Leaf packs of the aquatic macrophyte Eichhornia azurea were used to experimentally evaluate changes in mass, carbon, nitrogen, and phosphorus concentrations, and C:N ratios during initial stages of decomposition in two different environments, the Paraná River and Garças Lake. Analysis of weight loss showed relatively slow decomposition rates in both environments (0.0047 d-1 and 0.0048 d-1 respectively). Over a 45-day period we observed significant changes (p < 0.05) in concentrations of carbon, nitrogen, and phosphorus, but only carbon differed between the environments (F = 10.479; p = 0.03). Therefore we concluded that detritus behaved similarly during decomposition, since intrinsic characteristics of the environments affected only the carbon concentrations.
Eichhornia azurea; decomposition; floodplain; Paraná river
