Mangrove leaf litter (Excoecaria agallacha) fall and decomposition was estimated using litter bags throughout the year at four sites of Nayachar Island. Excoecaria agallacha is the most common species in Nayachar Island (Latitude 21o 58’ 50’’ N and Longitude 88o 04’ 60’’ E). This species tends to occupy the inner parts of the Island. This study presents the decomposition rate for Excoecaria agallacha leaf litter throughout the year (Premonsoon, monsoon and post monsoon). It also quantifies physico-chemical factors along with the microarthropods population abundance throughout the decomposition process. The result showed that breakdown of leaf litter was season and microarthropods population (Acarina, Collembola, Coleoptera, Hymenoptera, Isopoda etc.) dependent.A significant (P<0.05) higher amount of mass loss, rate of decomposition, decay constant and amount of nutrient return from leaf litter(Excoecaria agallacha) were observed during the post monsoon period.

Keywords : Decomposition, Mangrove, Soil arthropods, Nayachar Island