A test of the hierarchical model of litter decomposition

• Published in: Nature Ecology & Evolution
• Main Authors: Bradford, Mark A., Veen, G. F. Ciska, Bonis, Anne, Bradford, Ella M., Classen, Aimee T., Cornelissen, J. Hans C., Crowther, Thomas W., de Long, Jonathan R., Freschet, Gregoire T., Kardol, Paul, Manrubia-Freixa, Marta, Maynard, Daniel S., Newman, Gregory S., Logtestijn, Richard S. P., Viketoft, Maria, Wardle, David A., Wieder, William R., Wood, Stephen A., van Der Putten, Wim H.
• Other Authors: Yale University New Haven, Netherlands Institute of Ecology (NIOO-KNAW), Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Rubenstein School Environment and National Resources, University of Vermont Burlington, Center Macroecology, Evolution and Climate, Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Vrije Universiteit Amsterdam Amsterdam (VU), Institute for Integrative Biology Zürich (IBZ), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), School of Earth and Environmental Sciences Manchester (SEES), University of Manchester Manchester, 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), Swedish University of Agricultural Sciences = Sveriges lantbruksuniversitet (SLU), Yale School Forestry & Environment Studies, Nanyang Technological University Singapour, National Center for Atmospheric Research Boulder (NCAR), The Nature Conservancy, Wageningen University and Research Wageningen (WUR), Research was supported by grants to M.A.B. from the US National Science Foundation (DEB-1457614), The Royal Netherlands Academy of Arts and Sciences (Visiting Professors Programme), and the Netherlands Production Ecology & Resource Conservation Programme for Visiting Scientists. G.F.V. was supported by an NWO-VENI from the Netherlands Organisation for Scientific Research (863.14.013). M.M.-F. and W.H.v.d.P. were supported by a European Research Council grant (ERC-Adv 260-55290), and G.T.F. by grant EC2CO-Multivers.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: Ecosystem ecology; Carbon cycle; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDE]Environmental Sciences; Northern Sweden
• Online Access: https://univ-rennes.hal.science/hal-01659442; https://univ-rennes.hal.science/hal-01659442/document; https://univ-rennes.hal.science/hal-01659442/file/Test%20of%20the%20hierarchical%20model%20of%20litter%20decomposition_accepted.pdf; https://doi.org/10.1038/s41559-017-0367-4

International audience Our basic understanding of plant litter decomposition informs the assumptions underlying widely applied soil biogeochemical models, including those embedded in Earth system models. Confidence in projected carbon cycle-climate feedbacks therefore depends on accurate knowledge about the controls regulating the rate at which plant biomass is decomposed into products such as CO2. Here we test underlying assumptions of the dominant conceptual model of litter decomposition. The model posits that a primary control on the rate of decomposition at regional to global scales is climate (temperature and moisture), with the controlling effects of decomposers negligible at such broad spatial scales. Using a regional-scale litter decomposition experiment at six sites spanning from northern Sweden to southern France-and capturing both within and among site variation in putative controls-we find that contrary to predictions from the hierarchical model, decomposer (microbial) biomass strongly regulates decomposition at regional scales. Furthermore, the size of the microbial biomass dictates the absolute change in decomposition rates with changing climate variables. Our findings suggest the need for revision of the hierarchical model, with decomposers acting as both local- and broad-scale controls on litter decomposition rates, necessitating their explicit consideration in global biogeochemical models.