ABSTRACT Moso bamboo ( Phyllostachys pubescens ), a fast‐growing and potentially invasive species, exhibits culm‐age heterogeneity in structure and physiology; however, its water‐use strategies in relation to aging remain unclear. Thus, we aimed to examine age‐related variations in hydraulic performance, vessel integrity, and nutrient allocation in bamboo culms aged 1–5 years. Sap flux density peaked in 2‐year‐old culms, possibly reflecting the maturation of conductive tissues. However, daily sap flow rates showed no significant age‐dependent differences. Dye tracing and cryo‐scanning electron microscopy revealed consistent axial and radial vessel continuity and low embolism frequency across all age groups, with a relative loss of potential conductivity of approximately 10%. Elemental analysis showed reduced K concentration and delayed Si accumulation in the vessel sap with age, suggesting a physiological shift from osmotic regulation to structural reinforcement. Starch began accumulating in the third year and peaked at age four, indicating a physiological transition from resource consumption to energy storage. These coordinated transitions support sustained water transport across ages and may enhance resilience under drought and interspecific competition. Our findings revealed functional plasticity in water use and resource allocation during culm development, highlighting the physiological mechanisms that may underlie the ecological success and invasive potential of Moso bamboo.
Xiang et al. (Thu,) studied this question.