STRUKTUR KOMUNITAS JENIS MANGROVE DI KAWASAN PULAU TUTUS KABUPATEN BULUNGAN
Mangrove forests are a type of coastal forest ecosystem that thrives in intertidal zones, particularly in sheltered shorelines and river estuaries that are inundated during high tide and exposed during low tide. The plant communities in these areas are characterized by their high tolerance to saline conditions. This study aims to identify the species of mangroves present and to analyze their community structure through indices of importance value, species diversity, evenness, and dominance within the Tutus Island region of Bulungan Regency. The findings of this study are expected to support sustainable aquaculture development by preserving the mangrove ecosystem. Environmental factors influencing the distribution and diversity of mangroves were also assessed, with measured parameters indicating a salinity level of 19 ppt and a pH value of 6.80. The research employed the line transect method, with each transect extending 100 meters and sampling plots of 10 x 10 meters established along each transect. Observations revealed the presence of several mangrove species, including Nypa fruticans, Rhizophora spp., and Sonneratia spp. The analysis of community structure yielded a species diversity index of 0.296, a dominance index of 0.628, and a species evenness index of 0.270.