An increase in average air temperatures, associated with an increase in frequency and duration of
heat waves, rising levels of atmospheric CO2 concentration [CO2], and alterations in precipitation
patterns, resulting in more frequent and intense drought periods, have been predicted throughout
this century. Changing climate regimes have a major impact on plant growth and physiology,
resulting in widespread tree mortality, but these climate-induced effects are still poorly
understood. In this project, we aim at determining the effects of elevated temperature (including
heat waves) and [CO2], either alone or in concert with drought, on tree seedling growth and
hydraulic functioning. Two indigenous tree species, Populus tremula and Quercus robur, will
therefore be grown in treatment chambers under different conditions in temperature, [CO2] and
soil water availability. State-of-the-art plant sensors, combined with discrete physiological
measurements and thermal imaging, will be used to bridge the important knowledge gap about
tree hydraulic functioning under changing climate regimes. With this project we aim to answer
outstanding questions on tree seedling strategies to survive drought and (extreme) heat stress
under ambient and elevated [CO2] by adapting wood anatomical traits and hydraulic function. This
is of vital importance for policy makers and forest managers in order to make thoughtful decisions
to ensure maximum resilience of Flemish forests in a changing climate.