Global buffering of temperatures under forest canopies

Pieter de Frenne (1) , Florian Zellweger (2) , Francisco Rodríguez-Sánchez , Brett Scheffers , Kristoffer Hylander (3) , Miska Luoto (4) , Mark Vellend (5) , Kris Verheyen (6) , Jonathan Roger Michel Henri Lenoir (7)

1 Forest & Nature Lab - Department of Plant Production
2 Unibas - Université de Bâle = University of Basel = Basel Universität
3 Stockholm University
4 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
5 UBC - University of British Columbia
6 UGENT - Universiteit Gent = Ghent University
7 EDYSAN - Ecologie et Dynamique des Systèmes Anthropisés - UMR CNRS 7058

Macroclimate warming is often assumed to occur within forests despite the potential for tree cover to modify microclimates. Here, using paired measurements, we compared the temperatures under the canopy versus in the open at 98 sites across 5 continents. We show that forests function as a thermal insulator, cooling the understory when ambient temperatures are hot and warming the understory when ambient temperatures are cold. The understory versus open temperature offset is magnified as temperatures become more extreme and is of greater magnitude than the warming of land temperatures over the past century. Tree canopies may thus reduce the severity of warming impacts on forest biodiversity and functioning.

Domaines: Biodiversité; Ecologie, Environnement; Milieux et Changements globaux; Biodiversité et Ecologie

Pieter de Frenne, Florian Zellweger, Francisco Rodríguez-Sánchez, Brett Scheffers, Kristoffer Hylander, et al.. Global buffering of temperatures under forest canopies. Nature Ecology & Evolution, 2019, 3 (5), pp.744-749. ⟨10.1038/s41559-019-0842-1⟩. ⟨hal-02352625⟩