Emissions of the trace gas nitrous oxide (N2O) play an important role for the greenhouse effect and stratospheric ozone depletion, but the impacts of climate change on N2O fluxes and the underlying microbial drivers remain unclear. The aim of this study was to determine the effects of sustained climate change on field N2O fluxes and associated microbial enzymatic activities, microbial population abundance and community diversity in an extensively managed, upland grassland. We recorded N2O fluxes, nitrification and denitrification, microbial population size involved in these processes and community structure of nitrite reducers (nirK) in a grassland exposed for 4\uffc2\uffa0years to elevated atmospheric CO2 (+200\uffc2\uffa0ppm), elevated temperature (+3.5\uffc2\uffa0\uffc2\uffb0C) and reduction of summer precipitations (\uffe2\uff88\uff9220%) as part of a long\uffe2\uff80\uff90term, multifactor climate change experiment. Our results showed that both warming and simultaneous application of warming, summer drought and elevated CO2 had a positive effect on N2O fluxes, nitrification, N2O release by denitrification and the population size of N2O reducers and NH4 oxidizers. In situ N2O fluxes showed a stronger correlation with microbial population size under warmed conditions compared with the control site. Specific lineages of nirK denitrifier communities responded significantly to temperature. In addition, nirK community composition showed significant changes in response to drought. Path analysis explained more than 85% of in situ N2O fluxes variance by soil temperature, denitrification activity and specific denitrifying lineages. Overall, our study underlines that climate\uffe2\uff80\uff90induced changes in grassland N2O emissions reflect climate\uffe2\uff80\uff90induced changes in microbial community structure, which in turn modify microbial processes.
", "keywords": ["d\u00e9nitrification", "Biodiversit\u00e9 et Ecologie", "551", "AOB", "diversity", "Biodiversity and Ecology", "nosZ", "[SDV.EE.ECO] Life Sciences [q-bio]/Ecology", " environment/Ecosystems", "nirK", "Milieux et Changements globaux", "2. Zero hunger", "changement climatique", "denitrification", "grasslands", "N2O", "prairie", "04 agricultural and veterinary sciences", "15. Life on land", "nitrification", "6. Clean water", "[SDE.BE] Environmental Sciences/Biodiversity and Ecology", "climate change", "13. Climate action", "[SDV.EE.ECO]Life Sciences [q-bio]/Ecology", "AOB;changement climatique;d\u00e9nitrification;diversit\u00e9;prairie;N2O;nitrification", "0401 agriculture", " forestry", " and fisheries", "[SDE.BE]Environmental Sciences/Biodiversity and Ecology", "environment/Ecosystems"]}, "links": [{"href": "https://hal.science/halsde-00722571/file/Cantarel_gcb12_1.pdf"}, {"href": "https://doi.org/10.1111/j.1365-2486.2012.02692.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.1365-2486.2012.02692.x", "name": "item", "description": "10.1111/j.1365-2486.2012.02692.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2012.02692.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-05-08T00:00:00Z"}}, {"id": "10.1016/j.soilbio.2014.06.024", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:17:06Z", "type": "Journal Article", "created": "2014-07-03", "title": "Identifying Response Groups Of Soil Nitrifiers And Denitrifiers To Grazing And Associated Soil Environmental Drivers In Tibetan Alpine Meadows", "description": "Defining response groups within N-related microbial communities is needed to predict land management effect on soil N dynamics, but information on such response groups and associated environmental drivers is scarce. We investigated the abundance and major populations of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nirS- and nirK-harboring denitrifiers under different grazing managements in Tibetan alpine meadow soils. Grazing increased AOB and AOA abundances up to 42 fold and 3.7 fold, respectively, and increased the percentage of AOB within total ammonia oxidizers from 3.1% to 10.8%. The abundance of nirK-like denitrifiers increased with grazing intensity, while the abundance of nirS-like denitrifiers tended to decrease. However, sub-groups within each of these broad groups of (de)nitrifiers responded differently to grazing. Soil nitrate was the main driver of the abundance of denitrifier subgroups (nirK or nirS) positively responding to grazing, while soil moisture and carbon concentration were the main drivers of the abundance of denitrifier sub-groups negatively responding to grazing. AOB and nirK-harboring denitrifiers thus generally responded more positively to grazing than AOA and nirS-harboring denitrifiers, but significant functional diversity existed within each group. Our approach demonstrates the usefulness of the concept of response groups to better characterize and understand (de)nitrifier response to grazing. (C) 2014 Elsevier Ltd. All rights reserved.", "keywords": ["nirS", "2. Zero hunger", "Soil nitrogen cycling", "[SDV]Life Sciences [q-bio]", "04 agricultural and veterinary sciences", "15. Life on land", "630", "AOA", "AOB", "Community structure", "[SDV] Life Sciences [q-bio]", "Abundance", "nirK", "amoA", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://doi.org/10.1016/j.soilbio.2014.06.024"}, {"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.2014.06.024", "name": "item", "description": "10.1016/j.soilbio.2014.06.024", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.soilbio.2014.06.024"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2014-10-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2011.02470.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:18:55Z", "type": "Journal Article", "created": "2011-07-06", "title": "Can Differences In Microbial Abundances Help Explain Enhanced N2o Emissions In A Permanent Grassland Under Elevated Atmospheric Co2?", "description": "AbstractLong\uffe2\uff80\uff90term effects of elevated atmospheric CO2 on the ammonia\uffe2\uff80\uff90oxidizing and denitrifying bacteria in a grassland soil were investigated to test whether a shift in abundance of these N\uffe2\uff80\uff90cycling microorganisms was responsible for enhanced N2O emissions under elevated atmospheric CO2. Soil samples (7.5\uffc2\uffa0cm increments to 45\uffc2\uffa0cm depth) were collected in 2008 from the University of Giessen Free Air Carbon dioxide Enrichment (GiFACE), a permanent grassland exposed to moderately elevated atmospheric CO2 (+20%) since 1998. GiFACE plots lay on a soil moisture gradient because of gradually changing depth to the underlying water table and labeled as the DRY block (furthest from water table), MED block (intermediate to water table), and WET block (nearest to water table). Mean N2O emissions measured since 1998 have been significantly higher under elevated CO2. This study sought to identify microbial and biochemical parameters that might explain higher N2O emissions under elevated CO2. Soil biochemical parameters [extractable organic carbon (EOC), dissolved organic nitrogen (DON), NH4+, NO3\uffe2\uff88\uff92], and abundances of genes encoding the key enzymes involved in ammonia oxidation (amoA) and denitrification (nirK, nirS, nosZ) depended more on soil depth and block (underlying soil moisture gradient) than on elevated CO2. Ammonia oxidation and denitrification gene abundances, relative abundances (ratios) of nirS to nirK, of nosZ to both nirS and to nirK, and of the measured soil biochemical properties DON and NO3\uffe2\uff88\uff92 tended to be lower in elevated CO2 plots as compared with ambient plots in the MED and WET blocks while the DRY block exhibited an opposite trend. High N2O emissions under elevated CO2 in the MED and WET blocks correlated with lower nosZ to nirK ratios, suggesting that increased N2O emissions under elevated CO2 might be caused by a higher proportion of N2O\uffe2\uff80\uff90producing rather than N2O consuming (N2 producing) denitrifiers.
", "keywords": ["nirS", "2. Zero hunger", "N2O emissions", "denitrification", "[SDE.MCG]Environmental Sciences/Global Changes", "04 agricultural and veterinary sciences", "15. Life on land", "AOA", "6. Clean water", "AOB", "soil", "Enrichissement en gaz carbonique", "[SDE.MCG] Environmental Sciences/Global Changes", "Concentration \u00e9lev\u00e9e en CO2", "nosZ", "FACE", "13. Climate action", "ammonia oxidation", "nirK", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2011.02470.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.1365-2486.2011.02470.x", "name": "item", "description": "10.1111/j.1365-2486.2011.02470.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2011.02470.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2011-07-10T00:00:00Z"}}, {"id": "10.4067/s0718-58392015000500015", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:21:21Z", "type": "Journal Article", "created": "2015-10-09", "title": "Effect Of Chemical Fertilization And Green Manure On The Abundance And Community Structure Of Ammonia Oxidizers In A Paddy Soil", "description": "Ammonia oxidization is a critical step in the soil N cycle and can be affected by the fertilization regimes. Chinese milk-vetch (Astragalus sinicus L., MV) is a major green manure of rice (Oryza sativa L.) fields in southern China, which is recommended as an important agronomic practice to improve soil fertility. Soil chemical properties, abundance and community structures of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in a MV-rice rotation field under different fertilization regimes were investigated. The field experiment included six treatments: control, without MV and chemical fertilizer (CK); 100% chemical fertilizer (NPK); 18 000 kg MV ha-1 plus 100% chemical fertilizer (NPKM1); 18 000 kg MV ha-1 plus 40% chemical fertilizer (NPKM2); 18 000 kg MV ha-1 alone (MV); and 18 000 kg MV ha-1 plus 40% chemical fertilizer plus straw (NPKMS). Results showed that NPKMS treatment could improve the soil fertility greatly although the application of 60% chemical fertilizer. The abundance of AOB only in the MV treatment had significant difference with the control; AOA were more abundant than AOB in all corresponding treatments. The NPKMS treatment had the highest AOA abundance (1.19 x 108 amoA gene copies g-1) and the lowest abundance was recorded in the CK treatment (3.21 x 107 amoA gene copies g-1). The abundance of AOA was significantly positively related to total N, available N, NH4+-N, and NO3--N. The community structure of AOA exhibited little variation among different fertilization regimes, whereas the community structure of AOB was highly responsive. Phylogenetic analysis showed that all AOB sequences were affiliated with Nitrosospira or Nitrosomonas and all AOA denaturing gradient gel electrophoresis (DGGE) bands belonged to the soil and sediment lineage. These findings could be fundamental to improve our understanding of AOB and AOA in the N cycle in the paddy soil.", "keywords": ["0301 basic medicine", "2. Zero hunger", "0303 health sciences", "03 medical and health sciences", "Astragalus sinicus", "soil chemical properties", "Abundance", "ammonia-oxidizing bacteria (AOB)", "Chinese milk vetch", "community structure", "15. Life on land", "ammonia-oxidizing archaea (AOA)", "6. Clean water"], "contacts": [{"organization": "Fang, Yu, Yan, Zhi-Lei, Chen, Ji-Chen, Wang, Fei, Wang, Ming-Kuang, Lin, Xin-Jian,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.4067/s0718-58392015000500015"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Chilean%20journal%20of%20agricultural%20research", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.4067/s0718-58392015000500015", "name": "item", "description": "10.4067/s0718-58392015000500015", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.4067/s0718-58392015000500015"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2015-12-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=AOB&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=AOB&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=AOB&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=AOB&offset=4", "hreflang": "en-US"}], "numberMatched": 4, "numberReturned": 4, "distributedFeatures": [], "timeStamp": "2026-07-26T14:00:26.273672Z"}