Relationships between vegetation and soil seed banks along a center-to-edge gradient on a tropical coral island
Few studies have focused on the relationships between vegetation and soil seed banks on small islands. To better understand the pattern and regeneration potential of seed banks on tropical coral islands, we measured environmental factors and the species composition, and species richness of soil seed banks and vegetation along a gradient from the center to the edges on East Island in the South China Sea. The results showed that the similarity between the species composition of vegetation and seed banks increased from the center to the edge. In the center, species richness in both vegetation and seed banks was positively correlated with soil organic matter, total nitrogen, and total phosphorus. At the edge, species richness in both vegetation and seed banks was positively correlated with soil pH. Our results indicate that plant communities contributed little to the seed banks in the center of the island and evidently played a minor role in vegetation regeneration at that location. Plant communities near the edge, in comparison, showed a greater potential for regeneration from seed banks. Conservation and management practices along the center-to-edge gradient should be designed in accordance with the differences in plant communities and soil seed banks at different locations on the gradient.