Tipping Points in Bacterial Richness Amplify Extracellular Enzyme Activities in Northern Peatlands
Year: 2026
Type: article
Abstract: Bacterial communities are vital to northern peatlands' carbon and nutrient cycling, one of the Earth's largest terrestrial carbon stores. However, their diversity and ecological roles at broad geographic scales remain partially understood, limiting our ability to predict their response to global change. Here, we combine a trans-Holarctic survey across 171 Sphagnum-dominated peatlands (SDPs) with a continental-scale reciprocal transplantation experiment to quantify how bacterial diversity shapes carbon and nutrient cycling across bioclimatic gradients. We show that bacterial diversity and composition differ markedly among peatland bioclimatic regions and are primarily structured by the universal abiotic drivers of northern ecosystems: minimum temperature, snow cover, and soil water content. Ecological models further revealed that deterministic processes accounted for approximately 80% of bacterial community assembly, highlighting the strong influence of environmental filtering. Biodiversity-Ecosystem Function analyses identified bacterial richness as a key driver of carbon and nutrient cycling. Using moving-window structural equation models, we identified a critical bacterial richness threshold, below which extracellular enzyme activities increased by ~60%. This transition coincided with stronger environmental filtering and shifts towards bacterial communities with a greater predicted potential for extracellular nutrient acquisition and heterotrophic metabolism. Together, these findings demonstrate that bacterial richness underpins peatland biogeochemical functioning and suggest that biodiversity loss may accelerate carbon turnover, weakening the capacity of northern peatlands to retain carbon. As climate change threatens this unique microbiome, safeguarding bacterial diversity will be critical for maintaining ecosystem resilience and the stability of this globally important carbon sink.
Source: Global Change Biology
DOI: 10.1111/gcb.71099
Authors: Vincent E. J. Jassey, Tristan Lafont Rapnouil, Marie Le Geay, Romain Walcker, Laure Gandois, Maialen Barret, Nicolas Fanin, Bjorn J. M. Robroek, Béatrice Lauga, Luke O. Andrews, Alix Badré Greuza, Mark R. Bakker, Guillaume Bertrand, Tobias Birkwald, Paulo A. V. Borges, Brian Branfireun, Francis Q. Brearley, Cécile Brousseau, Zhao‐Jun Bu, Jean‐François Carrias, Sarah Coffinet, Bruno Corbarra, Eduardo M. F. Dias, Ellen Dorrepaal, André‐Jean Francez, Yuwen Fu, Marvin Gabriel, Rosalina Gabriel, Stéphanie Gerin, Daniel Gilbert, Sébastien Gogo, Gustaf Granath, Emma Gray, Liam Heffernan, Thierry J. Heger, Sari Juutinen, Paul Kardol, Edgar Karofeld, Agata Klimkowska, Martin Küttim, Liisa Küttim, Olivia Kuuri‐Riutta, Terri Lacourse, Mariusz Lamentowicz, Gaël Le Roux, Zoë Lindo, Roy Mackenzie, Katarzyna Marcisz, Yuri A. Mazei, Natalia G. Mazei, Cândida M. F. Mendes, Edward A. D. Mitchell, Juanita Mora‐Gomez, Raphael Müller, Kathy Pouliot, Anna‐Helena Purre, Achim Quaiser, Brenda Riquelme‐del Río, Allison R. Rober, Line Rochefort, Ana C. Rodríguez, A. Britta K. Sannel, Fabian Seemann, Laurent Servière, Maria Strack, Graeme T. Swindles, Julie Talbot, Andrey N. Tsyganov, Eeva‐Stiina Tuittila, Alexander T. Tveit, Minna M. Väliranta, Kevin H. Wyatt, Henni Ylänne, Zicheng Yu, Evgeny A. Zarov, Samuel Hamard
Institutions: Centre National de la Recherche Scientifique, Institut National Polytechnique de Toulouse, Institut de Recherche pour le Développement, Centre de Recherche sur la Biodiversité et l'Environnement, Université de Toulouse, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Institut de Recherche en Horticulture et Semences, Université d'Angers, École Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine, Radboud University Nijmegen, Université de Pau et des Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, University of Liverpool, Liverpool John Moores University, Association Francaise contre les Myopathies, France Énergies Marines, Federal Office of Sport, Laboratoire Chrono-Environnement, Université Marie et Louis Pasteur, Biosphärenreservat Rhön, Universidade dos Açores, Western University, Manchester Metropolitan University, Northeast Normal University, Université Clermont Auvergne, Laboratoire Microorganismes Génome et Environnement, Ecosystèmes, Biodiversité, Evolution, Université de Rennes, Instituto de Investigação e Tecnologia da Agronomia e Meio Ambiente, Umeå University, Chinese Academy of Sciences, Northeast Institute of Geography and Agroecology, Nature And Biodiversity Conservation Union, Finnish Meteorological Institute, Atlantic Technological University, Vrije Universiteit Amsterdam, HES-SO University of Applied Sciences and Arts Western Switzerland, CHANGINS - Haute école de viticulture et œnologie, Swedish University of Agricultural Sciences, University of Tartu, University of Antwerp, Wetlands International, Tallinn University, University of Eastern Finland, University of Victoria, Adam Mickiewicz University in Poznań, Universidad Autónoma de Chile, Instituto de Biodiversidad de Ecosistemas Antárticos y Subantárticos, Universidad de Magallanes, Lomonosov Moscow State University, Shenzhen MSU-BIT University, University of Neuchâtel, Université d'Orléans, Bureau de Recherches Géologiques et Minières, Institut des Sciences de la Terre d'Orléans, University of Vienna, Center for Northern Studies, Université Laval, The Ohio State University, Stockholm University, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, University of Waterloo, Queen's University Belfast, Université de Montréal, Russian Academy of Sciences, Severtsov Institute of Ecology and Evolution, UiT The Arctic University of Norway, University of Helsinki, Yugra State University
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Climate action
Open Access status: hybrid
Estimated APC paid: $4,550
Funders: National Science Foundation, U.S. Department of Agriculture, Polarforskningssekretariatet, Agence Nationale de la Recherche, National Natural Science Foundation of China, Svenska Forskningsrådet Formas, Vetenskapsrådet, Russian Science Foundation, U.S. Forest Service, Pacific Northwest Research Station
Awards: Transitions: Metagenomics of aquatic biofilms: evaluating linkages between autotrophic and heterotrophic microbial diversity and function, LTER: Cross-scale controls over responses of the Alaskan boreal forest to changing disturbance regimes, G195474297, G2574603407, G297560563, G3529253369, Rethinking the peatland carbon cycle - identifying the role of mixotrophs in the biological carbon pump, Microbial CO2 exchanges in peatlands: contribution to the peatland carbon pool and response to climate change, G4879612124, Swedish Infrastructure for Ecosystem Science - SITES, G5258843564, G5856818476, The bryosphere as mediator of carbon cycling in boreal forests, G6281195295, G6803667113, G692865722, G7080048889, The driving role of the microbial carbon balance in ecosystem responses to climate change
OpenAlex ID: W7213557665