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.soilbio.2018.08.014", "type": "Feature", "geometry": null, "properties": {"license": "Closed Access", "updated": "2026-07-27T16:17:29Z", "type": "Journal Article", "created": "2018-09-19", "title": "Environmental drivers of the geographical distribution of methanotrophs: Insights from a national survey", "description": "Closed AccessM.D-B. acknowledges support from the Marie Sklodowska-Curie Actions of the Horizon 2020 Framework Programme H2020-MSCA-IF-2016 under REA grant agreement n\u00b0 702057. The B.K.S. team was supported by Australian Research Council grants (DP 170104634).", "keywords": ["PmoA", "2. Zero hunger", "0301 basic medicine", "0303 health sciences", "Spatial modelling", "spatial ecology", "niche (ecology)", "15. Life on land", "333", "03 medical and health sciences", "methanotrophs", "Methanotrophs", "Mapping", "Biogeography", "Niche partitioning", "13. Climate action", "XXXXXX - Unknown", "11. Sustainability", "mapping", "biogeography"]}, "links": [{"href": "https://doi.org/10.1016/j.soilbio.2018.08.014"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Soil%20Biology%20and%20Biochemistry", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.soilbio.2018.08.014", "name": "item", "description": "10.1016/j.soilbio.2018.08.014", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.soilbio.2018.08.014"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-12-01T00:00:00Z"}}, {"id": "10.1111/geb.12928", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-07-27T16:19:29Z", "type": "Journal Article", "created": "2019-05-14", "title": "Global drivers of methane oxidation and denitrifying gene distribution in drylands", "description": "AbstractAimMicroorganisms carrying pmoA and nosZ genes are major drivers of methane and nitrous oxide fluxes from soils. However, most studies on these organisms have been conducted in mesic ecosystems; therefore, little is known about the factors driving their distribution in drylands, the largest biome on Earth. We conducted a global survey to evaluate the role of climate\uffe2\uff80\uff90 and soil\uffe2\uff80\uff90related variables as predictors of the richness, abundance and community structure of bacteria carrying pmoA and nosZ genes.
LocationEighty dryland ecosystems distributed worldwide.
Time periodFrom February 2006 to December 2011.
Major taxa studiedMethanotrophic (carrying the pmoA gene) and denitrifiying (carrying the nosZ gene) bacteria.
MethodsWe used data from a field survey and structural equation modelling to evaluate the direct and indirect effects of climatic (aridity, rainfall seasonality and mean annual temperature) and soil (organic carbon, pH and texture) variables on the total abundance, richness and community structure of microorganisms carrying pmoA and nosZ genes.
ResultsTaxa related to Methylococcus capsulatus or Methylocapsa sp., often associated with mesic environments, were common in global drylands. The abundance and richness of methanotrophs were not associated with climate or soil properties. However, mean annual temperature, rainfall seasonality, organic C, pH and sand content were highly correlated with their community structure. Aridity and soil variables, such as sand content and pH, were correlated with the abundance, community structure and richness of the nosZ bacterial community.
Main conclusionsOur study provides new insights into the drivers of the abundance, richness and community structure of soil microorganisms carrying pmoA and nosZ genes in drylands worldwide. We highlight how ongoing climate change will alter the structure of soil microorganisms, which might affect the net CH4 exchange and will probably reduce the capacity of dryland soils to carry out the final step of denitrification, favouring net N2O emissions.Microorganisms carrying pmoA and nosZ genes are major drivers of methane and nitrous oxide fluxes from soils. However, most studies on these organisms have been conducted in mesic ecosystems; therefore, little is known about the factors driving their distribution in drylands, the largest biome on Earth. We conducted a global survey to evaluate the role of climate\uffe2\uff80\uff90 and soil\uffe2\uff80\uff90related variables as predictors of the richness, abundance and community structure of bacteria carrying pmoA and nosZ genes.
LocationEighty dryland ecosystems distributed worldwide.
Time periodFrom February 2006 to December 2011.
Major taxa studiedMethanotrophic (carrying the pmoA gene) and denitrifiying (carrying the nosZ gene) bacteria.
MethodsWe used data from a field survey and structural equation modelling to evaluate the direct and indirect effects of climatic (aridity, rainfall seasonality and mean annual temperature) and soil (organic carbon, pH and texture) variables on the total abundance, richness and community structure of microorganisms carrying pmoA and nosZ genes.
ResultsTaxa related to Methylococcus capsulatus or Methylocapsa sp., often associated with mesic environments, were common in global drylands. The abundance and richness of methanotrophs were not associated with climate or soil properties. However, mean annual temperature, rainfall seasonality, organic C, pH and sand content were highly correlated with their community structure. Aridity and soil variables, such as sand content and pH, were correlated with the abundance, community structure and richness of the nosZ bacterial community.
Main conclusionsOur study provides new insights into the drivers of the abundance, richness and community structure of soil microorganisms carrying pmoA and nosZ genes in drylands worldwide. We highlight how ongoing climate change will alter the structure of soil microorganisms, which might affect the net CH4 exchange and will probably reduce the capacity of dryland soils to carry out the final step of denitrification, favouring net N2O emissions.Microorganisms carrying pmoA and nosZ genes are major drivers of methane and nitrous oxide fluxes from soils. However, most studies on these organisms have been conducted in mesic ecosystems; therefore, little is known about the factors driving their distribution in drylands, the largest biome on Earth. We conducted a global survey to evaluate the role of climate\uffe2\uff80\uff90 and soil\uffe2\uff80\uff90related variables as predictors of the richness, abundance and community structure of bacteria carrying pmoA and nosZ genes.
LocationEighty dryland ecosystems distributed worldwide.
Time periodFrom February 2006 to December 2011.
Major taxa studiedMethanotrophic (carrying the pmoA gene) and denitrifiying (carrying the nosZ gene) bacteria.
MethodsWe used data from a field survey and structural equation modelling to evaluate the direct and indirect effects of climatic (aridity, rainfall seasonality and mean annual temperature) and soil (organic carbon, pH and texture) variables on the total abundance, richness and community structure of microorganisms carrying pmoA and nosZ genes.
ResultsTaxa related to Methylococcus capsulatus or Methylocapsa sp., often associated with mesic environments, were common in global drylands. The abundance and richness of methanotrophs were not associated with climate or soil properties. However, mean annual temperature, rainfall seasonality, organic C, pH and sand content were highly correlated with their community structure. Aridity and soil variables, such as sand content and pH, were correlated with the abundance, community structure and richness of the nosZ bacterial community.
Main conclusionsOur study provides new insights into the drivers of the abundance, richness and community structure of soil microorganisms carrying pmoA and nosZ genes in drylands worldwide. We highlight how ongoing climate change will alter the structure of soil microorganisms, which might affect the net CH4 exchange and will probably reduce the capacity of dryland soils to carry out the final step of denitrification, favouring net N2O emissions.