The island ecosystem, due to its inherent fragility, is highly susceptible to both natural disturbances and human activity, resulting in fragmented habitats for island plant populations. This study investigates the population structure and dynamics of Heliotropium arboreum in such fragmented environments, aiming to understand its survival and adaptability. We selected six H. arboreum populations across different habitats, analyzing their diameter class structures, static life tables, and survival curves through a field survey using sample line investigations. Structural and dynamic characteristics of each population were examined, and future trends predicted using time series analysis. Results indicated that the second, third, and fourth age classes comprised the majority, representing 63%-86% of individuals, suggesting a growing population with an irregular pyramid-like structure. However, some age classes show decline, with weak growth rates, high sensitivity to external disturbances, and low stability. With increasing age, standardized survival numbers declined, mortality rates rose, and survival curves approximated the Deevey Type II pattern. Without intervention, the population is projected to face serious reductions as individuals age, potentially leading to extinction. Thus, we recommend minimizing human interference, implementing targeted protection strategies, increasing research and education, and promoting natural renewal through seedling propagation and artificial cultivation.