Distribution, Diversity and Abundance of Mangrove within The Islands of Batam, Karimun, Natuna, and The Surrounding Small Islands

The existence of mangrove forest on small islands is very important in relation to the activity of seawater wave and river flow. The mangrove forests in the islands of Batam, Karimun, Natuna, and the surrounding areas have increasingly been threatened due to port and settlement development. Charcoal industry in some locations continuously exploit the existing mangrove. This study was aimed to determine the distribution, abundance and diversity of mangrove vegetation within the islands of Batam, Karimun, Natuna, and the surronding small islands. A series of 20m x 20m plot were systematically placed along the transects established from the shoreline or riverside into the mangrove forest. The results of spatial analysis using a satellite image showed the distribution of the mangroves spreading along the coastal areas and main river borders. The remaining mangrove forests were still large comprising 10% of each island area in average. The results of the vegetation analysis showed relatively dense populations in each mangrove forest ranging from 1330-2660 individuals/ha. Nevertheless, the diversity of species was commonly very low (the range of the diversity index H'=0.99-1.87) and this seem to be caused by ecosystem disturbances. There were totally 12 species in the study area of mangroves belonging to six families where black mangrove (Rhizophora mucronata) and white mangrove (Rhizophora apiculata) dominated. Prosiding Konservasi Tumbuhan Tropika: Kondisi Terkini dan Tantangan ke Depan. Prosiding Seminar UPT Balai Konservasi Tumbuhan Kebun Raya Cibodas, 7 April 2011. Hal.21-28