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

Heatwaves severely impact forest ecosystems, but their effects on individual trees and species across large areas are not well understood. This study investigated the effects of the 2018 European heatwave on tree growth and water status using high-resolution dendrometer data from 21 species across 53 sites. While annual stem growth wasn't consistently reduced, stems showed significantly more temporary shrinkage due to water loss. Conifers rehydrated less effectively than broadleaves, suggesting lower resilience to stress. Norway spruce and Scots pine experienced considerable dehydration.

Roberto L. Salomón, Richard L. Peters, Roman Zweifel, Ute G. W. Sass-Klaassen, Annemiek I. Stegehuis, Marko Smiljanic, Rafael Poyatos, Flurin Babst, Emil Cienciala, Patrick Fonti, Bas J. W. Lerink, Marcus Lindner, Jordi Martinez-Vilalta, Maurizio Mencuccini, Gert-Jan Nabuurs, Ernst van der Maaten, Georg von Arx, Andreas Bär, Linar Akhmetzyanov, Daniel Balanzategui, 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 Lebourgeois, Martin Mikoláš, Radim Matula, Stefan Mayr, Walter Oberhuber, Nikolaus Obojes, Bruce Osborne, Teemu Paljakka, Roman Plichta, Inken Rabbel, Cyrille B. K. 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