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

The role of litter decomposition on organic matter accumulation and nutrient cycling was studied in a floodplain marsh of the Lower Parana River by means 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 laboratory and field experiments. Water fertilization did not significantly affect decomposition rates. Since organic matter production is faster than decomposition a net accumulation takes place in the upper layers of the marsh soil. N and P litter concentration increased during the decomposition experiment. Floodplain marshes represent effective sinks of nutrients through litter accumulation. (C) 2001 Elsevier Science B.V. All rights reserved.