Composition and Structure of Ajkwa Island Mangrove Vegetation

Ajkwa Island exist in the Ajkwa estuary in Mimika Regency, Central Papua, Indonesia. Mangroves on Ajkwa Island are secondary forests formed by the natural succession process of the mangrove ecosystem in the Ajkwa Estuary. This study aimed to understand how the mangrove ecosystem on Ajkwa Island develops from a secondary mangrove forest to a primary mangrove forest. The plot transect method was used for field data collection at each station. The structure of the mangrove vegetation was analyzed in three categories: trees, saplings, and seedlings. A total of 13 mangrove species were encountered on Ajkwa Island, including nine major component species, one minor component species, and three associated mangrove species. Ajkwa Island is dominated by mangrove pioneer species from families Acanthacea and Lyrtaceae. Sonneratia alba had the highest important value index (IVI) for the tree categories in each data collection year on Ajkwa Island. In 2012, Sonneratia alba had the highest IVI value for the sapling category on Ajkwa Island, but in 2021 and 2024, Rhizophora apiculata had the highest IVI value. The sediment type on Ajkwa Island was medium silt. Based on these data, the mangrove vegetation structure of Ajkwa Island continues to progress toward primary mangroves.