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Machacova K, Schindler T, Bréchet L, Mander Ü, Grams TEE. Substantial uptake of nitrous oxide (N 2O) by shoots of mature European beech. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173122. [PMID: 38734086 DOI: 10.1016/j.scitotenv.2024.173122] [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: 02/22/2024] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Similar to soils, tree stems emit and consume nitrous oxide (N2O) from the atmosphere. Although tree leaves dominate tree surface area, they have been completely excluded from field N2O flux measurements and therefore their role in forest N2O exchange remains unknown. We explored the contribution of leaf fluxes to forest N2O exchange. We determined the N2O exchange of mature European beech (Fagus sylvatica) stems and shoots (i.e., terminal branches) and of adjacent forest floor, in a typical temperate upland forest in Germany. The beech stems, and particularly the shoots, acted as net N2O sinks (-0.254 ± 0.827 μg N2O m-2 stem area h-1 and -4.54 ± 1.53 μg N2O m-2 leaf area h-1, respectively), while the forest floor was a net source (2.41 ± 1.08 μg N2O m-2 soil area h-1). The unstudied tree shoots were identified as a significant contributor to the net ecosystem N2O exchange. Moreover, we revealed for the first time that tree leaves act as substantial N2O sinks. Although this is the first study of its kind, it is of global importance for the proper design of future flux studies in forest ecosystems worldwide. Our results demonstrate that excluding tree leaves from forest N2O flux measurements can lead to misinterpretation of tree and forest N2O exchange, and thus global forest greenhouse gas flux inventories.
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Affiliation(s)
- Katerina Machacova
- Department of Ecosystem Trace Gas Exchange, Global Change Research Institute of the Czech Academy of Sciences, Belidla 4a, CZ-60300 Brno, Czech Republic.
| | - Thomas Schindler
- Department of Ecosystem Trace Gas Exchange, Global Change Research Institute of the Czech Academy of Sciences, Belidla 4a, CZ-60300 Brno, Czech Republic; Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, 46 Vanemuise, EST-51014 Tartu, Estonia
| | - Laëtitia Bréchet
- INRAE, UMR EcoFoG, CNRS, Cirad, AgroParisTech, Université des Antilles, Université de Guyane, FR-97310 Kourou, France
| | - Ülo Mander
- Department of Ecosystem Trace Gas Exchange, Global Change Research Institute of the Czech Academy of Sciences, Belidla 4a, CZ-60300 Brno, Czech Republic; Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, 46 Vanemuise, EST-51014 Tartu, Estonia
| | - Thorsten E E Grams
- Department of Life Science Systems, School of Life Sciences, Technical University of Munich, Von-Carlowitz-Platz 2, DE-85354 Freising, Germany
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Liao X, Wang Y, Malghani S, Zhu X, Cai W, Qin Z, Wang F. Methane and nitrous oxide emissions and related microbial communities from mangrove stems on Qi'ao Island, Pearl River Estuary in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:170062. [PMID: 38220023 DOI: 10.1016/j.scitotenv.2024.170062] [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: 11/13/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/16/2024]
Abstract
Mangrove forests, crucial carbon-rich ecosystems, are increasingly vulnerable to soil carbon loss and greenhouse gas (GHG) emissions due to human disturbance. However, the contribution of mangrove trees to GHG emissions remains poorly understood. This study monitored CO2, CH4, and N2O fluxes from the stems of two mangrove species, native Kandelia obovata (KO) and exotic Sonneratia apetala (SA), at three heights (0.7 m, 1.2 m, and 1.7 m) during the dry winter period on Qi'ao Island, Pearl River Estuary, China. Heartwood samples were analyzed to identify potential functional groups related to gas fluxes. Our study found that tree stems acted as both sinks and sources for N2O (ranging from -9.49 to 28.35 μg m-2 h-1 for KO and from -6.73 to 28.95 μg m-2 h-1 for SA) and CH4. SA exhibited significantly higher stem CH4 flux (from -26.67 to 97.33 μg m-2 h-1) compared to KO (from -44.13 to 88.0 μg m-2 h-1) (P < 0.05). When upscaled to the community level, both species were net emitters of CH4, contributing approximately 4.68 % (KO) and 0.51 % (SA) to total CH4 emissions. The decrease in stem CH4 flux with increasing height, indicates a soil source. Microbial analysis in the heartwood using the KEGG database indicated aceticlastic methanogenesis as the dominant CH4 pathway. The presence of methanogens, methanotrophs, denitrifiers, and nitrifiers suggests microbial involvement in CH4 and N2O production and consumption. Remarkably, the dominance of Cyanobacteria in the heartwood microbiome (with the relative abundance of 97.5 ± 0.6 % for KO and 99.1 ± 0.2 % for SA) implies roles in carbon and nitrogen fixation for mangroves coping with nitrogen limitation in coastal wetlands, and possibly in CH4 production. Although the present study has limitations in sampling duration and area, it highlights the significant role of tree stems in GHG emissions which is crucial for a holistic evaluation of the global carbon sequestration capability of mangrove ecosystems. Future research should broaden spatial and temporal scales to enhance the accuracy of upscaling tree stem gas fluxes to the mangrove ecosystem level.
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Affiliation(s)
- Xiaolin Liao
- College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Ying Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China
| | - Saadatullah Malghani
- College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Copenhagen, Denmark
| | - Xudong Zhu
- Key Laboratory of the Coastal and Wetland Ecosystems (Ministry of Education), College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian, China; Fujian Key Laboratory of Severe Weather, Fuzhou 350008, Fujian, China
| | - Wenqi Cai
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China
| | - Zhangcai Qin
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China; Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Zhuhai 519082, China
| | - Fan Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China; Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Zhuhai 519082, China; School of Ecology, Sun Yat-sen University, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, Guangdong, China.
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Machacova K, Warlo H, Svobodová K, Agyei T, Uchytilová T, Horáček P, Lang F. Methane emission from stems of European beech (Fagus sylvatica) offsets as much as half of methane oxidation in soil. THE NEW PHYTOLOGIST 2023; 238:584-597. [PMID: 36631959 DOI: 10.1111/nph.18726] [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: 06/15/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Trees are known to be atmospheric methane (CH4 ) emitters. Little is known about seasonal dynamics of tree CH4 fluxes and relationships to environmental conditions. That prevents the correct estimation of net annual tree and forest CH4 exchange. We aimed to explore the contribution of stem emissions to forest CH4 exchange. We determined seasonal CH4 fluxes of mature European beech (Fagus sylvatica) stems and adjacent soil in a typical temperate beech forest of the White Carpathians with high spatial heterogeneity in soil moisture. The beech stems were net annual CH4 sources, whereas the soil was a net CH4 sink. High CH4 emitters showed clear seasonality in their stem CH4 emissions that followed stem CO2 efflux. Elevated CH4 fluxes were detected during the vegetation season. Observed high spatial variability in stem CH4 emissions was neither explicably by soil CH4 exchange nor by CH4 concentrations, water content, or temperature studied in soil profiles near each measured tree. The stem CH4 emissions offset the soil CH4 uptake by up to 46.5% and on average by 13% on stand level. In Central Europe, widely grown beech contributes markedly to seasonal dynamics of ecosystem CH4 exchange. Its contribution should be included into forest greenhouse gas flux inventories.
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Affiliation(s)
- Katerina Machacova
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
| | - Hannes Warlo
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
- Chair of Soil Ecology, Albert-Ludwigs-University, Bertoldstrasse 17, DE-79098, Freiburg, Germany
| | - Kateřina Svobodová
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
| | - Thomas Agyei
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
- Department of Environmental Management, School of Natural Resources, University of Energy and Natural Resources, Box 214, Sunyani, Ghana
| | - Tereza Uchytilová
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
| | - Petr Horáček
- Global Change Research Institute of the Czech Academy of Sciences, 4a Belidla, CZ-60300, Brno, Czech Republic
| | - Friederike Lang
- Chair of Soil Ecology, Albert-Ludwigs-University, Bertoldstrasse 17, DE-79098, Freiburg, Germany
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4
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Mander Ü, Krasnova A, Schindler T, Megonigal JP, Escuer-Gatius J, Espenberg M, Machacova K, Maddison M, Pärn J, Ranniku R, Pihlatie M, Kasak K, Niinemets Ü, Soosaar K. Long-term dynamics of soil, tree stem and ecosystem methane fluxes in a riparian forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151723. [PMID: 34801507 DOI: 10.1016/j.scitotenv.2021.151723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/20/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
The carbon (C) budgets of riparian forests are sensitive to climatic variability. Therefore, riparian forests are hot spots of C cycling in landscapes. Only a limited number of studies on continuous measurements of methane (CH4) fluxes from riparian forests is available. Here, we report continuous high-frequency soil and ecosystem (eddy-covariance; EC) measurements of CH4 fluxes with a quantum cascade laser absorption spectrometer for a 2.5-year period and measurements of CH4 fluxes from tree stems using manual chambers for a 1.5 year period from a temperate riparian Alnus incana forest. The results demonstrate that the riparian forest is a minor net annual sink of CH4 consuming 0.24 kg CH4-C ha-1 y-1. Soil water content is the most important determinant of soil, stem, and EC fluxes, followed by soil temperature. There were significant differences in CH4 fluxes between the wet and dry periods. During the wet period, 83% of CH4 was emitted from the tree stems while the ecosystem-level emission was equal to the sum of soil and stem emissions. During the dry period, CH4 was substantially consumed in the soil whereas stem emissions were very low. A significant difference between the EC fluxes and the sum of soil and stem fluxes during the dry period is most likely caused by emission from the canopy whereas at the ecosystem level the forest was a clear CH4 sink. Our results together with past measurements of CH4 fluxes in other riparian forests suggest that temperate riparian forests can be long-term CH4 sinks.
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Affiliation(s)
- Ülo Mander
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Global Change Research Institute of the Czech Academy of Sciences, Department of Ecosystem Trace Gas Exchange, Belidla 986/4a, 603 00 Brno, Czech Republic.
| | - Alisa Krasnova
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia
| | - Thomas Schindler
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Global Change Research Institute of the Czech Academy of Sciences, Department of Ecosystem Trace Gas Exchange, Belidla 986/4a, 603 00 Brno, Czech Republic
| | - J Patrick Megonigal
- Smithsonian Environmental Institute, 647 Contees Wharf Road Edgewater, MD 21037-0028, USA
| | - Jordi Escuer-Gatius
- Institute of Agricultural & Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia
| | - Mikk Espenberg
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Katerina Machacova
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Global Change Research Institute of the Czech Academy of Sciences, Department of Ecosystem Trace Gas Exchange, Belidla 986/4a, 603 00 Brno, Czech Republic
| | - Martin Maddison
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Jaan Pärn
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Reti Ranniku
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Mari Pihlatie
- Department of Agricultural Sciences, Environmental Soil Sciences, University of Helsinki, Latokartanonkaari 7, 00014 Helsinki, Finland; Institute for Atmospheric and Earth System Research (INAR) / Forest Science, University of Helsinki, Physicum, Kumpula campus, Gustaf Hällströmin katu 2, 00560 Helsinki, Finland; Department of Agricultural Sciences, Viikki Plant Science Centre (ViPS), University of Helsinki, Viikinkaari 2a, 00014 Helsinki, Finland
| | - Kuno Kasak
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
| | - Ülo Niinemets
- Institute of Agricultural & Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia
| | - Kaido Soosaar
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Global Change Research Institute of the Czech Academy of Sciences, Department of Ecosystem Trace Gas Exchange, Belidla 986/4a, 603 00 Brno, Czech Republic
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5
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Abstract
Tree stems play an important role in forest methane (CH4) and nitrous oxide (N2O) flux dynamics. Our paper aimed to determine the unknown diurnal variability of CH4 and N2O exchange in grey alder tree stems. The gas fluxes in tree stems and adjacent soil were measured using manual static and dynamic chamber systems with gas chromatographic and laser-spectroscopic analysis, respectively. The alder trees were predominant emitters of CH4 and N2O; however, N2O emission from stems was negligible. The soil mainly emitted N2O into the atmosphere and was both a source and sink of CH4, depending on environmental conditions. Neither the tree stems nor the riparian forest soil showed significant differences in their CH4 and N2O fluxes between the daytime and nighttime, independently of the exchange rates. In contrast to several previous studies revealing a diurnal variability of greenhouse gas fluxes from tree stems, our investigation did not show any clear daytime–nighttime differences. On the other hand, we found quite clear seasonal dynamics initiated by changing environmental conditions, such as temperature and soil water conditions and tree physiological activity. Our results imply a transport role of tree stems for soil-produced CH4 and N2O rather than the production of these gases in tree tissues, even though this cannot be excluded.
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Jeffrey LC, Maher DT, Tait DR, Reading MJ, Chiri E, Greening C, Johnston SG. Isotopic evidence for axial tree stem methane oxidation within subtropical lowland forests. THE NEW PHYTOLOGIST 2021; 230:2200-2212. [PMID: 33715152 DOI: 10.1111/nph.17343] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
Knowledge regarding mechanisms moderating methane (CH4 ) sink/source behaviour along the soil-tree stem-atmosphere continuum remains incomplete. Here, we applied stable isotope analysis (δ13 C-CH4 ) to gain insights into axial CH4 transport and oxidation in two globally distributed subtropical lowland species (Melaleuca quinquenervia and Casuarina glauca). We found consistent trends in CH4 flux (decreasing with height) and δ13 C-CH4 enrichment (increasing with height) in relation to stem height from ground. The average lower tree stem δ13 C-CH4 (0-40 cm) of Melaleuca and Casuarina (-53.96‰ and -65.89‰) were similar to adjacent flooded soil CH4 ebullition (-52.87‰ and -62.98‰), suggesting that stem CH4 is derived mainly by soil sources. Upper stems (81-200 cm) displayed distinct δ13 C-CH4 enrichment (Melaleuca -44.6‰ and Casuarina -46.5‰, respectively). Coupled 3D-photogrammetry with novel 3D-stem measurements revealed distinct hotspots of CH4 flux and isotopic fractionation on Melaleuca, which were likely due to bark anomalies in which preferential pathways of gas efflux were enhanced. Diel experiments revealed greater δ13 C-CH4 enrichment and higher oxidation rates in the afternoon, compared with the morning. Overall, we estimated that c. 33% of the methane was oxidised between lower and upper stems during axial transport, therefore potentially representing a globally significant, yet previously unaccounted for, methane sink.
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Affiliation(s)
- Luke C Jeffrey
- SCU Geoscience, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
- Faculty of Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Damien T Maher
- SCU Geoscience, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
- Faculty of Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Douglas R Tait
- SCU Geoscience, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
- Faculty of Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Michael J Reading
- SCU Geoscience, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
- Faculty of Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Eleonora Chiri
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Scott G Johnston
- SCU Geoscience, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
- Faculty of Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
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Machacova K, Schindler T, Soosaar K. Fourier transform infrared spectroscopy and interference of volatile organic compounds on measurements of methane (CH 4 ) fluxes at tree stems - a general phenomenon for plant systems? THE NEW PHYTOLOGIST 2021; 230:2100-2104. [PMID: 33998686 PMCID: PMC9291908 DOI: 10.1111/nph.17311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Katerina Machacova
- Department of Ecosystem Trace Gas ExchangeGlobal Change Research Institute of the Czech Academy of Sciences4a BelidlaBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
| | - Thomas Schindler
- Department of Ecosystem Trace Gas ExchangeGlobal Change Research Institute of the Czech Academy of Sciences4a BelidlaBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
| | - Kaido Soosaar
- Department of Ecosystem Trace Gas ExchangeGlobal Change Research Institute of the Czech Academy of Sciences4a BelidlaBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
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Machacova K, Borak L, Agyei T, Schindler T, Soosaar K, Mander Ü, Ah‐Peng C. Trees as net sinks for methane (CH 4 ) and nitrous oxide (N 2 O) in the lowland tropical rain forest on volcanic Réunion Island. THE NEW PHYTOLOGIST 2021; 229:1983-1994. [PMID: 33058184 PMCID: PMC7894294 DOI: 10.1111/nph.17002] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/01/2020] [Indexed: 05/26/2023]
Abstract
Trees are known to emit methane (CH4 ) and nitrous oxide (N2 O), with tropical wetland trees being considerable CH4 sources. Little is known about CH4 and especially N2 O exchange of trees growing in tropical rain forests under nonflooded conditions. We determined CH4 and N2 O exchange of stems of six dominant tree species, cryptogamic stem covers, soils and volcanic surfaces at the start of the rainy season in a 400-yr-old tropical lowland rain forest situated on a basaltic lava flow (Réunion Island). We aimed to understand the unknown role in greenhouse gas fluxes of these atypical tropical rain forests on basaltic lava flows. The stems studied were net sinks for atmospheric CH4 and N2 O, as were cryptogams, which seemed to be co-responsible for the stem uptake. In contrast with more commonly studied rain forests, the soil and previously unexplored volcanic surfaces consumed CH4 . Their N2 O fluxes were negligible. Greenhouse gas uptake potential by trees and cryptogams constitutes a novel and unique finding, thus showing that plants can serve not only as emitters, but also as consumers of CH4 and N2 O. The volcanic tropical lowland rain forest appears to be an important CH4 sink, as well as a possible N2 O sink.
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Affiliation(s)
- Katerina Machacova
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
| | - Libor Borak
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
| | - Thomas Agyei
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
| | - Thomas Schindler
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
| | - Kaido Soosaar
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
| | - Ülo Mander
- Global Change Research Institute of the Czech Academy of SciencesBelidla 986/4aBrnoCZ‐60300Czech Republic
- Department of GeographyInstitute of Ecology & Earth SciencesUniversity of Tartu46 VanemuiseTartuEST‐51014Estonia
| | - Claudine Ah‐Peng
- UMR PVBMTUniversité de La Réunion7 chemin de l’IRATSaint‐Pierre, La RéunionF‐97410France
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Schindler T, Mander Ü, Machacova K, Espenberg M, Krasnov D, Escuer-Gatius J, Veber G, Pärn J, Soosaar K. Short-term flooding increases CH 4 and N 2O emissions from trees in a riparian forest soil-stem continuum. Sci Rep 2020; 10:3204. [PMID: 32081925 PMCID: PMC7035275 DOI: 10.1038/s41598-020-60058-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/04/2020] [Indexed: 11/09/2022] Open
Abstract
One of the characteristics of global climate change is the increase in extreme climate events, e.g., droughts and floods. Forest adaptation strategies to extreme climate events are the key to predict ecosystem responses to global change. Severe floods alter the hydrological regime of an ecosystem which influences biochemical processes that control greenhouse gas fluxes. We conducted a flooding experiment in a mature grey alder (Alnus incana (L.) Moench) forest to understand flux dynamics in the soil-tree-atmosphere continuum related to ecosystem N2O and CH4 turn-over. The gas exchange was determined at adjacent soil-tree-pairs: stem fluxes were measured in vertical profiles using manual static chambers and gas chromatography; soil fluxes were measured with automated chambers connected to a gas analyser. The tree stems and soil surface were net sources of N2O and CH4 during the flooding. Contrary to N2O, the increase in CH4 fluxes delayed in response to flooding. Stem N2O fluxes were lower although stem CH4 emissions were significantly higher than from soil after the flooding. Stem fluxes decreased with stem height. Our flooding experiment indicated soil water and nitrogen content as the main controlling factors of stem and soil N2O fluxes. The stems contributed up to 88% of CH4 emissions to the stem-soil continuum during the investigated period but soil N2O fluxes dominated (up to 16 times the stem fluxes) during all periods. Conclusively, stem fluxes of CH4 and N2O are essential elements in forest carbon and nitrogen cycles and must be included in relevant models.
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Affiliation(s)
- Thomas Schindler
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia. .,Department of Ecosystem Trace Gas Exchange, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic.
| | - Ülo Mander
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia
| | - Katerina Machacova
- Department of Ecosystem Trace Gas Exchange, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Mikk Espenberg
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia
| | - Dmitrii Krasnov
- Department of Plant Physiology, Estonian University of Life Sciences, Tartu, Estonia
| | | | - Gert Veber
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia
| | - Jaan Pärn
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia
| | - Kaido Soosaar
- Department of Geography, Institute of Ecology & Earth Sciences, University of Tartu, Tartu, Estonia
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Timilsina A, Zhang C, Pandey B, Bizimana F, Dong W, Hu C. Potential Pathway of Nitrous Oxide Formation in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:1177. [PMID: 32849729 PMCID: PMC7412978 DOI: 10.3389/fpls.2020.01177] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/20/2020] [Indexed: 05/12/2023]
Abstract
Plants can produce and emit nitrous oxide (N2O), a potent greenhouse gas, into the atmosphere, and several field-based studies have concluded that this gas is emitted at substantial amounts. However, the exact mechanisms of N2O production in plant cells are unknown. Several studies have hypothesised that plants might act as a medium to transport N2O produced by soil-inhabiting microorganisms. Contrarily, aseptically grown plants and axenic algal cells supplied with nitrate (NO3) are reported to emit N2O, indicating that it is produced inside plant cells by some unknown physiological phenomena. In this study, the possible sites, mechanisms, and enzymes involved in N2O production in plant cells are discussed. Based on the experimental evidence from various studies, we determined that N2O can be produced from nitric oxide (NO) in the mitochondria of plants. NO, a signaling molecule, is produced through oxidative and reductive pathways in eukaryotic cells. During hypoxia and anoxia, NO3 in the cytosol is metabolised to produce nitrite (NO2), which is reduced to form NO via the reductive pathway in the mitochondria. Under low oxygen condition, NO formed in the mitochondria is further reduced to N2O by the reduced form of cytochrome c oxidase (CcO). This pathway is active only when cells experience hypoxia or anoxia, and it may be involved in N2O formation in plants and soil-dwelling animals, as reported previously by several studies. NO can be toxic at a high concentration. Therefore, the reduction of NO to N2O in the mitochondria might protect the integrity of the mitochondria, and thus, protect the cell from the toxicity of NO accumulation under hypoxia and anoxia. As NO3 is a major source of nitrogen for plants and all plants may experience hypoxic and anoxic conditions owing to soil environmental factors, a significant global biogenic source of N2O may be its formation in plants via the proposed pathway.
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Affiliation(s)
- Arbindra Timilsina
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
- University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Arbindra Timilsina, ; Chunsheng Hu,
| | - Chuang Zhang
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bikram Pandey
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Mountain Ecological Restoration and Bio-resource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Fiston Bizimana
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenxu Dong
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
| | - Chunsheng Hu
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
- University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Arbindra Timilsina, ; Chunsheng Hu,
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Machacova K, Vainio E, Urban O, Pihlatie M. Seasonal dynamics of stem N 2O exchange follow the physiological activity of boreal trees. Nat Commun 2019; 10:4989. [PMID: 31676776 PMCID: PMC6825224 DOI: 10.1038/s41467-019-12976-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/03/2019] [Indexed: 11/28/2022] Open
Abstract
The role of trees in the nitrous oxide (N2O) balance of boreal forests has been neglected despite evidence suggesting their substantial contribution. We measured seasonal changes in N2O fluxes from soil and stems of boreal trees in Finland, showing clear seasonality in stem N2O flux following tree physiological activity, particularly processes of CO2 uptake and release. Stem N2O emissions peak during the vegetation season, decrease rapidly in October, and remain low but significant to the annual totals during winter dormancy. Trees growing on dry soils even turn to consumption of N2O from the atmosphere during dormancy, thereby reducing their overall N2O emissions. At an annual scale, pine, spruce and birch are net N2O sources, with spruce being the strongest emitter. Boreal trees thus markedly contribute to the seasonal dynamics of ecosystem N2O exchange, and their species-specific contribution should be included into forest emission inventories. Forest soil is known to be a source of the greenhouse gas N2O, but the impact of what is planted in that soil has long been overlooked. Here Machacova and colleagues quantify seasonal N2O fluxes from common boreal tree species in Finland, finding that all trees are net sources of this gas.
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Affiliation(s)
- Katerina Machacova
- Global Change Research Institute of the Czech Academy of Sciences, Belidla 4a, CZ-60300, Brno, Czech Republic.
| | - Elisa Vainio
- Environmental Soil Science, Department of Agricultural Sciences, University of Helsinki, P.O.Box 56, FI-00014, Helsinki, Finland.,Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, P.O.Box 27, FI-00014, Helsinki, Finland
| | - Otmar Urban
- Global Change Research Institute of the Czech Academy of Sciences, Belidla 4a, CZ-60300, Brno, Czech Republic
| | - Mari Pihlatie
- Environmental Soil Science, Department of Agricultural Sciences, University of Helsinki, P.O.Box 56, FI-00014, Helsinki, Finland.,Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, P.O.Box 27, FI-00014, Helsinki, Finland.,Viikki Plant Science Centre (ViPS), University of Helsinki, P.O.Box 56, FI-00014, Helsinki, Finland
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Barba J, Poyatos R, Vargas R. Automated measurements of greenhouse gases fluxes from tree stems and soils: magnitudes, patterns and drivers. Sci Rep 2019; 9:4005. [PMID: 30850622 PMCID: PMC6408546 DOI: 10.1038/s41598-019-39663-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 01/29/2019] [Indexed: 11/19/2022] Open
Abstract
Tree stems exchange CO2, CH4 and N2O with the atmosphere but the magnitudes, patterns and drivers of these greenhouse gas (GHG) fluxes remain poorly understood. Our understanding mainly comes from static-manual measurements, which provide limited information on the temporal variability and magnitude of these fluxes. We measured hourly CO2, CH4 and N2O fluxes at two stem heights and adjacent soils within an upland temperate forest. We analyzed diurnal and seasonal variability of fluxes and biophysical drivers (i.e., temperature, soil moisture, sap flux). Tree stems were a net source of CO2 (3.80 ± 0.18 µmol m-2 s-1; mean ± 95% CI) and CH4 (0.37 ± 0.18 nmol m-2 s-1), but a sink for N2O (-0.016 ± 0.008 nmol m-2 s-1). Time series analysis showed diurnal temporal correlations between these gases with temperature or sap flux for certain days. CO2 and CH4 showed a clear seasonal pattern explained by temperature, soil water content and sap flux. Relationships between stem, soil fluxes and their drivers suggest that CH4 for stem emissions could be partially produced belowground. High-frequency measurements demonstrate that: a) tree stems exchange GHGs with the atmosphere at multiple time scales; and b) are needed to better estimate fluxes magnitudes and understand underlying mechanisms of GHG stem emissions.
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Affiliation(s)
- Josep Barba
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, 19716, USA
| | - Rafael Poyatos
- CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
| | - Rodrigo Vargas
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, 19716, USA.
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