Abstract:

Aim: Fujian Province is made up of numerous islands that are rich in endemic plant resources. Conducting research on their distribution patterns and mechanisms of diversification can provide a basis for conservation and protection of coastal endemic plants. Our aim is to investigate the distribution patterns and mechanisms of species richness of coastal endemic plants in Fujian islands.
Methods: This study investigated the species-area relationship of coastal endemic plants in 53 islands of Fujian Province as well as the impact of 10 environmental factors on plant species richness from three sources: landscape, human disturbance, and climate. Differential responses by various growth forms of plants, such as trees, shrubs, and herbs, to environmental factors were also discussed.
Results: The species-area relationship between coastal endemic plants and different growth forms of plants showed a trend of increasing species richness with increasing area. The area, shape index, and perimeter area ratio of environmental factors of the landscape were the main factors that explain the abundance of coastal endemic plants and different growth forms of species on Fujian islands. Both the coastal endemic plants and their differing growth forms increased as the area and shape index increased, while the coastal endemic plants species richness as well as shrub and herb richness decreased with an increase in the perimeter area ratio. Further, the various growth forms exhibited differential species richness responses to island environmental factors. Apart from landscape factors, climate had the highest interpretation rate for trees, reaching 9.82%.
Conclusion: Compared to other island ecosystems, the species richness of coastal endemic plants and different growth forms in the Fujian islands is strongly correlated with island area, but are less sensitive to island habitats. Landscape environmental factors contributed more to the interpretation rate than climate and human disturbance. Previous studies have found that island environmental factors are significantly correlated with habitat heterogeneity. For example, the larger the island, the more irregular its shape, and the lower its perimeter area ratio, the higher the habitat heterogeneity. Therefore, the high level of habitat heterogeneity in this study may be the underlying mechanism that explains the changes in coastal endemic plant abundance with landscape environmental factors.

Key words: species richness, island biogeography, growth form, species-area relationship, habitat heterogeneity