Keanekaragaman Vegetasi Mangrove dan Permudaan Alaminya di Area Tracking Mangrove Pulau Kemujan Taman Nasional Karimunjawa

Mangroves serve as important habitat for many species of aquatic biota, i.e. fish, molluscs, and crustaceans. This ecosystem also acts as sediment trap; protecting adjoining coral reef systems. A field survey was conducted to analyze the structure and diversity of mangrove vegetation and mangrove regeneration levels in the tracking area at Kemujan Island, Karimunjawa National Park. Data collection were using surveymethodandobservation. The primary data collected includings density, frequency, and dominance of mangrovetree species; as well as the substrate composition; taken by quadrat method arranged on a line transect. A total of 16 sample plots were taken in two line transects, laid in the field accroding to systematic sampling with random start. The data collected were analyzed by important value index. As a result, there were 730 individuals of mangrove tree species in various growth-stage, counted in such sample plots, consisting of 10 species: Bruguiera cylindrica, Ceriops tagal, Excoecaria agallocha, Lumnitzera littorea, L. racemosa, Rhizophora stylosa, R. apiculata, R. mucronata, Scyphiphora hydrophyllacea, and Sonneratia alba. Among them, Ceriops tagal has the highest important value index (IVI) at the level of seedlings (126.26%); and saplings (121.07%). At the tree level there’s Lumnitzera racemosa domination (117.82%). Type of substrate is dominated by sand 79.32% with a range from 71.16 to 95.02%; dust 13.20% with a range from 3.61 to 17.54%; clay 7.49% with a range from 1.37 to 12.48%. The composition of the substrate affects the dominant mangrove species, namely Ceriops tagal and Lumnitzera racemosa