Aims The region around the South China Sea is a relatively independent semi closed geographical unit, which can be divided into eight areas, including the coast of South China, Hainan Island, Taiwan Island, Indo-China Peninsula, Malay Peninsula, Kalimantan Island, Palawan Island, and Luzon Island. The region around the South China Sea is one of the regions with the most concentrated distribution of mangrove plants in the world. This study aims to explore the geographical distribution pattern and the underlying mechanisms of mangrove species in the eight regions around the South China Sea.
Methods Species richness and distribution of mangrove in the region around the South China Sea and other regions worldwide were obtained through extensive literature survey and mapped with ArcGIS. Species distribution map with 1° × 1° grid of four typical mangrove taxa, i.e. Rhizophoraceae, Malvaceae, Sonneratia, Avicennia, were drawn by DIVA-GIS 7.5.0. The migration history and route and its main influencing factors were explored through literature survey in ISI Web of Science.
Important findings (1) There are 39 species of true mangroves and 14 species of semi-mangroves distributed in this region, mostly distributed in Malay Peninsula, Kalimantan Island, Hainan Island, Indo-China Peninsula, Luzon Island. (2) All mangrove species are widespread in the region, which may be caused by the fact that South China Sea has completely different ocean current and monsoon directions in summer and winter, promoting the long-distance dispersals of mangrove plants. (3) There is a certain internal circulation in the northern and southern parts of the South China Sea, and resulting in the appearance of relatively isolated genetic lineages on both sides of the line connecting Cam Ranh Bay and the northern tip of Palawan Island, especially for the true mangroves such as Excoecaria agallocha, Lumnitzera racemose and Aegiceras corniculatum. (4) The sea level decreased by about 120 m during the Pleistocene, which profoundly affected the distribution pattern and migration route of mangroves in the region. In the future, phylogeographical studies using updated molecular technology, especially genomic data, is suggested to explore the dispersal history of mangrove plants and their future evolutionary trend under global climate change.