Litter Dynamics in Eucalyptus and Native Forest in the Brazilian Cerrado

The aim of this study was to evaluate the litter dynamics in the seasons of the year in three areas: Forest formation Cerradão (CE), and in two hybrids stands of Eucalyptus urophylla × E. grandis with different ages: E1 (34-58 months) and E2 (58-82 months). The produced litter, stored litter and the remaining mass was collected over 720 days. The evaluation of the remaining litter mass in each area was performed from the random distribution of 648 litter bags on the soil. Chemical analyzes (N, P, C) and the structural components of the cell wall (lignin, cellulose and hemicellulose) of the remaining litter were performed. The C of the litter stock was also determined. For both years of evaluation were observed higher biomass and C content in litter at E2. In contrast, the highest decomposition rate was for the CE, especially in the second year of evaluation (mass remaining at 720 days of 35%, 37% and 23% for E1, E2 and CE, respectively), attributed to the higher apparent liberation of N, soil moisture and biodiversity in the native area. Lignin contents increased, cellulose decreased, and hemicellulose remained stable throughout the 720 days. It was also observed an increase in the N and P concentration of the remaining mass and positive correlations among the remaining mass and the C:N and C:P ratios. The C:N ratio of litter was ≥ 76:1 at time 0 and ≥ 30:1 at 720 days for the three areas.