Species composition and carbon stock estimation in Pulau Sembilan secondary mangrove forests, North Sumatra, Indonesia

This study aimed to identify the species composition and measure the carbon stock estimation from the secondary mangrove forest. Analysis of vegetation (tree, sapling, and seedling) was carried out at Pulau Sembilan, Langkat, North Sumatra, Indonesia. The development of the seedlings, saplings, and trees was determined from four transect lines. Each transect had 100 m length. Each measured plot of total four transects contained 30 plots. The result showed that Rhizophora apiculata predominated vegetation types of seedlings, saplings, and trees in the mangrove forest, with the highest importance value index (116.13%). On the other hand, Bruguiera parviflora had the highest IVI (71.37%) of saplings, while at seedlings and tree levels were dominated by R. apiculata with IVI, 65.30%, and 75.48%, respectively. The diversity index of Shannon-Weiner ranged 1.11-1.49 at the secondary mangrove forest. In secondary mangrove forests had total biomass of trees at 51,589.83 kg/ha with a carbon potential of 23.73 tons/ha. This study provided a basis for rehabilitation, mangrove management and enrichment information in secondary mangrove forests.