1. Seasonality alters drivers of soil enzyme activity in subalpine grassland soil undergoing climate change
- Author
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Jean-Jacques Brun, Alexandre Buttler, Bjorn J. M. Robroek, Konstantin Gavazov, Sébastien De Danieli, Robert I. Griffiths, Lauric Cécillon, Robert T. E. Mills, Vincent E. J. Jassey, Thomas Spiegelberger, Jeremy Puissant, Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Ecole Polytechnique Fédérale de Lausanne (EPFL), Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire des systèmes écologiques (ECOS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Unité Ecosystèmes Montagnards, Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, and Swiss Federal Institute for Forest, Snow and Avalanche Research WSL
- Subjects
temperature sensitivity ,soil organic matter fractions ,dissolved organic-matter ,010504 meteorology & atmospheric sciences ,growing-season ,Soil Science ,Climate change ,01 natural sciences ,Microbiology ,climate manipulation ,structural equation models ,current knowledge ,land-use ,path analysis ,Organic matter ,Ecosystem ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,2. Zero hunger ,chemistry.chemical_classification ,decomposition ,Soil organic matter ,Global warming ,04 agricultural and veterinary sciences ,Soil carbon ,Mineralization (soil science) ,15. Life on land ,SUISSE ,carbon pools ,chemistry ,Agronomy ,Agriculture and Soil Science ,microbial community structure ,13. Climate action ,Soil water ,soil microbial communities ,040103 agronomy & agriculture ,co2 ,0401 agriculture, forestry, and fisheries ,Environmental science ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,recalcitrance ,feedbacks - Abstract
International audience; In mountain ecosystems with marked seasonality, climate change can affect various processes in soils, potentially modifying long-term key soil services via change in soil organic carbon (C) storage. Based on a four-year soil transplantation experiment in Swiss subalpine grasslands, we investigated how imposed climate warming and reduced precipitation modified the drivers of soil carbon enzyme potential activities across winter and summer seasons. Specifically, we used structural equation models (SEMs) to identify biotic (microbial community structure, abundance and activity) and abiotic (quantity and quality of organic matter resources) drivers of soil C-enzymes (hydrolase and oxidase) in two seasons under two different climate scenarios. We found contrasting impacts of the climate manipulation on the drivers of C-enzymes between winter and summer. In winter, no direct effect of climate manipulation (reduced rainfall and warming) on enzyme activity was observed. Yet, climate indirectly down-regulated enzyme activity through a decrease in the availability of water extractable organic carbon (WEOC) labile resources. During summer, reduced soil moisture -induced by the climate manipulation- directly reduced soil microbial biomass, which led to a decrease in C-enzyme activity. In general, across both seasons, neither microbial community structure, nor organic matter quality were strong determinants of enzymatic activity. In particular organic matter recalcitrance (aromaticity) was not found as a general driver of either hydrolase or oxidase C-enzyme potential activities, though we did observe higher C-enzyme activities led to an increase of particulate organic matter recalcitrance in the summer season. Overall, our results highlight the seasonality of climate change effects on soil organic matter enzymatic decomposition, providing a comprehensive picture of seasonal potential cause and effect relationships governing C mineralization in subalpine grassland.
- Published
- 2018
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