Decomposition of Mangrove Litters and The Effect On The Carbon:Nitrogen Ratio In A Tropical Mangrove Ecosystem
The in situ decomposition of litters of Rhizophora racemosa were monitored in mangrove sediment along Calabar river, Nigeria In the study area mangrove detrital material were buried and incubate in the litter-boxes in the sediment for 60 days and the in organic carbon and nitrogen were monitored. The exchange of oxygen, dissolved organic carbon (DOC), carbon dioxide and inorganic nitrogen at the sediment-water interface was measure throughout the incubation period. After 60 days incubation 64.5% of the leaf litter were decomposed suggesting that longer incubation period will be needed for the decomposition of refractory fractions. There was no appreciable increase in sediment oxygen uptake (SOU) in the sediment. However an increase in DOC was noticed with 45 days, thus serving as an important link between mangrove and the adjoining water bodies. A decrease of C:N ratios was noticed in the sediment and was attributed to microbial activities at the sediment-water interface. Nitrogen in the sediment was highly immobilized and unavailable for uptake in the overlaying water.