Effects of summer extreme events on grassland soil CO2 efflux in a contest of future climate change

Autor: Augusti, Angela, Landais, D, Benot, Marie-Lise, Hasibeder, R, Bahn, M, Roumet, Catherine, Roy, J, Soussana, Jean-François, Cochard, Catherine
Přispěvatelé: National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Centre National de la Recherche Scientifique (CNRS), Unité de recherche sur l'Ecosystème Prairial (UREP), Institut National de la Recherche Agronomique (INRA), Leopold Franzens Universität Innsbruck - University of Innsbruck, Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Collège de Direction (CODIR), Max-Planck-Institut. Jena, DEU., Consiglio Nazionale delle Ricerche (CNR), UR 0874 Unité de recherche sur l'Ecosystème Prairial, Institut National de la Recherche Agronomique (INRA)-Unité de recherche sur l'Ecosystème Prairial (UREP)-Ecologie des Forêts, Prairies et milieux Aquatiques (EFPA), University of Innsbruck, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD [France-Sud])
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Open Science Conference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: Impacts and Feedbacks Across Scales, Seefeld, Austria, 2-5 aprile, 2013
info:cnr-pdr/source/autori:Angela Augusti, Damien Landais, Marie-Lise Benot, Roland Hasibeder, Michael Bahn, Catherine Roumet, Jacques Roy, Jean-François Soussana, Catherine Picon-Cochard/congresso_nome:Open Science Conference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: Impacts and Feedbacks Across Scales/congresso_luogo:Seefeld, Austria/congresso_data:2-5 aprile, 2013/anno:2013/pagina_da:/pagina_a:/intervallo_pagine
OpenScienceConference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: Impacts and Feedbacks Across Scales
OpenScienceConference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: Impacts and Feedbacks Across Scales, 2013, Seefeld, Austria. 1 p., 2013
OpenScienceConference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: Impacts and Feedbacks Across Scales, Seefeld, AUT
Popis: Climate models forecast, for the coming future, an increase in frequency of extremes events, such as heat waves and severe droughts. In grassland ecosystem most of the carbon is stored in the soil and its flux toward the soil is the second larger among all ecosystems. Soil CO2 efflux derives from two main components, autotrophic respiration being associated with root and rhizosphere respiration and heterotrophic respiration associated with the turnover of soil organic matter by microorganisms. The aim of this work was to evaluate the vulnerability of a grassland ecosystem under summer extreme events in a context of future climate and the possible mitigation effect of increased CO2. In particular, we studied the extreme event effects on soil efflux and on its autotrophic and heterotrophic components. Grassland monoliths were exposed, from 2010, to air temperature and precipitation expected for the period 2040-2060. Since March 2011 a CO2 enrichment was applied and during summer a heat wave and drought stress were applied too. Total efflux was strongly reduced during the extreme event treatments both at ambient and at elevated CO2; this reduction was due mainly to the autotrophic component since the treatments seemed to have a mild effect on heterotrophic respiration. The reduction in total flux was well described by the reduction in soil moisture. Soil efflux strongly recovered from extreme events, indeed, total respiration showed a faster recovery compared to heterotrophic respiration. This was associated to a sustained recovery in root respiration, root growth rate and root dry matter content. Instead, root decomposition in extreme treatments, in the same period, was still lower than control. This behavior agrees with preliminary data on daily ecosystem carbon uptake showing a stronger recovery after rewetting. In view of these results, the interactions between extreme events and elevated CO2 will be discussed.
Databáze: OpenAIRE
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