Tracing the fate of water following foliar uptake in beech ( <i>Fagus sylvatica</i> L.) using positron imaging

These findings demonstrate that FWU may actively contribute to replenishing branch water pools, emphasizing its role as a critical hydraulic mechanism. This research underscores the utility of integrating PET imaging with complementary methods to better understand FWU dynamics and its implications for plant water budgets under changing climatic conditions.