in eastern North Carolina, USA. Understanding the factors that influence DOM concentration and composition i.e., structurally complex molecules with high molecular weight versus low molecular weight, simple molecules can provide insights on DOM cycling and water composition implications. Such information is imperative for large coastal river networks undergoing rapid and intense land use and land cover (LULC) changes. DOM composition was estimated using optical indices calculated from DOM absorbance and fluorescence measurements. DOM was derived from terrestrial sources, and ordination analysis indicated that LULC, in particular, % wetland area was the most significant control on DOM composition and concentration. Wetland and agricultural coastal streams were abundant in humic and complex DOM, whereas forested and urban streams were least abundant in humic DOM. We speculate that greater availability of mobilizable DOM in wetland and agricultural watersheds contributed to this observation. In comparison, mixed urbanized and forested streams in North Carolina's Piedmont region were abundant in [DOC], less complex, low molecular weight DOM, as well as greater amounts [DON] due to higher urban runoff and elevated DOM production in these streams. Our results indicated that physiographic transition from Piedmont to coastal plain and varying LULC influenced the spatial variability in DOM composition and concentration. Our findings highlight that increasing anthropogenic alterations might increase the abundance of reactive DOM in coastal rivers and estuaries resulting in severe water quality issues. This information is important for monitoring and developing land use policies.
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Affiliation(s)
- Ruchi Bhattacharya
- School of Natural Resources, University of Missouri, Columbia, MO, USA; Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA.
| | - Christopher L Osburn
- Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
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16
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Li X, Rao NRH, Linge KL, Joll CA, Khan S, Henderson RK. An evaluation of measurement techniques for algal-derived organic nitrogen. WATER RESEARCH 2019; 165:114998. [PMID: 31470284 DOI: 10.1016/j.watres.2019.114998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/11/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
Algal-derived organic matter (AOM) from algal blooms in water supply systems contains dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) among other constituents. The DON and DOC are disinfection by-product (DBP) precursor compounds, and must be well characterised to facilitate effective removal, thus minimising DBP formation during disinfection. While DOC character has been studied extensively, DON analysis suffers from inaccuracies due to sample pre-treatment and instrument sensitivities. A liquid chromatography method that combines size exclusion chromatography with highly sensitive organic carbon and nitrogen detectors (LC-OCND) has been widely adopted for DOC analysis; however, its potential for application for DON charactersation has been suggested as a viable alternative to existing DON characterisation techniquesnot been assessed despite its potential. Hence, the aim was to compare the effectiveness of conventional total dissolved N-dissolved inorganic N (TN-DIN), and LC-OCND methods for analysing DON in AOM. A suite of N-containing model compounds representative of DON and AOM extracted from Chlorella vulgaris CS-42/7 and Microcystis aeruginosa CS-555/1 were used to evaluate the techniques. The DON of both model compounds and AOM was first analysed using the conventional method and, then, via LC-OCND. It was observed that LC-OCND had a better precision for DON when TN contained more DIN. LC-OCND provided direct quantitative measurements for bulk and fractionated DON and DIN, with little interference caused by DIN. Additionally, LC-OCND provided information on MW distribution and protein content of the AOM. For example, LC-OCND results showed that M. aeruginosa AOM contained more HMW material than C. vulgaris AOM. However, as LC-OCND uses UV oxidation, it could not completely oxidise complex aromatic structures, and thus had a lower recovery for HMW model compounds and algal DON in comparison to the conventional method that used high temperature catalytic oxidation. Overall, it is advised that a combination of LC-OCND and TN analysis be used to provide a more detailed characterisation of N-containing AOM and other similar HMW aquatic NOM samples.
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Affiliation(s)
- X Li
- AOM Lab, School of Chemical Engineering, The University of New South Wales, Sydney, Australia
| | - N R H Rao
- AOM Lab, School of Chemical Engineering, The University of New South Wales, Sydney, Australia
| | - K L Linge
- Curtin Water Quality Research Centre, Chemistry, School of Molecular and Life Sciences, Curtin University, Perth, Australia; ChemCentre, Perth, Australia
| | - C A Joll
- Curtin Water Quality Research Centre, Chemistry, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - S Khan
- UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia
| | - R K Henderson
- AOM Lab, School of Chemical Engineering, The University of New South Wales, Sydney, Australia.
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17
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Hu H, Shi Y, Liao K, Ma H, Xu K, Ren H. Effect of temperature on the characterization of soluble microbial products in activated sludge system with special emphasis on dissolved organic nitrogen. WATER RESEARCH 2019; 162:87-94. [PMID: 31255784 DOI: 10.1016/j.watres.2019.06.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/18/2019] [Accepted: 06/13/2019] [Indexed: 06/09/2023]
Abstract
Previous research has focused on dissolved organic carbon (DOC) as a surrogate for soluble microbial products (SMPs) and found that temperature has a significant influence on the production of SMP-based DOC (SDOC) during biological processes. Little is known about the SMP-based dissolved organic nitrogen (SDON), although some nitrogenous organic matter has been identified as an important part of SMPs. This study investigated the effect of temperature (8 °C, 15 °C and 25 °C) on the characterization of SMPs in an activated sludge system with special emphasis on SDON. Results showed the positive effect of reduced temperature on SDON production. Fluorescence spectroscopy and ultrahigh-resolution mass spectrometry showed the produced SDON at 8 °C and 15 °C exhibits more lability than at 25 °C. This was also supported by the algal bioassay, indicating the SDON produced at low temperature is highly bioavailable and prone to stimulate algae and microorganisms. In addition, principal component analysis demonstrated that the effect of temperature on the chemical characterization of SDON is different from that of SDOC. Overall, this study highlights the importance of SDON control during biological processes at a low temperature to reduce the potential impact of effluent SMPs on receiving waters or wastewater reuse.
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Affiliation(s)
- Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Yuanji Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Kewei Liao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Haijun Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
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18
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Hui C, Liu B, Wei R, Jiang H, Zhao Y, Liang Y, Zhang Q, Xu L. Dynamics, biodegradability, and microbial community shift of water-extractable organic matter in rice-wheat cropping soil under different fertilization treatments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 249:686-695. [PMID: 30933766 DOI: 10.1016/j.envpol.2019.03.091] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/20/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Although fertilization plays an important role in determining the contents of soil dissolved organic matters or water-extractable organic matter (DOM, WEOM), knowledge regarding the dynamics, biodegradability, and microbial community shifts of WEOM in response to different fertilization treatments is very limited, particularly in rice-wheat cropping soil. Thus, in the present study, we performed biodegradation experiments using WEOM extracted from samples of soil that had been subjected to four different fertilization treatments: unfertilized control (CK), chemical fertilizer (CF), 50% chemical fertilizer plus pig manure (PMCF), and 100% chemical fertilizer plus rice straw (SRCF). UV spectrum and fluorescence 3D excitation-emission matrix analyses applied to investigate the chemical composition of WEOM revealed that all examined WEOMs were derived from microbial activity and the dominant portion comprised humic acid-like compounds. After the incubation, 31.17, 31.63, 43.47, and 33.01% of soil WEOM from CK, CF, PMCF, and SRCF treatments, respectively, were biodegraded. PMCF- derived WEOM had the highest biodegradation rate. High-throughput sequencing analyses performed to determine the microbial community before and after the incubation indicated that Sphingomonas, Bacillus, and Flavisolibacter were the predominant bacterial genera in the original inoculum derived from the four fertilization treatments. Following biodegradation, we observed that the dominant bacteria differed according to fertilization treatments: Curvibacter (43.25%) and Sphingobium (10.47%) for CK, Curvibacter (29.68%) and Caulobacter (20.00%) for CF, Azospirillum (23.68%) and Caulobacter (13.29%) for PMCF, and Ralstonia (51.75%) for SRCF. Canonical correspondence analysis revealed that, shifts in the microbial community were closely correlated with pH and specific UV absorbance at 254 nm. We speculated that the inherent traits of different WEOM and the properties of soil solutions under different fertilization treatments shaped the soil microbial community structure, thereby influencing the biodegradation of WEOM.
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Affiliation(s)
- Cai Hui
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Bing Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Ran Wei
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Hui Jiang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yuhua Zhao
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yongchao Liang
- Institute of Soil and Water Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Qichun Zhang
- Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Ligen Xu
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.
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Wu Z, Wu W, Lin C, Zhou S, Xiong J. Deciphering the origins, composition and microbial fate of dissolved organic matter in agro-urban headwater streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 659:1484-1495. [PMID: 31096358 DOI: 10.1016/j.scitotenv.2018.12.237] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 12/15/2018] [Accepted: 12/15/2018] [Indexed: 06/09/2023]
Abstract
Landscape urbanization and intensive agriculture dramatically alter stream ecosystems, but it is little known how urban and agriculture land use change the quantity, quality and ultimate fate of dissolved organic matter (DOM) in stream ecosystems via nonpoint source pathways. Size-exclusion chromatography with fluorescence excitation-emission matrices, as well as absorbance and lignin biomarkers were applied to investigate the characteristics and microbial fate of DOM in 15 first-order agricultural, urban and forest headwater streams in Taihu Lake Watershed, a subtropical region of SE China. Results showed that both urban and agricultural land cover increased the amount of dissolved organic matter (DOC) with a lower C/N ratio, and that the majority of DOC was bound to terrestrial humic-like substances. Compared to forest-impacted headwater streams, the aromaticity and molecularity of OM were greatly decreased as the amounts of anthropogenic/aquagenic fulvic acid-like and protein-like DOM enriched in urban streams, and that of microbially soil-derived humic-like DOM and low molecular-weight substances (e.g., neutrals and acids) increased in agricultural streams, respectively. Human-influenced land use also influenced the seasonal variability of stream DOM biogeochemistry. Natural watersheds produced high DOC specific loads and concentrations only in the rainy season (high-flow period). Agricultural streams contributed a higher amount of terrestrial humic-like and protein-like fractions and urbanized watersheds had high values of autochthonous protein-like fractions only. Redundancy analysis (RDA) revealed that DOM quality (explainable variables: molecular source, 43.29%; molecular-weight, 29.74%) were the most prominent factor impacting microbial carbon processing, followed by inorganic nutrients (17.29%). A higher proportion of DOM from urban streams was eventually mineralized to carbon dioxide mainly due to the inefficient utilization of humic and nonhumic (e.g., protein, polysaccharides and lignin) substances as well as higher levels of inorganic nitrogen and phosphorus, whereas a significant fraction of DOM from agricultural and forest streams tended to enter microbial production and the recalcitrant-DOM pool due to the presence of less labile substrates. Our findings indicate that differences in stream-DOM and environmental properties due to urbanization and farming practices may influence stream microbial carbon processing and cause bottom-up changes in the fate of organic carbon moving through freshwater ecosystems.
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Affiliation(s)
- Zhipeng Wu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Weidong Wu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
| | - Chen Lin
- Key Laboratory of Watershed Geographic Sciences, Institute of Geography and Limnology, Chinese Academy Sciences, Nanjing 210008, China.
| | - Shenglu Zhou
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210046, China.
| | - Junfeng Xiong
- Key Laboratory of Watershed Geographic Sciences, Institute of Geography and Limnology, Chinese Academy Sciences, Nanjing 210008, China; School of Geography and Remote Sensing, Nanjing University of Information Science & Technology, Nanjing 210044, China
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20
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Zhang Y, Liang X. Understanding Organic Nonpoint-Source Pollution in Watersheds via Pollutant Indicators, Disinfection By-Product Precursor Predictors, and Composition of Dissolved Organic Matter. JOURNAL OF ENVIRONMENTAL QUALITY 2019; 48:102-116. [PMID: 30640343 DOI: 10.2134/jeq2018.06.0228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The analytical techniques and instrumentation used to assess agricultural and rural nonpoint-source organic pollution loading are usually complex and expensive. There has been a strong demand for alternative methodologies to determine the presence and composition of organic pollutants and to predict their levels. In the current work, we investigated a simple and inexpensive approach combining excitation-emission matrix and support vector machine that measures pollution and predicts the levels of precursors to disinfection by-products, which are organic pollutants derived from agricultural and rural nonpoint sources in small watersheds. Through parallel factor analysis, a four-component model was developed to explain the composition of dissolved organic matter in water impacted by nonpoint-source pollution. Support vector classification and support vector regression with model components can use fluorescence properties as proxy indicators for nonpoint-source pollution. When the model components are used as input variables, formation potential of disinfection by-products can be predicted. This method provides water utilities managers with tools to control pollution, supervise aquatic environments, and ensure the safety of drinking water.
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21
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Wang B, Liu C, Chen Y, Dong F, Chen S, Zhang D, Zhu J. Structural characteristics, analytical techniques and interactions with organic contaminants of dissolved organic matter derived from crop straw: a critical review. RSC Adv 2018; 8:36927-36938. [PMID: 35558903 PMCID: PMC9089241 DOI: 10.1039/c8ra06978f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/25/2018] [Indexed: 11/21/2022] Open
Abstract
Dissolved organic matter (DOM) represents one of the most mobile and reactive organic compounds in an ecosystem and plays an important role in the fate and transport of soil organic pollutants, nutrient cycling and more importantly global climate change. Advances in environment geochemistry in the past two decades have improved our knowledge about the genesis, composition, and structure of DOM, and its effect on the environment. Application of analytical technology, for example UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR) spectroscopy, and three-dimensional fluorescence spectroscopy (3D-EEM) have resulted in these advances. At present, crop straw, as a part of energy development strategy, is mainly used for soil amendment, fodder, fertilizer and industrial materials. Moreover, the fermentation and decomposition of straw should be also promoted for ecological agriculture. However, few studies have focused on the structural properties of DOM derived from crop straw in farmland soil. In this article, DOM derived from crop straw, which is abbreviated to "CDOM", presents active physicochemical properties that can affect the migration and bioavailability of organic contaminants (OCs) in terrestrial ecosystems. The objectives of this review paper are: (i) to discuss the structural characteristics, analytical techniques and interactions between CDOM and OCs in farmland soil; (ii) to present a critical analysis of the impact of CDOM on the physicochemical transformation and transport of OCs in farmland soils; (iii) to provide the perspectives in future research. Therefore, the findings obtained from this study can be utilized to evaluate the relations of interactions between CDOM and OCs in agricultural soils, in order to support some suggestions for future development in agricultural waste recycling, buffering of organic pollution, and the effect on the global carbon cycle.
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Affiliation(s)
- Bin Wang
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology Sichuan 621010 PR China
| | - Chang Liu
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology Sichuan 621010 PR China
| | - Yuwei Chen
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Department of Chemistry and Biochemistry, Laurentian University Sudbury P3E 2C6 Canada
| | - Faqin Dong
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology Sichuan 621010 PR China
| | - Shu Chen
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology Sichuan 621010 PR China
| | - Di Zhang
- Faculty of Environment Science and Engineering, Kunming University of Science and Technology Yunnan 650500 PR China +86 15887215550
| | - Jingping Zhu
- School of Environment and Resource, Southwest University of Science and Technology Sichuan 621010 PR China +86 816 2419018 +86 816 2419018
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology Sichuan 621010 PR China
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22
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Li L, He ZL, Tfaily MM, Inglett P, Stoffella PJ. Spatial-temporal variations of dissolved organic nitrogen molecular composition in agricultural runoff water. WATER RESEARCH 2018; 137:375-383. [PMID: 29555116 DOI: 10.1016/j.watres.2018.01.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/09/2018] [Accepted: 01/14/2018] [Indexed: 06/08/2023]
Abstract
Leaching of dissolved organic nitrogen (DON) has been reported as a pathway of N loss from agriculture, but the molecular composition of DON in agricultural water is poorly understood. Runoff water samples were collected from citrus grove furrows (CGF), ditches (CGD) and pasture ditches (PD) in four seasons. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used to investigate molecular composition of DON. Chemodiversity index of DON had spatiotemporal variations, while the molecular composition of total DON showed minimal variations, except for PD in November. Lignin derivatives constituted 61% of the total DON compounds. Relative abundance of aliphatic compounds, char and condensed aromatics of unique DON compounds varied spatiotemporally and had a significant correlation with DON concentration. Aromaticity index decreased from CGF to connected CGD, implying that photodegradation is possibly the dominant process that alters molecular composition of aquatic DON during the transport. Significant differences in unique DON composition between CGD and PD indicates that fertilization and land use affect DON composition. The information on molecular characterization of DON should be useful for tracking DON source and developing technologies to remove DON in the agricultural runoff water.
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Affiliation(s)
- Liguang Li
- University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL, 34945, USA
| | - Zhenli L He
- University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL, 34945, USA.
| | - Malak M Tfaily
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Patrick Inglett
- Soil and Water Sciences Department, University of Florida, Gainesville, FL, 32608, USA
| | - Peter J Stoffella
- University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL, 34945, USA
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23
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Oladeinde A, Lipp E, Chen CY, Muirhead R, Glenn T, Cook K, Molina M. Transcriptome Changes of Escherichia coli, Enterococcus faecalis, and Escherichia coli O157:H7 Laboratory Strains in Response to Photo-Degraded DOM. Front Microbiol 2018; 9:882. [PMID: 29867797 PMCID: PMC5953345 DOI: 10.3389/fmicb.2018.00882] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/17/2018] [Indexed: 11/26/2022] Open
Abstract
In this study, we investigated gene expression changes in three bacterial strains (Escherichia coli C3000, Escherichia coli O157:H7 B6914, and Enterococcus faecalis ATCC 29212), commonly used as indicators of water quality and as control strains in clinical, food, and water microbiology laboratories. Bacterial transcriptome responses from pure cultures were monitored in microcosms containing water amended with manure-derived dissolved organic matter (DOM), previously exposed to simulated sunlight for 12 h. We used RNA sequencing (RNA-seq) and quantitative real-time reverse transcriptase (qRT-PCR) to compare differentially expressed temporal transcripts between bacteria incubated in microcosms containing sunlight irradiated and non-irradiated DOM, for up to 24 h. In addition, we used whole genome sequencing simultaneously with RNA-seq to identify single nucleotide variants (SNV) acquired in bacterial populations during incubation. These results indicate that E. coli and E. faecalis have different mechanisms for removal of reactive oxygen species (ROS) produced from irradiated DOM. They are also able to produce micromolar concentrations of H2O2 from non-irradiated DOM, that should be detrimental to other bacteria present in the environment. Notably, this study provides an assessment of the role of two conjugative plasmids carried by the E. faecalis and highlights the differences in the overall survival dynamics of environmentally-relevant bacteria in the presence of naturally-produced ROS.
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Affiliation(s)
- Adelumola Oladeinde
- National Exposure Research Laboratory, Student Volunteer, U.S. Environmental Protection Agency, Office of Research and Development, Athens, GA, United States.,Department of Environmental Health Science, University of Georgia, Athens, GA, United States
| | - Erin Lipp
- Department of Environmental Health Science, University of Georgia, Athens, GA, United States
| | - Chia-Ying Chen
- National Exposure Research Laboratory, National Research Council Associate, U.S. Environmental Protection Agency, Office of Research and Development, Athens, GA, United States
| | | | - Travis Glenn
- Department of Environmental Health Science, University of Georgia, Athens, GA, United States
| | - Kimberly Cook
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, United States Department of Agriculture, Athens, GA, United States
| | - Marirosa Molina
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Office of Research and Development, Athens, GA, United States
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24
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Graeber D, Poulsen JR, Heinz M, Rasmussen JJ, Zak D, Gücker B, Kronvang B, Kamjunke N. Going with the flow: Planktonic processing of dissolved organic carbon in streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 625:519-530. [PMID: 29291566 DOI: 10.1016/j.scitotenv.2017.12.285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/22/2017] [Accepted: 12/23/2017] [Indexed: 06/07/2023]
Abstract
A large part of the organic carbon in streams is transported by pulses of terrestrial dissolved organic carbon (tDOC) during hydrological events, which is more pronounced in agricultural catchments due to their hydrological flashiness. The majority of the literature considers stationary benthic biofilms and hyporheic biofilms to dominate uptake and processing of tDOC. Here, we argue for expanding this viewpoint to planktonic bacteria, which are transported downstream together with tDOC pulses, and thus perceive them as a less variable resource relative to stationary benthic bacteria. We show that pulse DOC can contribute significantly to the annual DOC export of streams and that planktonic bacteria take up considerable labile tDOC from such pulses in a short time frame, with the DOC uptake being as high as that of benthic biofilm bacteria. Furthermore, we show that planktonic bacteria efficiently take up labile tDOC which strongly increases planktonic bacterial production and abundance. We found that the response of planktonic bacteria to tDOC pulses was stronger in smaller streams than in larger streams, which may be related to bacterial metacommunity dynamics. Furthermore, the response of planktonic bacterial abundance was influenced by soluble reactive phosphorus concentration, pointing to phosphorus limitation. Our data suggest that planktonic bacteria can efficiently utilize tDOC pulses and likely determine tDOC fate during downstream transport, influencing aquatic food webs and related biochemical cycles.
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Affiliation(s)
| | | | | | | | - Dominik Zak
- Aarhus University, Denmark; Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany; University of Rostock, Germany
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25
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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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26
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Heinz M, Zak D. Storage effects on quantity and composition of dissolved organic carbon and nitrogen of lake water, leaf leachate and peat soil water. WATER RESEARCH 2018; 130:98-104. [PMID: 29202346 DOI: 10.1016/j.watres.2017.11.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/23/2017] [Accepted: 11/25/2017] [Indexed: 06/07/2023]
Abstract
This study aimed to evaluate the effects of freezing and cold storage at 4 °C on bulk dissolved organic carbon (DOC) and nitrogen (DON) concentration and SEC fractions determined with size exclusion chromatography (SEC), as well as on spectral properties of dissolved organic matter (DOM) analyzed with fluorescence spectroscopy. In order to account for differences in DOM composition and source we analyzed storage effects for three different sample types, including a lake water sample representing freshwater DOM, a leaf litter leachate of Phragmites australis representing a terrestrial, 'fresh' DOM source and peatland porewater samples. According to our findings one week of cold storage can bias DOC and DON determination. Overall, the determination of DOC and DON concentration with SEC analysis for all three sample types were little susceptible to alterations due to freezing. The findings derived for the sampling locations investigated here may not apply for other sampling locations and/or sample types. However, DOC size fractions and DON concentration of formerly frozen samples should be interpreted with caution when sample concentrations are high. Alteration of some optical properties (HIX and SUVA254) due to freezing were evident, and therefore we recommend immediate analysis of samples for spectral analysis.
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Affiliation(s)
- Marlen Heinz
- Department of Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587 Berlin, Germany; Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Königin-Luise-Str. 19, 14195 Berlin, Germany.
| | - Dominik Zak
- Department of Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587 Berlin, Germany; Faculty of Agriculture and Environment, Landscape Ecology and Site Evaluation, University of Rostock, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany; Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark
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27
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Taube R, Ganzert L, Grossart HP, Gleixner G, Premke K. Organic matter quality structures benthic fatty acid patterns and the abundance of fungi and bacteria in temperate lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:469-481. [PMID: 28818662 DOI: 10.1016/j.scitotenv.2017.07.256] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/27/2017] [Accepted: 07/29/2017] [Indexed: 05/25/2023]
Abstract
Benthic microbial communities (BMCs) play important roles in the carbon cycle of lakes, and benthic littoral zones in particular have been previously highlighted as biogeochemical hotspots. Dissolved organic matter (DOM) presents the major carbon pool in lakes, and although the effect of DOM composition on the pelagic microbial community composition is widely accepted, little is known about its effect on BMCs, particularly aquatic fungi. Therefore, we investigated the composition of benthic littoral microbial communities in twenty highly diverse lakes in northeast Germany. DOM quality was analyzed via size exclusion chromatography (SEC), fluorescence parallel factor analyses (PRAFACs) and UV-Vis spectroscopy. We determined the BMC composition and biomass using phospholipid-derived fatty acids (PLFA) and extended the interpretation to the analysis of fungi by applying a Bayesian mixed model. We present evidence that the quality of DOM structures the BMCs, which are dominated by heterotrophic bacteria and show low fungal biomass. The fungal biomass increases when the DOM pool is processed by microorganisms of allochthonous origin, whereas the opposite is true for bacteria.
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Affiliation(s)
- Robert Taube
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Chemical Analytics and Biogeochemistry, 12587 Berlin, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, 15374 Müncheberg, Germany.
| | - Lars Ganzert
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Experimental Limnology, 16775 Stechlin, Germany
| | - Hans-Peter Grossart
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Experimental Limnology, 16775 Stechlin, Germany; Potsdam University, Institute for Biochemistry and Biology, 14469 Potsdam, Germany
| | - Gerd Gleixner
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Katrin Premke
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Chemical Analytics and Biogeochemistry, 12587 Berlin, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, 15374 Müncheberg, Germany
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28
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Massicotte P, Asmala E, Stedmon C, Markager S. Global distribution of dissolved organic matter along the aquatic continuum: Across rivers, lakes and oceans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 609:180-191. [PMID: 28738200 DOI: 10.1016/j.scitotenv.2017.07.076] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 05/12/2023]
Abstract
Based on an extensive literature survey containing more than 12,000 paired measurements of dissolved organic carbon (DOC) concentrations and absorption of chromophoric dissolved organic matter (CDOM) distributed over four continents and seven oceans, we described the global distribution and transformation of dissolved organic matter (DOM) along the aquatic continuum across rivers and lakes to oceans. A strong log-linear relationship (R2=0.92) between DOC concentration and CDOM absorption at 350nm was observed at a global scale, but was found to be ecosystem-dependent at local and regional scales. Our results reveal that as DOM is transported towards the oceans, the robustness of the observed relation decreases rapidly (R2 from 0.94 to 0.44) indicating a gradual decoupling between DOC and CDOM. This likely reflects the decreased connectivity between the landscape and DOM along the aquatic continuum. To support this hypothesis, we used the DOC-specific UV absorbance (SUVA) to characterize the reactivity of the DOM pool which decreased from 4.9 to 1.7m2 × gC-1 along the aquatic continuum. Across the continuum, a piecewise linear regression showed that the observed decrease of SUVA occurred more rapidly in freshwater ecosystems compared to marine water ecosystems, suggesting that the different degradation processes act preferentially on CDOM rather than carbon content. The observed change in the DOM characteristics along the aquatic continuum also suggests that the terrestrial DOM pool is gradually becoming less reactive, which has profound consequences on cycling of organic carbon in aquatic ecosystems.
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Affiliation(s)
- Philippe Massicotte
- Aarhus University, Department of Bioscience, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
| | - Eero Asmala
- Aarhus University, Department of Bioscience, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Colin Stedmon
- Technical University of Denmark, National Institute for Aquatic Resources, Section for Marine Ecology and Oceanography, Kavalergården 6, 2920 Charlottenlund, Denmark
| | - Stiig Markager
- Aarhus University, Department of Bioscience, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
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29
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Jiang T, Kaal J, Liang J, Zhang Y, Wei S, Wang D, Green NW. Composition of dissolved organic matter (DOM) from periodically submerged soils in the Three Gorges Reservoir areas as determined by elemental and optical analysis, infrared spectroscopy, pyrolysis-GC-MS and thermally assisted hydrolysis and methylation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017. [PMID: 28641186 DOI: 10.1016/j.scitotenv.2017.06.114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Soil-derived dissolved organic matter (DOM) has a major influence in biogeochemical processes related to contaminant dynamics and greenhouse gas emissions, due to its reactivity and its bridging role between the soil and aquatic systems. Within the Three Gorges Reservoir (TGR, China) area, an extensive water-fluctuation zone periodically submerges the surrounding soils. Here we report a characterization study of soil-derived DOM across the TGR areas, using elemental and optical analysis, infrared spectroscopy (FTIR), pyrolysis-GC-MS (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS). The results showed that the soil DOM from the TGR area is a mixture of "allochthonous" (i.e., plant-derived/terrigenous) and "autochthonous" (i.e., microbial) origins. The terrigenous DOM is composed primarily of phenolic and aliphatic structures from lignin and aliphatic biopolymers (i.e. cutin, suberin), respectively. Multivariate statistics differentiated between two fractions of the microbial DOM, i.e. chitin-derived, perhaps from fungi and arthropods in soil, and protein-derived, partially sourced from algal or aquatic organisms. Molecular proxies of source and degradation state were in good agreement with optical parameters such as SUVA254, the fluorescence index (FI) and the humification index (HIX). The combined use of elemental analysis, fluorescence spectroscopy, and Py-GC-MS provides rigorous and detailed DOM characterization, whereas THM-GC-MS is useful for more precise but qualitative identification of the different phenolic (cinnamyl, p-hydroxyphenyl, guaiacyl, syringyl and tannin-derived) and aliphatic materials. With the multi-methodological approach used in this study, FTIR was the least informative, in part, because of the interference of inorganic matter in the soil DOM samples. The soil DOM from the TGR's water fluctuation zone exhibited considerable compositional diversity, mainly related to the balance between DOM source (microbial- or plant-derived), local vegetation and anthropogenic activities (e.g., agriculture). Finally, the relationship between DOM composition and its potential reactivity with substances of environmental concerns in the TGR area are also discussed.
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Affiliation(s)
- Tao Jiang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, 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.
| | - Joeri Kaal
- Ciencia do Sistema Terra, Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, Campus Sur s/n, Santiago de Compostela 15782, Spain; Instituto de Ciencias del Patrimonio (Incipit), Consejo Superior de Investigaciones Científicas (CSIC), Avda. de Vigo sn, 15705 Santiago de Compostela, Spain
| | - Jian Liang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Yaoling Zhang
- Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China
| | - Shiqiang Wei
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Dingyong Wang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Nelson W Green
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
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30
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Sui X, Wu Z, Lin C, Zhou S. Terrestrially derived glomalin-related soil protein quality as a potential ecological indicator in a peri-urban watershed. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:315. [PMID: 28589455 DOI: 10.1007/s10661-017-6012-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 05/21/2017] [Indexed: 06/07/2023]
Abstract
Glomalin, which sequesters substantial amounts of carbon, plays a critical role in sustaining terrestrial biome functions and contributes to the fate of many pollutants from terrestrial to aquatic ecosystems. Despite having focused on the amount of glomalin produced, very few attempts have been made to understand how landscapes and environmental conditions influence glomalin composition and characteristics. This study focused on glomalin-related soil protein (GRSP) exported as storm runoff including eroded sediment and water that was collected before flowing to surface waters in a peri-urban watershed. GRSP characteristics were assessed by Bradford protein analysis, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC), and the determination of aromaticity based on the specific ultraviolet absorption value (280 nm) and molecular weight. General linear models (GLMs) was established by integrating microbial activity, land cover, water temperature, precipitation, and other solution chemical properties to explain the variations in GRSP characteristics. Results showed that a higher GRSP concentration in agricultural reference sites was produced in the form of specific materials with low molecular weight and aromaticity, as well as high percentage of C1 and C5 components which indicate microbial-processed sources, relative to urbanized and forested sites. Compared with forested land, urbanized land clearly produced runoff GRSP with low molecular weight and aromaticity, as well as more degradation of humic-like materials (C3 component). The highest GLM explaining 89% of the variables, including significant variables (p < 0.05) such as microbial activity, water temperature, and water conductivity, was observed for GRSP characteristics. Therefore, changes in eroded soil GRSP quality can serve as an indicator for improving watershed management and thus protecting aquatic ecosystems.
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Affiliation(s)
- Xueyan Sui
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210046, China
| | - Zhipeng Wu
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210046, China.
| | - Chen Lin
- Key Laboratory of Watershed Geographic Sciences, Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Shenglu Zhou
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210046, China.
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31
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Raeke J, Lechtenfeld OJ, Tittel J, Oosterwoud MR, Bornmann K, Reemtsma T. Linking the mobilization of dissolved organic matter in catchments and its removal in drinking water treatment to its molecular characteristics. WATER RESEARCH 2017; 113:149-159. [PMID: 28213336 DOI: 10.1016/j.watres.2017.01.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/12/2016] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
Drinking water reservoirs in the Northern Hemisphere are largely affected by the decadal-long increase in riverine dissolved organic carbon (DOC) concentrations. The removal of DOC in drinking water treatment is costly and predictions are needed to link DOC removal efficiency to its mobilization in catchments, both of which are determined by the molecular composition. To study the effect of hydrological events and land use on the molecular characteristics of dissolved organic matter (DOM), 36 samples from three different catchment areas in the German low mountain ranges, with DOC concentrations ranging from 3 to 32 mg L-1, were examined. Additionally, nine pairs of samples from downstream drinking water reservoirs were analyzed before and after flocculation. The molecular composition and the age of DOM were analyzed using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and radiocarbon (14C) analysis. At elevated discharge in a forested catchment comparatively younger, more oxygenated and unsaturated molecules of higher molecular weight were preferentially mobilized, likely linked to the reductive mobilization of iron. DOM with highly similar molecular characteristics (O/C ratio > 0.5, m/z > 500) could also be efficiently removed through flocculation in drinking water treatment. The proportion of DOM removed through flocculation ranged between 43% and 73% of DOC and was highest at elevated discharge. In catchment areas with a higher percentage of grassland and agriculture a higher proportion of DOM molecules containing sulfur and nitrogen was detected, which in turn could be less efficiently flocculated. Altogether, it was shown that DOM that is released during large hydrological events can be efficiently flocculated again, suggesting a reversal of similar chemical mechanisms in both processes. Since the occurrence of heavy rainfall events is predicted to increase in the future, event-driven mobilization of DOC may continue to challenge drinking water production.
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Affiliation(s)
- Julia Raeke
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Oliver J Lechtenfeld
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany; Helmholtz Centre for Environmental Research - UFZ, ProVIS - Centre for Chemical Microscopy, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Jörg Tittel
- Helmholtz Centre for Environmental Research - UFZ, Department of Lake Research, Brückstrasse 3a, 39114 Magdeburg, Germany
| | - Marieke R Oosterwoud
- Helmholtz Centre for Environmental Research - UFZ, Department of Hydrogeology, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Katrin Bornmann
- TZW: DVGW Water Technology Center, Wasserwerkstrasse 2, 01326 Dresden, Germany
| | - Thorsten Reemtsma
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany.
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32
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Spatiotemporal Characterization of Chromophoric Dissolved Organic Matter (CDOM) and CDOM-DOC Relationships for Highly Polluted Rivers. WATER 2016. [DOI: 10.3390/w8090399] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Osburn CL, Handsel LT, Peierls BL, Paerl HW. Predicting Sources of Dissolved Organic Nitrogen to an Estuary from an Agro-Urban Coastal Watershed. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8473-8484. [PMID: 27404466 DOI: 10.1021/acs.est.6b00053] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Dissolved organic nitrogen (DON) is the nitrogen (N)-containing component of dissolved organic matter (DOM) and in aquatic ecosystems is part of the biologically reactive nitrogen pool that can degrade water quality in N-sensitive waters. Unlike inorganic N (nitrate and ammonium) DON is comprised of many different molecules of variable reactivity. Few methods exist to track the sources of DON in watersheds. In this study, DOM excitation-emission matrix (EEM) fluorescence of eight discrete DON sources was measured and modeled with parallel factor analysis (PARAFAC) and the resulting model ("FluorMod") was fit to 516 EEMs measured in surface waters from the main stem of the Neuse River and its tributaries, located in eastern North Carolina. PARAFAC components were positively correlated to DON concentration. Principle components analysis (PCA) was used to confirm separation of the eight sources and model validation was achieved by measurement of source samples not included in the model development with an error of <10%. Application of FluorMod to surface waters of streams within the Neuse River Basin showed that while >70% of DON was attributed to natural sources, nonpoint sources, such as soil and poultry litter leachates and street runoff, accounted for the remaining 30%. This result was consistent with changes in land use from urbanized Raleigh metropolitan area to the largely agricultural Southeastern coastal plain. Overall, the predicted fraction of nonpoint DON sources was consistent with previous reports of increased organic N inputs in this river basin, which are suspected of impacting the water quality of its estuary.
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Affiliation(s)
- Christopher L Osburn
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University , Raleigh, North Carolina 27695 United States
| | - Lauren T Handsel
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University , Raleigh, North Carolina 27695 United States
| | - Benjamin L Peierls
- Institute of Marine Sciences, University of North Carolina at Chapel Hill , Morehead City, North Carolina 28557 United States
| | - Hans W Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill , Morehead City, North Carolina 28557 United States
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Gücker B, Silva RCS, Graeber D, Monteiro JAF, Boëchat IG. Urbanization and agriculture increase exports and differentially alter elemental stoichiometry of dissolved organic matter (DOM) from tropical catchments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 550:785-792. [PMID: 26849342 DOI: 10.1016/j.scitotenv.2016.01.158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/24/2016] [Accepted: 01/24/2016] [Indexed: 06/05/2023]
Abstract
Many tropical biomes are threatened by rapid land-use change, but its catchment-wide biogeochemical effects are poorly understood. The few previous studies on DOM in tropical catchments suggest that deforestation and subsequent land use increase stream water dissolved organic carbon (DOC) concentrations, but consistent effects on DOM elemental stoichiometry have not yet been reported. Here, we studied stream water DOC concentrations, catchment DOC exports, and DOM elemental stoichiometry in 20 tropical catchments at the Cerrado-Atlantic rainforest transition, dominated by natural vegetation, pasture, intensive agriculture, and urban land cover. Streams draining pasture could be distinguished from those draining natural catchments by their lower DOC concentrations, with lower DOM C:N and C:P ratios. Catchments with intensive agriculture had higher DOC exports and lower DOM C:P ratios than natural catchments. Finally, with the highest DOC concentrations and exports, as well as the highest DOM C:P and N:P ratios, but the lowest C:N ratios among all land-use types, urbanized catchments had the strongest effects on catchment DOM. Thus, urbanization may have alleviated N limitation of heterotrophic DOM decomposition, but increased P limitation. Land use-especially urbanization-also affected the seasonality of catchment biogeochemistry. While natural catchments exhibited high DOC exports and concentrations, with high DOM C:P ratios in the rainy season only, urbanized catchments had high values in these variables throughout the year. Our results suggest that urbanization and pastoral land use exerted the strongest impacts on DOM biogeochemistry in the investigated tropical catchments and should thus be important targets for management and mitigation efforts.
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Affiliation(s)
- Björn Gücker
- Applied Limnology Laboratory, Federal University of São João del-Rei, São João del-Rei, Brazil.
| | - Ricky C S Silva
- Applied Limnology Laboratory, Federal University of São João del-Rei, São João del-Rei, Brazil
| | | | - José A F Monteiro
- Applied Limnology Laboratory, Federal University of São João del-Rei, São João del-Rei, Brazil
| | - Iola G Boëchat
- Applied Limnology Laboratory, Federal University of São João del-Rei, São João del-Rei, Brazil
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Graeber D, Boëchat IG, Encina-Montoya F, Esse C, Gelbrecht J, Goyenola G, Gücker B, Heinz M, Kronvang B, Meerhoff M, Nimptsch J, Pusch MT, Silva RCS, von Schiller D, Zwirnmann E. Global effects of agriculture on fluvial dissolved organic matter. Sci Rep 2015; 5:16328. [PMID: 26541809 PMCID: PMC4635380 DOI: 10.1038/srep16328] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/13/2015] [Indexed: 11/09/2022] Open
Abstract
Agricultural land covers approximately 40% of Earth's land surface and affects hydromorphological, biogeochemical and ecological characteristics of fluvial networks. In the northern temperate region, agriculture also strongly affects the amount and molecular composition of dissolved organic matter (DOM), which constitutes the main vector of carbon transport from soils to fluvial networks and to the sea, and is involved in a large variety of biogeochemical processes. Here, we provide first evidence about the wider occurrence of agricultural impacts on the concentration and composition of fluvial DOM across climate zones of the northern and southern hemispheres. Both extensive and intensive farming altered fluvial DOM towards a more microbial and less plant-derived composition. Moreover, intensive farming significantly increased dissolved organic nitrogen (DON) concentrations. The DOM composition change and DON concentration increase differed among climate zones and could be related to the intensity of current and historical nitrogen fertilizer use. As a result of agriculture intensification, increased DON concentrations and a more microbial-like DOM composition likely will enhance the reactivity of catchment DOM emissions, thereby fuelling the biogeochemical processing in fluvial networks, and resulting in higher ecosystem productivity and CO2 outgassing.
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Affiliation(s)
| | - Iola G Boëchat
- Department of Geosciences, Federal University of São João del-Rei, Brazil
| | - Francisco Encina-Montoya
- Faculty of Natural Resources, Environmental Science Nucleus, Catholic University of Temuco, Chile
| | - Carlos Esse
- Faculty of Natural Resources, Environmental Science Nucleus, Catholic University of Temuco, Chile
| | - Jörg Gelbrecht
- Department of Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany
| | - Guillermo Goyenola
- Department of Theoretical and Applied Ecology, CURE - Faculty of Sciences, Universidad de la República, Uruguay
| | - Björn Gücker
- Department of Geosciences, Federal University of São João del-Rei, Brazil
| | - Marlen Heinz
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany
| | | | - Mariana Meerhoff
- Department of Bioscience, Aarhus University, Denmark.,Department of Theoretical and Applied Ecology, CURE - Faculty of Sciences, Universidad de la República, Uruguay
| | - Jorge Nimptsch
- Instituto de Ciencias Marinas y Limnologicas, Facultad de Ciencias, Universidad Austral de Chile, Edificio Emilio Pugin, Campus Isla Teja, Valdivia, Chile
| | - Martin T Pusch
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany
| | - Ricky C S Silva
- Department of Natural Sciences, Federal University of São João del-Rei, Brazil
| | - Daniel von Schiller
- Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country, Spain
| | - Elke Zwirnmann
- Department of Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany
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