European beech seedlings from different populations were studied to see how they respond to drought. The researchers found that drought mainly affects how the seedlings exchange gases, with a critical point at around 30-26% soil water availability. The seedlings can adjust their water use efficiency and balance well under severe water stress. Different beech populations show varying responses to drought, but overall, there isn't a clear difference in drought tolerance. By looking at both functional and structural traits, we can better understand how beech seedlings cope with limited water and predict how they might adapt to future environmental changes.