DEGRADATION OF MANGROVE LEAF-LITTER UNDER AEROBIC CONDITIONS

Degradation of Avicennia marina (Forsk) Vierh. leaf litter was studied in the laboratory for three months. The leaves were incubated in filtered estuarine water in erlenmeyer flasks for various number of days and the amounts of N, P, and K+ remaining in the leaves determined. Weight loss was rapid within the first 24 hours (19%), but slowed down thereafter reaching 30% after six weeks. While P and K+ decreased with time, N decreased initially, then increased rapidly after six weeks. Leaching and microbial activities could be responsible for the nutrient changes. The increase in N may indicate that mangrove leaf litter provides the surface for microbial N synthesis and acts as a reservoir for N.