Abstract: Winter buds play a crucial role in regulating stem and leaf development. However, the cold resistance and their adaptive strategies have not been fully understood. In this study, we examined the morphological (maximum length), biochemical (water content, concentrations of nonstructural carbohydrates, total starch content and total soluble sugar) and physiological (the low semi-lethal temperature, LT50) traits of winter bud across 72 common woody species in a species-rich subtropical evergreen broad-leaved forest in Eastern China. Despite substantial interspecific variation in winter bud traits, total soluble sugar content showed phylogenetic conservation, with closely related species exhibiting similar levels. Evergreen broad-leaved species demonstrated higher cold resistance (lower LT50) than deciduous broad-leaved species, aligning with their resistance rather than avoidance strategies. Scaly buds had stronger cold resistance than naked buds, and bud length and carbohydrate storage were positively associated with cold resistance. At the organ level, the physiological cold resistance of winter buds is positively influenced by both their morphology and carbohydrate storage (concentrations of nonstructural carbohydrates and total soluble sugar), and also positively influenced by the whole plant economics spectrum at the species level. However, the morphological and biochemical traits of winter buds represent another new dimension decoupled from the whole plant economics spectrum. Our findings highlight winter bud traits as a complex but long-neglected functional dimension of species’ adaptive strategies to cope with cold temperatures in evergreen broad-leaved forests, and provides perspectives at different levels (organs and species) for understanding plant adaptations to winter bud growth.

Key words: Winter buds, Cold resistance, Plant functional traits, Subtropical evergreen broad-leaved forests, Leaf economic traits