Can trees harden up to survive global change-type droughts?

Extract

This scientific commentary refer to ‘Acclimation of hydraulic and morphological traits to water deficit delays hydraulic failure during simulated drought in poplar’ by Lemaire et al. (doi:10.1093/treephys/tpab086).

As we leave behind another extreme summer that hit several areas of the Northern Hemisphere, bringing prolonged heat waves and drought in some regions and massive rainfalls and floods in others, worries about the impacts on forest ecosystems rise (Allen et al. 2015). Recent decades have seen an increase in the rates of tree mortality caused by drought, and projections for the future are not optimistic (Adams et al. 2017, Senf et al. 2020). Scientists are struggling to understand in depth the mechanistic bases of drought-induced pathways to tree death, in the view of better predicting which tree species and forests are at higher risk of decline in the coming years, and understanding the set of functional traits allowing some trees to endure extreme drought better than others. This knowledge is urgently needed to inform and guide management of forest ecosystems, by developing conservation policies, promoting forest regeneration and/or implementing new plantations (Millar et al. 2007, Bradford and Bell 2017).