Mangrove diversity, stand structure, and distribution across four coastal ecosystem types in Peninsular Malaysia

Abstract

A study on mangrove structure and species diversity was carried out across six sites in Peninsular Malaysia, representing four types of coastal habitats: islands (Pulau Korea, Pulau Burong, and Pulau Merambong), nearshore island (Pulau Kamat), open coast-riverine (Tanjung Pelepas), and inland lagoon (Pengkalan Nangka), consisting of naturally occurring mangrove stands. Comparative ecological assessments across different coastal habitats are limited in Peninsular Malaysia, especially for island-associated mangrove systems. This study aimed to examine mangrove species diversity, stand structure, and environmental relationships across these habitats. Using a systematic plot-based method (25 m × 25 m), 19 true mangrove species were recorded, with the highest species richness of 13 at Pulau Merambong and Tanjung pelepas. Avicennia alba was found at all sites. The Shannon-Wiener’s diversity index (H) ranged from 1.235 to 2.888. The mean diameter at breast height (DBH) significantly varied among sites (p ' 0.05), with the largest trees observed at Pengkalan Nangka lagoon and the smallest at Tanjung Pelepas. Dominant species varied by location, with Bruguiera cylindrica at Pulau Korea, Sonneratia alba at Pulau Burong, Pulau Kamat, and Pulau Merambong, and Avicennia marina at Tanjung Pelepas and Pengkalan Nangka lagoon. Pearson network correlation analysis (PNCA) revealed very high negative correlations between Simpson’s index (D) and sand fraction (r = -0.905), and between H and D (r = -0.922, p ' 0.05). High positive correlations were observed between sand fraction and H (r = 0.865, p ' 0.05) and water salinity and soil pH (r = 0.780, p ' 0.05). Additionally, a high negative correlation existed between DBH and soil pH (r = -0.754, p ' 0.05), and between DBH and water salinity (r = -0.723, p ' 0.05). Overall, these findings highlight differences in mangrove diversity and stand structure across various coastal habitats and provide a comparative ecological perspective on mangrove community patterns in tropical coastal environments.