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Community Structure, Environmental Drivers, and Cross-Strata Spatial Patterns of Mangroves in the Downstream Poso Watershed, Central Sulawesi

Year: 2026

Type: article

Abstract: Quantitative information on vegetation structure and mangrove regeneration dynamics in the downstream Poso watershed-coastal transition area is limited despite the environmental gradients.Therefore, this study aimed to evaluate mangrove species composition and structural characteristics across growth stages, determine key edaphic and hydrological drivers regulating species distribution, and assess cross-strata spatial patterns to elucidate how micro-habitat filtering influences recruitment and establishment along estuarine environmental gradients in the downstream Poso watershed.Nested transect-plot vegetation sampling was conducted at three stations (Mapane, Bega, and Masani), showing a gradient from the estuary to the open coast.Initial screening evaluated environmental variables including salinity, porosity, organic carbon, and pH; however, after addressing multicollinearity, the final Canonical Correspondence Analysis (CCA) model retained only pore-water salinity and soil porosity as significant environmental drivers of community structure.The results showed that there were 10, 9, and 7 species at the tree, sapling, and seedling stages, respectively.Rhizophora apiculata dominated the tree (Importance Value Index (IVI) = 113.90%)and sapling (IVI = 98.18%) strata, while Ceriops tagal was predominantly found in seedling strata (IVI = 56.60%).Species diversity was classified as moderate across all stages (H′ = 1.603-1.802),while species evenness increased significantly from the tree (J′ = 0.716) to the seedling (J′ = 0.926).CCA ordination (p = 0.004; 81.2% of variance explained) showed that vegetation zonation patterns were controlled by the salinity gradient (Axis 1; r = 0.85) and soil porosity (Axis 2; r = -0.72).This study highlights distinct compositional variations and regeneration patterns across vegetation growth stages along the salinity and substrate gradients.Consequently, simultaneous evaluation of growth stage proved crucial for identifying environmental filtering and formulating precision rehabilitation strategies based on local ecological zonation in estuarine areas.

Source: International Journal of Design & Nature and Ecodynamics

DOI: 10.18280/ijdne.210902