In recent years, cases of widespread forest mortality have been recorded worldwide. Our current understanding still cannot explain why some trees die and some survive, and variation and changes in bark conductance is a plausible hypothesis that I test here. We will study the role of bark in tree survival in dry conditions when stomata are closed due to active regulation thus minimizing foliage water loss and photosynthesis, but water loss through bark and bark photosynthesis continue. We use a unique combination of field and laboratory experiments on bark structure and function and their plasticity to climatic conditions and combine the measurements with modelling of tree hydraulics, regional tree mortality and land-surface modelling to allow improved estimates of species performance and survival in future climate scenarios. The results help us to better understand forest resilience and the integrity of forest carbon sinks in changing climate.

2023

2027