Community Structure of Oceanic Mangroves at Marine Tourism Park of Gili Sulat-Lawang, Eastern Lombok, Indonesia

Abstrak

Graphical Abstract Highlight Research 1. The oceanic mangrove ecosystem of Gili Sulat–Lawang shows moderate density and good ecological condition. 2. Twelve mangrove species from eight families were recorded across the study area. 3. Rhizophora mucronata and R. apiculata dominate all stations. 4. Species distribution is strongly influenced by hydrodynamic conditions and sandy substrates. 5. This study provides baseline data for mangrove conservation in small island marine protected areas. Abstract Oceanic mangroves of Gili Sulat–Lawang are strongly influenced by high tidal currents and the absence of river sedimentation, resulting in coarse sediment accumulation. Despite their ecological importance, scientific information on oceanic mangroves in Indonesia remains limited. This study aimed to analyze the community structure and species composition of oceanic mangroves in Gili Sulat–Lawang. Mangroves vegetation data were collected at ten stations across Gili Sulat-Lawang using line transect and quadrat sampling methods. At each station, two 100 m transects were established perpendicular to the coastline, with five 10 × 10 m plots per transect. Community structure was assessed using ecological indices, density, and the Important Value Index (IVI). This study recorded twelve mangroves species in Gili Sulat-Lawang, highlighting the ecological roles of dominant Rhizophora species in oceanic island. The mangroves ecosystem in this area is characterized by a moderate diversity index with high vegetation density. Gili Sulat recorded average densities of 1118 ind/ ha of trees, while Gili Lawang showed a tree density of 1196 ind/ha. Rhizophora mucronata and R. apiculata consistently exhibited the highest IVI values across all vegetation strata. PCA suggested that variation in mangroves community structure was associated with gradients of sediment texture, nutrient availability, and water quality. The dominance of Rhizophora species indicates their strong ecological adaptability in oceanic mangroves environments. This study provides baseline information for mangroves conservation and management on small islands. Further research should focus on long-term monitoring for climate change impacts on mangroves resilience.

Kata kunci

• Gili Sulat
• Gili Lawang
• Community Structure
• Oceanic Mangrove