Invasive capacity of the mangrove Sonneratia apetala in Hainan Island, China.

摘要

The mangrove Sonneratia apetala has been introduced into China since 1985 as a plantation species in coastal area. There has been long time speculation regarding the invasive capacity of this species and its contribution to the degradation of native plant communities. In this study, we evaluated in the field the invasive capacity of S. apetala by investigating its dispersal, recruitment and regenerative capacity in the Dongzhai Harbour region of Hainan Island, China. Remotely sensed data showed that the total area of S. apetala plantings decreased from 20 ha in 1999 to 17.68 ha in 2010. Community investigation data showed that S. apetala was the dominant species with 57.3% of average IVI (importance value index) in S. apetala communities, while its natural regeneration did not occur at regular intervals. The seedling dispersal analysis revealed that individuals of S. apetala did not prevent seedlings of other species from establishing, indicating that S. apetala did not keep other species from growing into mangrove communities. Meanwhile, no evidence was found to show that S. apetala was an invasive species competing with the native species. On the contrary, S. apetala acted primarily as a pioneer tree species in the coastal environments of Hainan Island.