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Xu X, Jin Q, Liu H, Ma J, Peng Y, Yang Y, Deng Y, Zhou C, Li W, Zuo X, Zhou Y, Wang G. Eutrophication driven macrophyte-derived organic matter decomposition to methane emission relates to co-metabolism effect in freshwater sediments. ENVIRONMENTAL RESEARCH 2024; 260:119624. [PMID: 39038772 DOI: 10.1016/j.envres.2024.119624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/08/2024] [Accepted: 07/14/2024] [Indexed: 07/24/2024]
Abstract
Lakes and wetlands play pivotal roles in global organic matter storage, receiving significant inputs of organic material. However, the co-metabolic processes governing the decomposition of these organic materials and their impact on greenhouse gas emissions remain inadequately understood. This study aims to assess the effects of mixed decomposition involving macrophytes and cyanobacteria on carbon emissions. A series of microcosms was established to investigate the decomposition of macrophyte residues and algae over a period of 216 days. A two-component kinetic model was utilized to estimate methane (CH4) production rates. Gas isotope technology was employed to discern the contributions of CH4 produced by macrophyte residues or algae. Quantitative PCR and analysis of 16S rRNA gene amplicons were employed to assess changes in functional genes and microbial communities. There were significant differences in the cumulative carbon release from the decomposition of different plant types due to the addition of carbon sources. After adding algae, the cumulative emission of CH4 increased significantly. The δ13C-CH4 partitioning indicated that CH4 originated exclusively from the fresh organic carbon of macrophyte residues, while it shifted to algae source after adding algae. The synergistic effect of the mixed decomposition on the CH4 emissions was greater than the sum of the individual decompositions. The microbial community richness was higher in the single plant residue treatment compared to the mixed treatment with algae addition, while microbial evenness in the sediment increased steadily in each treatment. Our findings emphasize the pronounced co-metabolic effect observed during the mixed decomposition of macrophytes and cyanobacteria.
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Affiliation(s)
- Xiaoguang Xu
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Qiu Jin
- Nanjing Hydraulic Research Institute, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing, 210029, China
| | - Huazu Liu
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China; Department of Ecological Sciences and Engineering, Chongqing University, Chongqing, 400044, China
| | - Jie Ma
- Ministry of Ecology and Environment, Nanjing Institute of Environment Sciences, Nanjing, 210042, China
| | - Yu Peng
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Yuxuan Yang
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Yang Deng
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Chuanqiao Zhou
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Wei Li
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400044, China; National Centre for International Research of Low-carbon and Green Buildings, Ministry of Science & Technology, Chongqing University, Chongqing, 400044, China; Chongqing Field Observation Station for River and Lake Ecosystems, Chongqing University, Chongqing, 400044, China; Department of Ecological Sciences and Engineering, Chongqing University, Chongqing, 400044, China.
| | - Xiaojun Zuo
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
| | - Yiwen Zhou
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China.
| | - Guoxiang Wang
- School of Environment, Nanjing Normal University, Nanjing, 210008, China
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Colina M, Meerhoff M, Cabrera-Lamanna L, Kosten S. Experimental warming promotes CO 2 uptake but hinders carbon incorporation toward higher trophic levels in cyanobacteria-dominated freshwater communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 920:171029. [PMID: 38367721 DOI: 10.1016/j.scitotenv.2024.171029] [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: 11/16/2023] [Revised: 01/26/2024] [Accepted: 02/14/2024] [Indexed: 02/19/2024]
Abstract
Shallow freshwaters can exchange large amounts of carbon dioxide (CO2) with the atmosphere and also store significant quantities of carbon (C) in their sediments. Current warming and eutrophication pressures might alter the role of shallow freshwater ecosystems in the C cycle. Although eutrophication has been widely associated to an increase in total phytoplankton biomass and particularly of cyanobacteria, it is still poorly understood how warming may affect ecosystem metabolism under contrasting phytoplankton community composition. We studied the effects of experimental warming on CO2 fluxes and C allocation on two contrasting natural phytoplankton communities: chlorophytes-dominated versus cyanobacteria-dominated, both with a similar zooplankton community with a potentially high grazing capacity (i.e., standardized density of large-bodied cladocerans). The microcosms were subject to two different constant temperatures (control and +4 °C, i.e., 19.5 vs 23.5 °C) and we ensured no nutrient nor light limitation. CO2 uptake increased with warming in both communities, being the strongest in the cyanobacteria-dominated communities. However, only a comparatively minor share of the fixed C translated into increased phytoplankton (Chl-a), and particularly a negligible share translated into zooplankton biomass. Most C was either dissolved in the water (DIC) or sedimented, the latter being potentially available for mineralization into DIC and CO2, or methane (CH4) when anoxic conditions prevail. Our results suggest that C uptake increases with warming particularly when cyanobacteria dominate, however, due to the low efficiency in transfer through the trophic web the final fate of the fixed C may be substantially different in the long run.
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Affiliation(s)
- Maite Colina
- Departamento de Ecología y Gestión Ambiental, Centro Universitario de la Región Este, Universidad de la República, Maldonado, Uruguay; Department of Ecology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, the Netherlands.
| | - Mariana Meerhoff
- Departamento de Ecología y Gestión Ambiental, Centro Universitario de la Región Este, Universidad de la República, Maldonado, Uruguay; Department of Ecoscience, Aarhus University, Aarhus, Denmark
| | - Lucía Cabrera-Lamanna
- Departamento de Ecología y Gestión Ambiental, Centro Universitario de la Región Este, Universidad de la República, Maldonado, Uruguay; Department of Ecology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, the Netherlands
| | - Sarian Kosten
- Department of Ecology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, the Netherlands
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3
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Bauduin T, Gypens N, Borges AV. Seasonal and spatial variations of greenhouse gas (CO 2, CH 4 and N 2O) emissions from urban ponds in Brussels. WATER RESEARCH 2024; 253:121257. [PMID: 38340702 DOI: 10.1016/j.watres.2024.121257] [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: 08/10/2023] [Revised: 01/23/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
Freshwaters have been recognized as important sources of greenhouse gases (GHG) to the atmosphere. However, urban ponds have received little attention even though their number is increasing due to expanding urbanisation globally. Ponds are frequently associated to urban green spaces that provide several ecosystemic services such as cooling local climate, regulating the water cycle, and acting as small carbon sinks This study aims to identify and understand the processes producing GHGs (CO2, CH4, and N2O) in the urban ponds of the temperate European city of Brussels in Belgium. 22 relatively small ponds (0.1-4.6 ha) surrounded by contrasted landscape (strictly urban, bordered by cropland or by forest), were sampled during four seasons in 2021-2022. The mean ± standard deviation was 3,667 ± 2,904 ppm for the partial pressure of CO2 (pCO2), 2,833 ± 4,178 nmol L-1 for CH4, and 273 ± 662% for N2O saturation level (%N2O). Relationships of GHGs with oxygen and water temperature suggest that biological processes controlled pCO2, CH4 concentration and%N2O. However, pCO2 was also controlled by external inputs as indicated by the higher values of pCO2 in the smaller ponds, more subject to external inputs than larger ones. The opposite was observed for CH4 concentration that was higher in larger ponds, closer to the forest in the city periphery, and with higher macrophyte cover. N2O concentrations, as well as dissolved inorganic nitrogen, were higher closer to the city center, where atmospheric nitrogen deposition was potentially higher. The total GHG emissions from the Brussels ponds were estimated to 1kT CO2-eq per year and were equivalent to the carbon sink of urban green spaces.
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Affiliation(s)
- T Bauduin
- Ecology of Aquatic Systems, Free University of Brussels, Belgium; Chemical Oceanography Unit, University of Liège, Belgium.
| | - N Gypens
- Ecology of Aquatic Systems, Free University of Brussels, Belgium
| | - A V Borges
- Chemical Oceanography Unit, University of Liège, Belgium
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Zhu J, Li Y, Huang M, Xu D, Zhang Y, Zhou Q, Wu Z, Wang C. Restoration effects of submerged macrophytes on methane production and oxidation potential of lake sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161218. [PMID: 36584953 DOI: 10.1016/j.scitotenv.2022.161218] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The restoration of submerged macrophytes is an important step in lake ecosystem restoration, during which artificially assisted measures have been widely used for macrophyte recolonization. Compared with natural restoration, the impact of artificially assisted methods on methane (CH4) production and oxidation of lake sediments remains unclear. Therefore, after the restoration of submerged macrophytes in some parts of West Lake (Hangzhou, China), sediment samples from West Lake were collected according to restoration methods and plant coverage. The CH4 production potential, oxidation potential, and microbial community structure in the sediment were discussed through whole-lake sample analysis and resampling verification from typical lake areas. From the analysis of the whole lake, the average daily CH4 production potential (ADP) of artificially restored lake areas (0.12 μg g-1 d-1) was significantly lower than that of the naturally restored lake areas (0.52 μg g-1 d-1). From the resampling analysis of typical lake areas, the ADP of naturally restored lake areas was 1.8 times that of artificially restored lake areas (P < 0.01). Although there was no significant difference in the CH4 oxidation potential between the two restoration methods, the presence of submerged macrophytes significantly increased the abundance of the dominant methanotroph Methylocaldum in the sediment, and the rate of increase in the abundance of the dominant methanotroph Methylosinus was significantly higher in artificially assisted restoration than in natural restoration. This study revealed that the artificially assisted restoration of submerged macrophytes reduced the potential for CH4 production and increased the abundance of dominant methanotrophs in the lake sediment, which would be beneficial for the reduction of CH4 emissions during lake ecological restoration and environmental management.
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Affiliation(s)
- Jianglong Zhu
- Faculty of Resources and Environmental Science, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan 430062, China; Hubei Key Laboratory of Regional Development and Environmental Response, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan 430062, China
| | - Yahua Li
- China University of Geosciences, No. 388 Lumo Road, Hongshan District, Wuhan 430074, China
| | - Minghui Huang
- China University of Geosciences, No. 388 Lumo Road, Hongshan District, Wuhan 430074, China
| | - Dong Xu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China
| | - Yi Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China
| | - Qiaohong Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China
| | - Zhenbin Wu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China
| | - Chuan Wang
- Faculty of Resources and Environmental Science, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan 430062, China; Hubei Key Laboratory of Regional Development and Environmental Response, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan 430062, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China.
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5
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Nijman TPA, Lemmens M, Lurling M, Kosten S, Welte C, Veraart AJ. Phosphorus control and dredging decrease methane emissions from shallow lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157584. [PMID: 35882339 DOI: 10.1016/j.scitotenv.2022.157584] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/17/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Freshwater ecosystems are an important source of the greenhouse gas methane (CH4), and their emissions are expected to increase due to eutrophication. Two commonly applied management techniques to reduce eutrophication are the addition of phosphate-binding lanthanum modified bentonite (LMB, trademark Phoslock©) and dredging, but their effect on CH4 emissions is still poorly understood. Here, this study researched how LMB and dredging affected CH4 emissions using a full-factorial mesocosm design monitored for 18 months. The effect was tested by measuring diffusive and ebullitive CH4 fluxes, plant community composition, methanogen and methanotroph activity and community composition, and a range of physicochemical water and sediment variables. LMB addition decreased total CH4 emissions, while dredging showed a trend towards decreasing CH4 emissions. Total CH4 emissions in all mesocosms were much higher in the summer of the second year, likely because of higher algal decomposition and organic matter availability. First, LMB addition lowered CH4 emissions by decreasing P-availability, which reduced coverage of the floating fern Azolla filiculoides, and thereby prevented anoxia and decreased surface water NH4+ concentrations, lowering CH4 production rates. Second, dredging decreased CH4 emissions in the first summer, possibly it removed the methanogenic community, and in the second year by preventing autumn and winter die-off of the rooted macrophyte Potamogeton cripsus. Finally, methanogen community composition was related to surface water NH4+ and O2, and porewater total phosphorus, while methanotroph community composition was related to organic matter content. To conclude, LMB addition and dredging not only improve water quality, but also decrease CH4 emissions, mitigating climate change.
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Affiliation(s)
- Thomas P A Nijman
- Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
| | - Maxime Lemmens
- Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Miquel Lurling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, the Netherlands
| | - Sarian Kosten
- Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Cornelia Welte
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Annelies J Veraart
- Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
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6
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Thiemer K, Schneider SC, Demars BOL. Mechanical removal of macrophytes in freshwater ecosystems: Implications for ecosystem structure and function. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 782:146671. [PMID: 33838383 DOI: 10.1016/j.scitotenv.2021.146671] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/02/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Macrophytes are generally considered a nuisance when they interfere with human activities. To combat perceived nuisance, macrophytes are removed, and considerable resources are spent every year worldwide on this practice. Macrophyte removal can, however, have severe negative impacts on ecosystem structure and functioning and interfere with management goals of healthy freshwater ecosystems. Here, we reviewed the existing literature on mechanical macrophyte removal and summarised current information from 98 studies on short- and long-term consequences for ecosystem structure and functioning. In general, the majority of studies were conducted in rivers and streams and evaluated short-term effects of removal on single ecosystem properties. Moreover, most studies did not address the interrelationships between ecosystem properties and the underlying mechanisms. Contrasting effects of removal on ecosystem structure and function were found and these discrepancies were highly dependent on the context of each study, making meaningful quantitative comparisons across studies very difficult. We illustrated how a Bayesian network (BN) approach can be used to assess the implications of macrophyte removal on interrelated ecosystem properties across a wide range of environmental conditions. The BN approach could also help engage a conversation with stakeholders on the management of freshwater ecosystems.
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Affiliation(s)
- Kirstine Thiemer
- Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo, Norway; Faculty of Environmental Sciences and Nature Conservation, Norwegian University of Life Sciences, P.O. Box 5003, 1430 Ås, Norway.
| | - Susanne C Schneider
- Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo, Norway; Faculty of Environmental Sciences and Nature Conservation, Norwegian University of Life Sciences, P.O. Box 5003, 1430 Ås, Norway
| | - Benoît O L Demars
- Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo, Norway
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Bartosiewicz M, Maranger R, Przytulska A, Laurion I. Effects of phytoplankton blooms on fluxes and emissions of greenhouse gases in a eutrophic lake. WATER RESEARCH 2021; 196:116985. [PMID: 33735621 DOI: 10.1016/j.watres.2021.116985] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Lakes are important sources of greenhouse gases (GHGs) to the atmosphere. Factors controlling CO2, CH4 and N2O fluxes include eutrophication and warming, but the integrated influence of climate-warming-driven stratification, oxygen loss and resultant changes in bloom characteristics on GHGs are not well understood. Here we assessed the influence of contrasting meteorological conditions on stratification and phytoplankton bloom composition in a eutrophic lake, and tested for associated changes in GHGs inventories in both the shallow and deep waters, over three seasons (2010-2012). Atmospheric heatwaves had one of the most dramatic effects on GHGs. Indeed, cyanobacterial blooms that developed in response to heatwave events in 2012 enhanced both sedimentary CH4 concentrations (reaching up to 1mM) and emissions to the atmosphere (up to 8 mmol m-2 d-1). That summer, CH4 contributed 52% of the integrated warming potential of GHGs produced in the lake (in CO2 equivalents) as compared to between 34 and 39% in years without cyanobacterial blooms. High CH4 accumulation and subsequent emission in 2012 were preceded by CO2 and N2O consumption and under-saturation at the lake surface (uptakes at -30 mmol m-2 d-1 and -1.6 µmol m-2 d-1, respectively). Fall overturn presented a large efflux of N2O and CH4, particularly from the littoral zone after the cyanobacterial bloom. We provide evidence that, despite cooling observed at depth during hot summers, CH4 emissions increased via stronger stratification and surface warming, resulting in enhanced cyanobacterial biomass deposition and intensified bottom water anoxia. Our results, supported by recent literature reports, suggests a novel interplay between climate change effects on lake hydrodynamics that impacts both bloom characteristics and GHGs production in shallow eutrophic lakes. Given global trends of warming and enrichment, these interactive effects should be considered to more accurately predict the future global role of lakes in GHG emissions.
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Affiliation(s)
- Maciej Bartosiewicz
- Department of Environmental Sciences, University of Basel, Basel, Switzerland; Groupe de recherche interuniversitaire en limnologie (GRIL); Centre Eau Terre Environnement, Institut national de la recherche scientifique, 490 de la Couronne, Québec, Canada
| | - Roxane Maranger
- Groupe de recherche interuniversitaire en limnologie (GRIL); Département des Sciences Biologiques, Université de Montréal, C.P. 6128 succ. Centre-ville, Montréal, Canada
| | - Anna Przytulska
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Isabelle Laurion
- Groupe de recherche interuniversitaire en limnologie (GRIL); Centre Eau Terre Environnement, Institut national de la recherche scientifique, 490 de la Couronne, Québec, Canada
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Zhu D, Wu N, Bhattarai N, Oli KP, Chen H, Rawat GS, Rashid I, Dhakal M, Joshi S, Tian J, Zhu Q, Chaudhary S, Tshering K. Methane emissions respond to soil temperature in convergent patterns but divergent sensitivities across wetlands along altitude. GLOBAL CHANGE BIOLOGY 2021; 27:941-955. [PMID: 33222345 DOI: 10.1111/gcb.15454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/08/2020] [Indexed: 06/11/2023]
Abstract
Among the global coordinated patterns in soil temperature and methane emission from wetlands, a declining trend of optimal soil temperature for methane emissions from low to high latitudes has been witnessed, while the corresponding trend along the altitudinal gradient has not yet been investigated. We therefore selected two natural wetlands located at contrasting climatic zones from foothill and mountainside of Nepal Himalayas, to test: (1) whether the optimal temperature for methane emissions decreases from low to high altitude, and (2) whether there is a difference in temperature sensitivity of methane emissions from those wetlands. We found significant spatial and temporal variation of methane emissions between the two wetlands and seasons. Soil temperature was the dominant driver for seasonal variation in methane emissions from both wetlands, though its effect was perplexed by the level of standing water, aquatic plants, and dissolved organic carbon, particularly in the deep water area. When integrative comparison was conducted by adding the existing data from wetlands of diverse altitudes, and the latitude-for-altitude effect was taken into account, we found the baseline soil temperatures decrease whilst the altitude rises with respect to a rapid increase in methane emission from all wetlands, however, remarkably higher sensitivity of methane emissions to soil temperature (apparent Q10 ) was found in mid-altitude wetland. We provide the first evidence of an apparent decline in optimal temperature for methane emissions with increasing elevation. These findings suggest a convergent pattern of methane emissions with respect to seasonal temperature shifts from wetlands along altitudinal gradient, while a divergent pattern in temperature sensitivities exhibits a single peak in mid-altitude.
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Affiliation(s)
- Dan Zhu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Zoige Wetland Ecosystem Research Station, Chinese Academy of Sciences, Hongyuan, China
- Key Laboratory of Mountain Ecological Restoration and Bio-resources Utilization, Chinese Academy of Sciences, Chengdu, China
| | - Ning Wu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Nabin Bhattarai
- International Centre for Integrated Mountain Development, Kathmandu, Nepal
| | | | - Huai Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Zoige Wetland Ecosystem Research Station, Chinese Academy of Sciences, Hongyuan, China
- Key Laboratory of Mountain Ecological Restoration and Bio-resources Utilization, Chinese Academy of Sciences, Chengdu, China
| | - Gopal Singh Rawat
- Faculty of Wildlife Sciences, Wildlife Institute of India, Dehradun, India
| | - Irfan Rashid
- Department of Botany, University of Kashmir, Srinagar, India
| | - Maheshwar Dhakal
- Ministry of Forests and Environment, Government of Nepal, Kathmandu, Nepal
| | - Srijana Joshi
- International Centre for Integrated Mountain Development, Kathmandu, Nepal
| | - Jianqing Tian
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Qiu'an Zhu
- College of Hydrology and Water Resources, Hohai University, Nanjing, China
| | - Sunita Chaudhary
- International Centre for Integrated Mountain Development, Kathmandu, Nepal
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Mei D, Ni M, Liang X, Hou L, Wang F, He C. Filamentous green algae Spirogyra regulates methane emissions from eutrophic rivers. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:3660-3671. [PMID: 32929674 DOI: 10.1007/s11356-020-10754-8] [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: 05/22/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
Excessive growth of filamentous green algae in rivers has attracted much attention due to their functional importance to primary production and carbon cycling. However, comprehensive knowledge of how filamentous green algae affect carbon cycling, especially the CH4 emissions from river ecosystems, remains limited. In this study, incubation experiments were conducted to examine the factors regulating CH4 emissions from a eutrophic river with dense growth of filamentous green algae Spirogyra through combinations of biogeochemical, molecular biological, and stable carbon isotope analyses. Results showed that although water dissolved oxygen (DO) in the algae+sediment (A+S) incubation groups increased up to 19 mg L-1, average CH4 flux of the groups was 13.09 μmol m-2 day-1, nearly up to two times higher than that from sediments without algae (S groups). The significant increase of sediment CH4 oxidation potential and methanotroph abundances identified the enhancing sediment CH4 oxidation during Spirogyra bloom. However, the increased water CH4 concentration was consistent with depleted water [Formula: see text] and decreased apparent fractionation factor (αapp), suggesting the important contribution of Spirogyra to the oxic water CH4 production. It can thus be concluded that high DO concentration during the algal bloom promoted the CH4 consumption by enhancing sediment CH4 oxidation, while algal-linked oxic water CH4 production as a major component of water CH4 promoted the CH4 emissions from the river. Our study highlights the regulation of Spirogyra in aquatic CH4 fluxes and will help to estimate accurately CH4 emissions from eutrophic rivers with dense blooms of filamentous green algae. Graphical abstract.
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Affiliation(s)
- Dan Mei
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Ming Ni
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Xia Liang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200244, China.
| | - Lijun Hou
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200244, China
| | - Feifei Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Chiquan He
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
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