Upland soils are important sinks for atmospheric methane (CH4), a process essentially driven by methanotrophic bacteria. Soil CH4 uptake often depends on land use, with afforestation generally increasing the soil CH4 sink. However, the mechanisms driving these changes are not well understood to date. We measured soil CH4 and N2O fluxes along an afforestation chronosequence with Norway spruce (Picea abies L.) established on an extensively grazed subalpine pasture. Our experimental design included forest stands with ages ranging from 25 to >120\uffc2\uffa0years and included a factorial cattle urine addition treatment to test for the sensitivity of soil CH4 uptake to N application. Mean CH4 uptake significantly increased with stand age on all sampling dates. In contrast, CH4 oxidation by sieved soils incubated in the laboratory did not show a similar age dependency. Soil CH4 uptake was unrelated to soil N status (but cattle urine additions stimulated N2O emission). Our data indicated that soil CH4 uptake in older forest stands was driven by reduced soil water content, which resulted in a facilitated diffusion of atmospheric CH4 into soils. The lower soil moisture likely resulted from increased interception and/or evapotranspiration in the older forest stands. This mechanism contrasts alternative explanations focusing on nitrogen dynamics or the composition of methanotrophic communities, although these factors also might be at play. Our findings further imply that the current dramatic increase in forested area increases CH4 uptake in alpine regions.
", "keywords": ["2300 General Environmental Science", "2. Zero hunger", "10127 Institute of Evolutionary Biology and Environmental Studies", "13. Climate action", "2304 Environmental Chemistry", "570 Life sciences; biology", "590 Animals (Zoology)", "2306 Global and Planetary Change", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "15. Life on land", "2303 Ecology", "6. Clean water"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2012.02798.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1365-2486.2012.02798.x", "name": "item", "description": "10.1111/j.1365-2486.2012.02798.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2012.02798.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-09-07T00:00:00Z"}}, {"id": "10.1111/gcb.12666", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:19:24Z", "type": "Journal Article", "created": "2014-06-21", "title": "Interactive Effects Of Elevated Co2 And Nitrogen Deposition On Fatty Acid Molecular And Isotope Composition Of Above- And Belowground Tree Biomass And Forest Soil Fractions", "description": "AbstractAtmospheric carbon dioxide (CO2) and reactive nitrogen (N) concentrations have been increasing due to human activities and impact the global carbon (C) cycle by affecting plant photosynthesis and decomposition processes in soil. Large amounts of C are stored in plants and soils, but the mechanisms behind the stabilization of plant\uffe2\uff80\uff90 and microbial\uffe2\uff80\uff90derived organic matter (OM) in soils are still under debate and it is not clear how N deposition affects soil OM dynamics. Here, we studied the effects of 4\uffc2\uffa0years of elevated (13C\uffe2\uff80\uff90depleted) CO2 and N deposition in forest ecosystems established in open\uffe2\uff80\uff90top chambers on composition and turnover of fatty acids (FAs) in plants and soils. FAs served as biomarkers for plant\uffe2\uff80\uff90 and microbial\uffe2\uff80\uff90derived OM in soil density fractions. We analyzed above\uffe2\uff80\uff90 and belowground plant biomass of beech and spruce trees as well as soil density fractions for the total organic C and FA molecular and isotope (\uffce\uffb413C) composition. FAs did not accumulate relative to total organic C in fine mineral fractions, showing that FAs are not effectively stabilized by association with soil minerals. The \uffce\uffb413C values of FAs in plant biomass increased under high N deposition. However, the N effect was only apparent under elevated CO2 suggesting a N limitation of the system. In soil fractions, only isotope compositions of short\uffe2\uff80\uff90chain FAs (C16+18) were affected. Fractions of \uffe2\uff80\uff98new\uffe2\uff80\uff99 (experimental\uffe2\uff80\uff90derived) FAs were calculated using isotope depletion in elevated CO2 plots and decreased from free light to fine mineral fractions. \uffe2\uff80\uff98New\uffe2\uff80\uff99 FAs were higher in short\uffe2\uff80\uff90chain compared to long\uffe2\uff80\uff90chain FAs (C20\uffe2\uff88\uff9230), indicating a faster turnover of short\uffe2\uff80\uff90chain compared to long\uffe2\uff80\uff90chain FAs. Increased N deposition did not significantly affect the quantity of \uffe2\uff80\uff98new\uffe2\uff80\uff99 FAs in soil fractions, but showed a tendency of increased amounts of \uffe2\uff80\uff98old\uffe2\uff80\uff99 (pre\uffe2\uff80\uff90experimental) C suggesting that decomposition of \uffe2\uff80\uff98old\uffe2\uff80\uff99 C is retarded by high N inputs.
", "keywords": ["UFSP13-8 Global Change and Biodiversity", "2306 Global and Planetary Change", "Chemical Fractionation", "Forests", "2300 General Environmental Science", "Soil", "Fagus", "Environmental Chemistry", "Biomass", "Photosynthesis", "Picea", "General Environmental Science", "2. Zero hunger", "Global and Planetary Change", "Analysis of Variance", "Carbon Isotopes", "Ecology", "Atmosphere", "Fatty Acids", "04 agricultural and veterinary sciences", "Carbon Dioxide", "15. Life on land", "Reactive Nitrogen Species", "13. Climate action", "2304 Environmental Chemistry", "570 Life sciences; biology", "0401 agriculture", " forestry", " and fisheries", "2303 Ecology"]}, "links": [{"href": "https://doi.org/10.1111/gcb.12666"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/gcb.12666", "name": "item", "description": "10.1111/gcb.12666", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/gcb.12666"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2014-07-08T00:00:00Z"}}, {"id": "10.1111/gcb.16989", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:19:27Z", "type": "Journal Article", "created": "2023-10-27", "title": "Shifts in soil ammonia\u2010oxidizing community maintain the nitrogen stimulation of nitrification across climatic conditions", "description": "AbstractAnthropogenic nitrogen (N) loading alters soil ammonia\uffe2\uff80\uff90oxidizing archaea (AOA) and bacteria (AOB) abundances, likely leading to substantial changes in soil nitrification. However, the factors and mechanisms determining the responses of soil AOA:AOB and nitrification to N loading are still unclear, making it difficult to predict future changes in soil nitrification. Herein, we synthesize\uffc2\uffa068 field studies around the world to evaluate the impacts of N loading on soil ammonia oxidizers and nitrification. Across a wide range of biotic and abiotic factors, climate is the most important driver of the responses of AOA:AOB to N loading. Climate does not directly affect the N\uffe2\uff80\uff90stimulation of nitrification, but does so via climate\uffe2\uff80\uff90related shifts in AOA:AOB. Specifically, climate modulates the responses of AOA:AOB to N loading by affecting soil pH, N\uffe2\uff80\uff90availability and moisture. AOB play a dominant role in affecting nitrification in dry climates, while the impacts from AOA can exceed AOB in humid climates. Together, these results suggest that climate\uffe2\uff80\uff90related shifts in soil ammonia\uffe2\uff80\uff90oxidizing community maintain the N\uffe2\uff80\uff90stimulation of nitrification, highlighting the importance of microbial community composition in mediating the responses of the soil N cycle to N loading.Anthropogenic nitrogen (N) loading alters soil ammonia\uffe2\uff80\uff90oxidizing archaea (AOA) and bacteria (AOB) abundances, likely leading to substantial changes in soil nitrification. However, the factors and mechanisms determining the responses of soil AOA:AOB and nitrification to N loading are still unclear, making it difficult to predict future changes in soil nitrification. Herein, we synthesize\uffc2\uffa068 field studies around the world to evaluate the impacts of N loading on soil ammonia oxidizers and nitrification. Across a wide range of biotic and abiotic factors, climate is the most important driver of the responses of AOA:AOB to N loading. Climate does not directly affect the N\uffe2\uff80\uff90stimulation of nitrification, but does so via climate\uffe2\uff80\uff90related shifts in AOA:AOB. Specifically, climate modulates the responses of AOA:AOB to N loading by affecting soil pH, N\uffe2\uff80\uff90availability and moisture. AOB play a dominant role in affecting nitrification in dry climates, while the impacts from AOA can exceed AOB in humid climates. Together, these results suggest that climate\uffe2\uff80\uff90related shifts in soil ammonia\uffe2\uff80\uff90oxidizing community maintain the N\uffe2\uff80\uff90stimulation of nitrification, highlighting the importance of microbial community composition in mediating the responses of the soil N cycle to N loading.