Mangrove is the most productive ecosystem in the coastal area and found vastly in Indonesia. The ecosystem condition has considered being related to environmental settings. Riverine and estuarine mangrove are unique since they have lower salinity and higher carbon and nutrient content than the oceanic sites. A correlative study was conducted along Bintan island aimed to analyze the relationship between mangrove community structure and environmental parameters. As many as 27 10m-x-10m-quadratic plots were scattered in three mangrove forests, such as Kawal, Pengudang, and Lagoi. Hemispherical photography and vegetation data were applied for collecting mangrove community size. On the other hand, soil samples were collected in for organic concentration and soil particle composition analysis. Moreover, we also conducted real-time in-site analysis for pH and salinity of pore-water. The results found that organic matter content had a strong correlation (Pearson: Sig. <0.01) to mangrove canopy coverage, tree density, and diameter size. The silkier substrate tended to have lower mangrove canopy coverage, fewer tree numbers, and larger trunk size. Tree diameter also was influenced by clay and sand concentration. Multidimensional scaling, based on soil particles composition and species distribution, represented that Pengudang and Lagoi were more similar than Kawal due to the geographical position.  The Redundancy analysis (RDA) showed that the species composition on each site was highly influenced by soil content, especially soil particle proportion. The study quantitatively revealed that mangrove size, distribution, and coverage were strongly depended on the environmental proxies.

Keywords: Mangrove, soil organic matter, soil particle composition, canopy coverage, community structure, species distribution.