LITTER FALL AND DECOMPOSITION OF MANGROVE SPECIES AVICENNIA MARINA IN SURABAYA EAST COAST, INDONESIA

The mangrove ecosystem is supported by leaf litter production and decomposition that accompanied the release of nutrients in system and adjacent coastal water. The release of nutrients in the form of nitrogen and phosphorus have an important role to enrich the nutritional content and is beneficial for marine organisms. In present study litter production, rate of leaf decomposition and release of nutrient (nitrogen and phosphorus) in mangrove habitat at Surabaya East Coast, Java, Indonesia were studied. The result showed total mangrove litter production (dry weight) ranged between around 2.15 to 3.28 g/m2/day. Among them leaf litter was the major contributor (76.26% -78.53%) followed by branches (9.43-13.27%), and reproductive parts (8.20-14, 31%). Mangrove forests in Surabaya East Coast are the result of reforestation with an area of approximately 345.6 ha which potentialy contribute nitrogen and phosphorus (109.43 to 173.549 kg/ha/year) and (5.467 to 8.12 kg/h/year), respectively. Variations in litter decomposition indicate fluctuations input of nutrients that are important for mangrove ecosystems.