Dynamics of phosphorus and nitrogen through litter fall and decomposition in a tropical mangrove forest

Distribution, dynamics and mass budget of phosphorus and nitrogen in a red mangrove forest were studied in the Potengi mangrove forest in northern Brazil (lat. 5°42′ and 5°53′ S, long. 35°5′ and 35°25′ W). Tidal hydrology, net primary productivity, leaf litter decomposition rate and standing stock of leaf litter in a red mangrove forest were measured. The results showed that the main reservoir for total P and total N was the sediment with 309 kg ha−1 and 4619 kg ha−1 (77% and 95% of the total P and N content in the mangrove forest), respectively, for the two elements. Total P and total N in Rhizophora mangle trees accounted for 145 ± 14 kg ha−1 and 216 ± 23 kg ha−1 (23% and 5% of the total P and N in the mangrove forest). The estimated average export rates for P and N through leaf litter are 0.5 kg ha−1 yr−1 and 1.6 kg ha−1 yr−1 respectively. Our measurements support previous results in concluding that mangrove forests efficiently retain P and N.