Litter decomposition of emergent macrophytes in a floodplain marsh of the Lower Parana River

The role of litter decomposition on organic matter accumulation and nutrien t cycling was studied in a floodplain marsh of the Lower Parana River by me ans of in situ litterbag experiments. The effect of waterborne nutrients on decomposition rates was studied through a laboratory litterbag experiment. Litter decomposition was rather slow remaining 40-50% of the initial mass after 2 years incubation. Similar decomposition rates were observed in labo ratory and field experiments. Water fertilization did not significantly aff ect decomposition rates. Since organic matter production is faster than dec omposition a net accumulation takes place in the upper layers of the marsh soil. N and P litter concentration increased during the decomposition exper iment. Floodplain marshes represent effective sinks of nutrients through li tter accumulation. (C) 2001 Elsevier Science B.V. All rights reserved.