The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests

Roberto Salomón , Richard Peters , Roman Zweifel (1) , Ute Sass-Klaassen (2) , Annemiek Stegehuis , Marko Smiljanic (3) , Rafael Poyatos (4) , Flurin Babst (1) , Emil Cienciala , Patrick Fonti (1) , Bas Lerink , Marcus Lindner (5) , Jordi Martinez-Vilalta (4, 6) , Maurizio Mencuccini (4) , Gert-Jan Nabuurs , Ernst van der Maaten (7) , Georg von Arx (1) , Andreas Bär , Linar Akhmetzyanov , Daniel Balanzategui (8) , Michal Bellan , Jörg Bendix , Daniel Berveiller , Miroslav Blaženec , Vojtěch Čada , Vinicio Carraro , Sébastien Cecchini , Tommy Chan , Marco Conedera , Nicolas Delpierre , Sylvain Delzon , Ľubica Ditmarová , Jiri Dolezal , Eric Dufrêne , Johannes Edvardsson , Stefan Ehekircher , Alicia Forner , Jan Frouz , Andrea Ganthaler , Vladimír Gryc , Aylin Güney , Ingo Heinrich , Rainer Hentschel , Pavel Janda , Marek Ježík , Hans-Peter Kahle , Simon Knüsel , Jan Krejza , Łukasz Kuberski , Jiří Kučera , François F. Lebourgeois (9) , Martin Mikoláš , Radim Matula , Stefan Mayr , Walter Oberhuber , Nikolaus Obojes , Bruce Osborne , Teemu Paljakka , Roman Plichta , Inken Rabbel , Cyrille Rathgeber , Yann Salmon , Matthew Saunders , Tobias Scharnweber , Zuzana Sitková , Dominik Florian Stangler , Krzysztof Stereńczak , Marko Stojanović , Katarína Střelcová , Jan Světlík , Miroslav Svoboda , Brian Tobin , Volodymyr Trotsiuk , Josef Urban , Fernando Valladares , Hanuš Vavrčík , Monika Vejpustková , Lorenz Walthert , Martin Wilmking , Ewa Zin , Junliang Zou , Kathy Steppe

1 Swiss Federal Institute for Forest, Snow and Landscape Research WSL
2 WUR - Wageningen University and Research [Wageningen]
3 Universität Greifswald - University of Greifswald
4 CREAF - Centre for Ecological Research and Applied Forestries
5 EFI - European Forest Institute
6 UAB - Universitat Autònoma de Barcelona
7 Institute for Forest Growth
8 GFZ - German Research Centre for Geosciences - Helmholtz-Centre Potsdam
9 SILVA - SILVA

Abstract Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites. Relative to the two preceding years, annual stem growth was not consistently reduced by the 2018 heatwave but stems experienced twice the temporary shrinkage due to depletion of water reserves. Conifer species were less capable of rehydrating overnight than broadleaves across gradients of soil and atmospheric drought, suggesting less resilience toward transient stress. In particular, Norway spruce and Scots pine experienced extensive stem dehydration. Our high-resolution dendrometer network was suitable to disentangle the effects of a severe heatwave on tree growth and desiccation at large-spatial scales in situ, and provided insights on which species may be more vulnerable to climate extremes.

Domains: Biodiversity and Ecology; Global Changes

Roberto Salomón, Richard Peters, Roman Zweifel, Ute Sass-Klaassen, Annemiek Stegehuis, et al.. The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests. Nature Communications, 2022, 13 (1), pp.28. ⟨10.1038/s41467-021-27579-9⟩. ⟨hal-03880254⟩