Tropical forests often experience phosphorus (P) limitation due to prolonged weathering, yet adult trees can sustain high growth rates through various P acquisition strategies despite extremely low soil P concentrations. These strategies carry substantial carbon costs, which may be particularly constraining for seedlings with limited carbon budgets under low light conditions in the forest understory. As a result, P limitation may exert stronger environmental filtering at the seedling stage. This research investigates whether P acquisition and allocation traits shift from the seedling to the adult stage. Specifically, it examines whether seedlings exhibit similar belowground traits, such as root phosphatase activity, and P allocation strategies as adult trees of the same species. I hypothesize that seedlings rely more on low-carbon scavenging strategies to maximize soil exploration in low-P soils, whereas adult trees adopt carbon-intensive P-mining strategies. By linking shifts in P strategies across life stages, this study aims to inform reforestation and forest management by identifying developmental stages most vulnerable to P limitation.