Evidence and Theoretic Basis for Enhancing Forest Drought Resilience through the Protection of Old Trees

Global afforestation and forest expansion have substantially altered forest age structures, leading to an increasing dominance of younger stands. Ecological theories such as size‐asymmetric competition and growth–defense trade‐offs suggest that age‐related shifts in resource allocation and size may influence drought responses, yet empirical evidence remains limited. Here, we use tree-ring records from 1,089 sites across China to examine age-dependent patterns of drought resilience, quantified in terms of resistance and recovery. Our results show that recovery capacity generally increases with tree age, whereas resistance displays a non-linear relationship, declining at younger ages before increasing beyond an age threshold. These findings highlight systematic age-related differences in drought resilience across climatic gradients and suggest that forest age structure may play an important role in mediating forest responses to increasing drought stress. Our results provide observational evidence relevant for understanding forest vulnerability and resilience under ongoing climate change.