The remaining black jewels ecosystem in southern Peninsular Malaysia: Floristic composition of peat swamp forest in Muar, Johor

Abstract The Ayer Hitam North Forest Reserve (AHNFR) is located in the Muar district of Johor, Malaysia. The total area of AHNFR is stated as 3,797 hectares (ha), and this forest is unique as it has both inland forest and peat swamp forest. Peat swamp forest established on organic soils while the inland forest grows on mineral soils. AHNFR best described as the last remaining ‘black jewel’ ecosystem in the state of Johor as other peat swamp forests has perished. Five transect lines were established within the peat swamp forest areas. Each transect line has five plots where each plot is 0.04 ha in size. All trees with more than 10 cm in diameter at breast height were enumerated to determine the community structure and diversity of trees. 447 individuals tree were enumerated and result indicated that a total of 31 families with 70 species were found in the area assessed. The total tree density for peat swamp forest in AHNFR was estimated at 447 tree ha-1. The top five species with highest density were Syzygium cerinum (33 tree ha-1), Syzygium inophyllum (31 tree ha-1), Palaquium hexandrum (29 tree ha-1), Stemonurus secundiflorus (24 tree ha-1) and Koompassia malaccensis (21 tree ha-1). Total tree basal area at peat swamp forest area of AHNFR was 24.48 m2ha-1. Species with highest basal area was K. malaccensis (3.46 m2ha-1) while the least was Lithocarpus curtisii (0.01 m2ha-1).