Abstract:Shrubland communities, as an important component of island ecosystem, play a significant role in maintaining regional biodiversity and ecosystem functions. A systematic investigation was conducted on the typical shrub communities of Dongshan Island using standard quadrat method, and their species composition, community structure, floristic characteristics, and species diversity were analyzed, as well as explored the relationship between species diversity and environmental factors through redundancy analysis (RDA). The results showed that a total of 174 vascular plant species, belonging to 66 families and 147 genera, were recorded in 68 sample plots, with Asteraceae, Fabaceae, and Poaceae as dominant families. Tropical components were the main constituents of the typical shrub communities on Dongshan Island, while temperate components were important supplements to the island’s flora. The species composition and structure of the nine types of shrub communities vary significantly. The Eurya emarginata shrub community and the Acacia confusa shrub community had the richest species composition, with higher Patrick richness index, Shannon-Wiener index and Pielou evenness index, while the Volkameria inermis shrub community and the Lantana camara shrub community had the lowest. The RDA results showed that soil factors (total soil phosphorus content and alkali-hydrolyzable nitrogen content) were the important driving factors affecting the species diversity of the native shrub layer, while the species diversity of the naturalized/ invasive shrub communities is mainly influenced by altitude, distance from the coastline and total water-soluble salt content in the soil.
