Studies on tree CH4 exchange in boreal forests regarding seasonality and role of tree canopies are rare. We aimed to quantify the contribution of boreal trees to the forest CH4 budget during spring leaf-out and to reveal the role of microbes in the CH4 exchange.
MethodsMethane fluxes of downy birch and Norway spruce (Betula pubescens and Picea abies) growing on fen and upland sites were measured together with soil CH4 flux, environmental variables and microbial abundances involved in the CH4 cycle. Tree CH4 fluxes were studied from three stem heights and from shoots.
ResultsThe trees emitted CH4 with higher stem emissions detected from birch and higher shoot emissions from spruce. The stem CH4 emissions from birches at the fen were high (mean 45\uffc2\uffa0\uffc2\uffb5g\uffc2\uffa0m\uffe2\uff88\uff922\uffc2\uffa0h\uffe2\uff88\uff921), decreasing with stem height. Their dynamics followed soil temperature, suggesting the emitted CH4 originated from methanogenic activity, manifested in high mcrA gene copy numbers, in the peat soil. Methanogens were below the quantification limit in the tree tissues. Upscaled tree CH4 emissions accounted for 22% of the total CH4 emissions at the fen.
ConclusionsThe variation in stem CH4 flux between the trees and habitats is high, and the emissions from high-emitting birches increase as the spring proceeds. The lack of detection of methanogens or methanotrophs in the aboveground plant tissues suggests that these microbes did not have a significant role in the observed tree-derived fluxes. The stem-emitted CH4 from birches at the fen is presumably produced microbially in the soil.
", "keywords": ["0301 basic medicine", "570", "550", "Methanogens", "LIVING TREES", "Trees", "03 medical and health sciences", "Methanotrophs", "METHANE EMISSIONS", "SAP FLOW", "Boreal forest", "Waterlogging", "PRECURSOR", "0303 health sciences", "BIOMASS EQUATIONS", "NORWAY SPRUCE", "Forestry", "Methane fux", "15. Life on land", "Environmental sciences", "METHANOTROPHS", "13. Climate action", "RADIATION", "Methane flux", "VEGETATION", "COMMUNITIES"]}, "links": [{"href": "https://link.springer.com/content/pdf/10.1007/s11104-022-05447-9.pdf"}, {"href": "https://doi.org/10.1007/s11104-022-05447-9"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-022-05447-9", "name": "item", "description": "10.1007/s11104-022-05447-9", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-022-05447-9"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-05-24T00:00:00Z"}}, {"id": "10.1016/j.scitotenv.2020.138080", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-07-27T16:17:13Z", "type": "Journal Article", "created": "2020-03-19", "title": "Stimulation of methane production from benzoate with addition of carbon materials", "description": "Huge amounts of wastewater that contain aromatic compounds such as benzene and phenols are discharged worldwide. Benzoate is a typical intermediate in the anaerobic transformation of those aromatic compounds. In this study, electrically conductive carbon-based materials of granulated activated carbon (GAC), multiwalled carbon nanotubes (MwCNTs), and graphite were evaluated for the ability to promote the benzoate degradation. The results showed that 82\u201393% of the electrons were recovered in CH4 production from benzoate. The carbon materials stimulated benzoate degradation in the sequence of GAC (5 g/L) N MwCNTs (1 g/L) ~ Graphite (0.1 g/L) N Control. Acetate was the only detected intermediate in the process of benzoate degradation. Taxonomic analyses revealed that benzoate was degraded by Syntrophus to acetate and H2, which were subsequently converted to methane by Methanosarcina (both acetoclastic methanogens and hydrogenotrophic methanogens) and Methanoculleus (hydrogenotrophic methanogens), and direct interspecies electron transfer (DIET) of Desulfovibrio and Methanosarcina. Thus, these results suggest a method to effectively enhance the removal of aromatic compounds and methane recovery", "keywords": ["0301 basic medicine", "0303 health sciences", "Nanotubes", " Carbon", "Direct interspecies electron transfer", "Carbon materials", "Benzoates", "6. Clean water", "Benzoate", "Electron Transport", "03 medical and health sciences", "13. Climate action", "Methanosarcina", "Acetoclastic methanogens", "Syntrophus", "Anaerobiosis", "Hydrogenotrophic methanogens", "Methane"]}, "links": [{"href": "https://doi.org/10.1016/j.scitotenv.2020.138080"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.scitotenv.2020.138080", "name": "item", "description": "10.1016/j.scitotenv.2020.138080", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.scitotenv.2020.138080"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-01T00:00:00Z"}}, {"id": "10.1111/j.1574-6941.2007.00394.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:19:44Z", "type": "Journal Article", "created": "2007-10-19", "title": "Quantitation And Diversity Analysis Of Ruminal Methanogenic Populations In Response To The Antimethanogenic Compound Bromochloromethane", "description": "Methyl coenzyme-M reductase A (mcrA) clone libraries were generated from microbial DNA extracted from the rumen of cattle fed a roughage diet with and without supplementation of the antimethanogenic compound bromochloromethane. Bromochloromethane reduced total methane emissions by c. 30%, with a resultant increase in propionate and branched chain fatty acids. The mcrA clone libraries revealed that Methanobrevibacter spp. were the dominant species identified. A decrease in the incidence of Methanobrevibacter spp. from the clone library generated from bromochloromethane treatment was observed. In addition, a more diverse methanogenic population with representatives from Methanococcales, Methanomicrobiales and Methanosacinales orders was observed for the bromochloromethane library. Sequence data generated from these libraries aided in the design of an mcrA-targeted quantitative PCR (qPCR) assay. The reduction in methane production by bromochloromethane was associated with an average decrease of 34% in the number of methanogenic Archaea when monitored with this qPCR assay. Dissociation curve analysis of mcrA amplicons showed a clear difference in melting temperatures for Methanobrevibacter spp. (80-82 degrees C) and all other methanongens (84-86 degrees C). A decrease in the intensity of the Methanobrevibacter spp. specific peak and an increase for the other peak in the bromochloromethane-treated animals corresponded with the changes within the clone libraries.", "keywords": ["Male", "0301 basic medicine", "Rumen", "Bromochloromethane", "Methanogens", "Molecular Sequence Data", "Euryarchaeota", "Methanobrevibacter", "Polymerase Chain Reaction", "630", "03 medical and health sciences", "2402 Applied Microbiology and Biotechnology", "Animals", "Methyl coenzyme-M reductase", "Phylogeny", "Gene Library", "2. Zero hunger", "0303 health sciences", "Hydrocarbons", " Halogenated", "2404 Microbiology", "Sequence Analysis", " DNA", "mcrA", "qPCR", "DNA", " Archaeal", "Cattle", "Oxidoreductases", "2303 Ecology", "Methane"]}, "links": [{"href": "https://doi.org/10.1111/j.1574-6941.2007.00394.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/FEMS%20Microbiology%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1574-6941.2007.00394.x", "name": "item", "description": "10.1111/j.1574-6941.2007.00394.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1574-6941.2007.00394.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2007-12-01T00:00:00Z"}}, {"id": "10.3389/fvets.2021.706592", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-07-27T16:21:40Z", "type": "Journal Article", "created": "2021-09-07", "title": "Presence of adult companion goats favors the rumen microbial and functional development in artificially reared kids", "description": "Newborn dairy ruminants are usually separated from their dams after birth and fed on milk replacer. This lack of contact with adult animals may hinder the rumen microbiological and physiological development. This study evaluates the effects of rearing newborn goat kids in contact with adult companions on the rumen development. Thirty-two newborn goat kids were randomly allocated to two experimental groups which were reared either in the absence (CTL) or in the presence of non-lactating adult goats (CMP) and weaned at 7 weeks of age. Blood and rumen samples were taken at 5, 7, and 9 weeks of age to evaluate blood metabolites and rumen microbial fermentation. Next-generation sequencing was carried out on rumen samples collected at 7 weeks of age. Results showed that CTL kids lacked rumen protozoa, whereas CMP kids had an abundant and complex protozoal community as well as higher methanogen abundance which positively correlated with the body weight and blood \uffce\uffb2-hydroxybutyrate as indicators of the physiological development. CMP kids also had a more diverse bacterial community (+132 ASVs) and a different structure of the bacterial and methanogen communities than CTL kids. The core rumen bacterial community in CMP animals had 53 more ASVs than that of CTL animals. Furthermore, the number of ASVs shared with the adult companions was over 4-fold higher in CMP kids than in CTL kids. Greater levels of early rumen colonizers Proteobacteria and Spirochaetes were found in CTL kids, while CMP kids had higher levels of Bacteroidetes and other less abundant taxa (Veillonellaceae, Cyanobacteria, and Selenomonas). These findings suggest that the presence of adult companions facilitated the rumen microbial development prior to weaning. This accelerated microbial development had no effect on the animal growth, but CMP animals presented higher rumen pH and butyrate (+45%) and ammonia concentrations than CTL kids, suggesting higher fibrolytic and proteolytic activities. CMP kids also had higher blood \uffce\uffb2-hydroxybutyrate (+79%) and lower blood glucose concentrations (-23%) at weaning, indicating an earlier metabolic development which could favor the transition from pre-ruminant to ruminant after the weaning process. Further research is needed to determine the effects of this intervention in more challenging farm conditions.
", "keywords": ["2. Zero hunger", "0301 basic medicine", "0303 health sciences", "Bacteria", "Methanogens", "rumen colonization", "weaning", "Veterinary medicine", "Weaning", "protozoa", "03 medical and health sciences", "SF600-1100", "Veterinary Science", "methanogens", "Rumen colonization", "Protozoa", "bacteria"]}, "links": [{"href": "https://doi.org/10.3389/fvets.2021.706592"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Veterinary%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/fvets.2021.706592", "name": "item", "description": "10.3389/fvets.2021.706592", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/fvets.2021.706592"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-09-07T00:00:00Z"}}, {"id": "3011642440", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-07-27T16:27:29Z", "type": "Journal Article", "created": "2020-03-19", "title": "Stimulation of methane production from benzoate with addition of carbon materials", "description": "Huge amounts of wastewater that contain aromatic compounds such as benzene and phenols are discharged worldwide. Benzoate is a typical intermediate in the anaerobic transformation of those aromatic compounds. In this study, electrically conductive carbon-based materials of granulated activated carbon (GAC), multiwalled carbon nanotubes (MwCNTs), and graphite were evaluated for the ability to promote the benzoate degradation. The results showed that 82\u201393% of the electrons were recovered in CH4 production from benzoate. The carbon materials stimulated benzoate degradation in the sequence of GAC (5 g/L) N MwCNTs (1 g/L) ~ Graphite (0.1 g/L) N Control. Acetate was the only detected intermediate in the process of benzoate degradation. Taxonomic analyses revealed that benzoate was degraded by Syntrophus to acetate and H2, which were subsequently converted to methane by Methanosarcina (both acetoclastic methanogens and hydrogenotrophic methanogens) and Methanoculleus (hydrogenotrophic methanogens), and direct interspecies electron transfer (DIET) of Desulfovibrio and Methanosarcina. Thus, these results suggest a method to effectively enhance the removal of aromatic compounds and methane recovery", "keywords": ["0301 basic medicine", "0303 health sciences", "Nanotubes", " Carbon", "Direct interspecies electron transfer", "Carbon materials", "Benzoates", "6. Clean water", "Benzoate", "Electron Transport", "03 medical and health sciences", "13. Climate action", "Methanosarcina", "Acetoclastic methanogens", "Syntrophus", "Anaerobiosis", "Hydrogenotrophic methanogens", "Methane"]}, "links": [{"href": "https://doi.org/3011642440"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "3011642440", "name": "item", "description": "3011642440", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/3011642440"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-01T00:00:00Z"}}, {"id": "32220738", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-07-27T16:27:47Z", "type": "Journal Article", "created": "2020-03-19", "title": "Stimulation of methane production from benzoate with addition of carbon materials", "description": "Huge amounts of wastewater that contain aromatic compounds such as benzene and phenols are discharged worldwide. Benzoate is a typical intermediate in the anaerobic transformation of those aromatic compounds. In this study, electrically conductive carbon-based materials of granulated activated carbon (GAC), multiwalled carbon nanotubes (MwCNTs), and graphite were evaluated for the ability to promote the benzoate degradation. The results showed that 82\u201393% of the electrons were recovered in CH4 production from benzoate. The carbon materials stimulated benzoate degradation in the sequence of GAC (5 g/L) N MwCNTs (1 g/L) ~ Graphite (0.1 g/L) N Control. Acetate was the only detected intermediate in the process of benzoate degradation. Taxonomic analyses revealed that benzoate was degraded by Syntrophus to acetate and H2, which were subsequently converted to methane by Methanosarcina (both acetoclastic methanogens and hydrogenotrophic methanogens) and Methanoculleus (hydrogenotrophic methanogens), and direct interspecies electron transfer (DIET) of Desulfovibrio and Methanosarcina. Thus, these results suggest a method to effectively enhance the removal of aromatic compounds and methane recovery", "keywords": ["0301 basic medicine", "0303 health sciences", "Nanotubes", " Carbon", "Direct interspecies electron transfer", "Carbon materials", "Benzoates", "6. Clean water", "Benzoate", "Electron Transport", "03 medical and health sciences", "13. Climate action", "Methanosarcina", "Acetoclastic methanogens", "Syntrophus", "Anaerobiosis", "Hydrogenotrophic methanogens", "Methane"]}, "links": [{"href": "https://doi.org/32220738"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "32220738", "name": "item", "description": "32220738", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/32220738"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Methanogens&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Methanogens&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Methanogens&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Methanogens&offset=6", "hreflang": "en-US"}], "numberMatched": 6, "numberReturned": 6, "distributedFeatures": [], "timeStamp": "2026-07-27T20:55:10.696104Z"}