Diversity of Brachyuran crabs after 12 years natural reforestation at destroyed areas by typhoon Durian in Can Gio mangrove

Abstract

The regeneration of mangroves in Can Gio following typhoon Durian has been the subject of interesting research, with the hope of developing plans to deal with similar consequences in the future. In this study, we recorded 26 species of crabs belonging to 16 genera and 10 families, of which the Sesarmidae and Ocypodidae families accounted for the highest proportion. The natural reforestation in the destroyed area by the previous Durian typhoon in 2006 has recorded the appearance of 6 new recorded species such as Paracleistostoma depressum, Pilumnopeus sp., Macrophthamus japonicus, Myomenippe hardwickii, Nanosesarma pontianacense and Uca annulipes. Particularly, Perisesarma eumolpe was the dominant species in all areas, indicating their ability to adapt to many habitats. Several new recorded species, especially Uca crabs, were recorded in naturally regenerated areas. The densities and biomass of crabs in regenerated areas were higher than those in intact forests. Shannon Weiner index indicated that the crab community had higher diversity in the regenerated areas. On the contrary, in the intact forest, the Simpson dominance index is higher than in the regenerated areas. The results of this study indicated that natural regeneration has created conditions for the crab community to recover opportunities for many new species to appear. The open canopy of monoculture forests would contribute to increasing the number of crabs,in particular and biodiversity, in general. Retaining the natural conditions after the typhoon had shown effectiveness in helping the ecosystem recover.