Research on Seed Plant Flora of Dalian Island in Pintan

Dalian Island in Pingtan was surveyed roundly to species resources by means of investigating typical sampling plots and transect lines. Based on field investigation data and related references, the flora distribution of the family and genus in the region were analyzed, which were compared with the neighboring islands in Pingtan and mainland mountains. The results showed that the seed plants were rich in species diversity, represented by 233 species, belonging to 192 genera in 64 families. In terms of family composition, the dominant families are Compositae, Poaceae, Fabaceae and Rosaceae, which contain 75 genera and 83 species, accounting for 39.06% and 35.62% of the total genera and genera. The single families and genera were dominant in this flora, accounting for 40.63% and 83.85% respectively. Herbaceous was the main life form, accounting for 54.94%. Shrubs accounted for 32.19%. Trees and vines accounted for 7.30% and 5.58% respectively. The floristic composition was complex and diverse. At the family level, the floras were mainly tropical component, which accounted for 80.56%. The temperate component only accounted for 19.44%. Pan-tropical component accounted for 34.38%. At the genus level, the tropical component accounted for 59.39%, the temperate component accounted for 40%, which showed the flora transition from tropical component to temperate component. The R/T values of family and genus were 4.14 and 1.48 respectively. The tropical characteristics were dominant in this flora. Compared with different regions, the dominant family of Dalian Island was closely related to islands in Pingtan, but distantly related to that of Meihuashan Nature Reserve. The R/T values of Dalian Island were significantly lower than those of uninhabited islands in Pingtan, but higher than those of the three mountains. In terms of geographical kinship, the floristic distribution type of Dalian Island was closely related to islands in Pingtan, which were mainly composed of tropical elements, but distantly related to mainland mountains.