Abstract:Invasive plants pose a serious threat to the vegetation ecosystem on tropical coral islands. Studying the seed germination characteristics of invasive plants in tropical coral island habitats can provide scientific basis for predicting the expansion potential of invasive plants on tropical coral islands. The seed germination characteristics of invasive species Eupatorium odoratum, Sphagneticola trilobata, and coral island native species E. lindleyanum were compared under the simulated tropical coral island habitat via "3 ℃ warming + marine sand matrix + water". The results showed that the seed germination traits of E. odoratum were mainly affected by marine sand matrix and elevated temperature, while those of S. trilobata and E. lindleyanum were mainly affected by marine sand matrix. In tropical coral island habitats, the reproductive potential of the three plants was significantly lower than that in mainland habitats, in particular for E. odoratum and S. trilobata. The seed expansion potential of E. odoratum was similar to that of E. lindleyanum, but S. trilobata had higher seed expansion potential than E. lindleyanum. Although the reproductive potential of E. odoratum and S. trilobata decreased after being introduced into tropical coral island, the adaptability of their seed germination characteristics to the habitat and the expansion potential of invasive plants were higher than that of native species, indicating that the two invasive plants would pose a threat to the vegetation ecosystem of the tropical coral islands. In the future, it should be focused on the prevention and control of invasive plants in tropical coral islands.