Nikita Häfeli successfully defended her MSc thesis!


We congratulate Nikita Häfeli for successfully defending her MSc today. In her master's thesis “Experimentally separating drought from heat stress in European beech trees” Nikita used the phytotron facility of the PPE group to experimentally test the individual and combined effects of drought, heat and elevated vapor pressure deficit (VPD) on the performance and survival of European beech saplings. By applying an elaborated factorial experimental design, she could investigate soil drought effects on trees independent of low air humidity (high VPD) and heat stress. Nikita could show that elevated VPD and heat had no significant effect on the survival time of the saplings under drought, but high VPD in combination with heat led to increased leaf damage independent of the irrigation treatment. Drought also induced a strong decline of carbon reserves in sapwood, which was especially strong under high temperatures in combination with elevated VPD. Nikita’s thesis revealed new insights on the biological consequences of summer drought events for our forests.