EFECTO DEL SUSTRATO SOBRE LA DESCOMPOSICIóN DE HOJARASCA EN TRES ESPECIES DE MANGLE EN LA RESERVA DE BIOSFERA SEAFLOWER, CARIBE COLOMBIANO

the presence of mangroves in small caribbean islands such as providencia and santa catalina is important because they act as a barrier against sporadic storms and hurricanes. mangroves, in turns, require the input of sediments for their maintenance and growth. in absence of allochthonous sources, the sediment supply in these islands is acquired by the mangrove’s leaf decomposition. the main purpose of this study was to quantify the rate of leaf decomposition in three mangrove species in the most representative island`s wetlands, in different decomposition substrates: water, peat and forest surface. the decomposition rate in each site was faster during the first three weeks, where the highest biomass lost was registered, followed by a slow decomposition period that continued until the end of the sampling period. the exponential model, calculated with the remaining weight data along the 11 experimentation weeks, showed the better adjustment to the decomposition dynamic. the repeated measurements anova showed significant differences among species; leafs of rhizophora mangle decomposed at a slower rate (k = 0.020 ±0.007) than those of avicennia germinans and laguncularia racemosa (k = 0.021 ±0.01; k = 0.022 ±0.006, respectively). these decomposition rates provide valuable information about circulation of vegetal material in each studied mangrove and the contribution of species to the environment.