Belowground impacts of alpine woody encroachment are determined by plant traits, local climate, and soil conditions

• Published in: Global Change Biology
• Main Authors: Collins, Courtney, Spasojevic, Marko, Alados, Concepción, Aronson, Emma, Benavides, Juan, Cannone, Nicoletta, Caviezel, Chatrina, Grau, Oriol, Guo, Hui, Kudo, Gaku, Kuhn, Nikolas, Müllerová, Jana, Phillips, Michala, Pombubpa, Nuttapon, Reverchon, Frédérique, Shulman, Hannah, Stajich, Jason, Stokes, Alexia, Weber, Sören, Diez, Jeffrey
• Other Authors: Institute of Arctic Alpine Research University of Colorado Boulder (INSTAAR), University of Colorado Boulder, University of California Riverside (UC Riverside), University of California (UC), Instituto Pirenaico de Ecologìa = Pyrenean Institute of Ecology Zaragoza (IPE - CSIC), Pontificia Universidad Javeriana (PUJ), Universitá degli Studi dell’Insubria = University of Insubria Varese (Uninsubria), Université de Bâle = University of Basel = Basel Universität (Unibas), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Nanjing Agricultural University (NAU), Hokkaido University Sapporo, Japan, Instituto de Ecologia (INECOL), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-16-CE03-0009,ECOPICS,Services écosystémiques souterrains produits par les communautés végétales le long de gradients altitudinaux en France et au Mexique(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Alpine; Global change; Leaf traits; Plant–soil interactions; Soil microbes; Woody encroachment; [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics; Phylogenetics and taxonomy; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Arctic
• Online Access: https://hal.inrae.fr/hal-03006624; https://hal.inrae.fr/hal-03006624/document; https://hal.inrae.fr/hal-03006624/file/gcb.15340.pdf; https://doi.org/10.1111/gcb.15340

International audience Global climate and land use change are causing woody plant encroachment in arctic, alpine, and arid/semi-arid ecosystems around the world, yet our understanding of the belowground impacts of this phenomenon is limited. We conducted a globally distributed field study of 13 alpine sites across four continents undergoing woody plant encroachment and sampled soils from both woody encroached and nearby herbaceous plant community types. We found that woody plant encroachment influenced soil microbial richness and community composition across sites based on multiple factors including woody plant traits, site level climate, and abiotic soil conditions. In particular, root symbiont type was a key determinant of belowground effects, as Nitrogen-fixing woody plants had higher soil fungal richness, while Ecto/Ericoid mycorrhizal species had higher soil bacterial richness and symbiont types had distinct soil microbial community composition. Woody plant leaf traits indirectly influenced soil microbes through their impact on soil abiotic conditions, primarily soil pH and C:N ratios. Finally, site-level climate affected the overall magnitude and direction of woody plant influence, as soil fungal and bacterial richness were either higher or lower in woody encroached versus herbaceous soils depending on mean annual temperature and precipitation. All together, these results document global impacts of woody plant encroachment on soil microbial communities, but highlight that multiple biotic and abiotic pathways must be considered to scale up globally from site- and species-level patterns. Considering both the aboveground and belowground effects of woody encroachment will be critical to predict future changes in alpine ecosystem structure and function and subsequent feedbacks to the global climate system. © 2020 John Wiley & Sons Ltd