Distribution and status of three endangered mangrove plants of the genus Sonneratia

Sonneratia is the most endangered genus of mangrove plants in China. Among the six existing mangrove species in Sonneratia, S. ovata Backer, S. × hainanensis W.C. Ko, E.Y. Chen & W.Y. Chen, and S. × gulngai N.C. Duke & B.R. Jackes are all critically endangered. In this paper, we explored the distribution and status of these three Sonneratia mangrove plants based on literature review and field investigation. Results identified two natural and three artificial populations of S. ovata, with 231 and 38 individuals, respectively; four natural and two artificial populations of S. × hainanensis, with 139 and 11 individuals, respectively; and four natural and three artificial populations of S. × gulngai, with 345 and 12 individuals, respectively. The natural regeneration ability of the populations was extremely poor, with no new individuals in the artificial populations. Climate change and human disturbance are the main reasons for the decrease in Sonneratia species, and poor self-regeneration is a limiting factor for population size recovery. To strengthen in situ protection, ex situ conservation strategies should be optimized, artificial breeding research should be strengthened, breakthroughs in breeding difficulties should be accelerated, and returning populations should be scientifically cultivated to ensure normal population development.