Drought adaptation mechanisms in Quercus acutissima: Physiological, hydraulic, and ecological strategies

Increasingly frequent drought events driven by climate change pose a significant threat to Quercus acutissima, a widely distributed species crucial for biodiversity conservation, soil stabilization, and plantation forestry in East Asia. Understanding its multidimensional adaptive mechanisms is essential for the sustainable management of this species in water-limited environments. This review synthesizes recent research across physiological, hydraulic, morphological, and ecological scales to comprehensively evaluate the response strategies of Q. acutissima to water deficit. Physiologically, the species exhibits pronounced overcompensatory recovery following drought and rewatering cycles and demonstrates a stress imprint effect, indicating ecological memory. Nitrogen and phosphorus addition effectively mitigates drought-induced reductions in the leaf structural traits, highlighting the role of nutrient management. Hydraulically, the species adopts a relatively risk-taking strategy characterized by a weak efficiency-safety tradeoff, but mitigates this risk through strong vulnerability segmentation, prioritizing the protection of main stems over expendable terminal organs. It also displays hydraulic lift and highly flexible seasonal water use, shifting between shallow and deep soil layers, which facilitates water complementarity in mixed plantations. Furthermore, the species is positioned at the fast investment-acquisition end of the leaf economics spectrum, exhibiting high phenotypic plasticity that favors rapid growth in resource-rich periods but increases its vulnerability under severe and prolonged drought. This vulnerability is further amplified by compound stressors, such as the synergistic negative effects of concurrent drought and defoliation, which severely deplete essential carbohydrate reserves. Ultimately, while these multiscale strategies explain their broad ecological amplitude, their acquisitive nature necessitates integrated silvicultural practices, such as optimized mixed species configurations and nutrient management, to reduce cumulative damage under climate extremes. Future research should prioritize long term field studies and belowground ecological dynamics