Humus forms allow the characterization of either a natural forest ecosystem or disturbed forests. Under this perspective, we aimed to identify the humus forms in three Tabuleiro Forest sites in northern Espírito Santo: two primary forests, "Mata Alta" and "Mata de Córrego", and one secondary forest resulting from slash and burn, over 40 years old (Capoeira Queimada). Therefore, the holorganic horizons were studied in regard to the pedological parameters of the mineral soil. At "Mata Alta", a mesotrophic mull was found, characterized by high litter decomposition rates in the holorganic horizon, and by base saturation values around 50-70% in the hemiorganic horizon. The humus profile in "Mata de Córrego" was different from that at "Mata Alta" both due to the higher accumulation in the holorganic horizon, which reflected lower decomposition rates, and soil oligotrophism (V%: 14-35%). These results lead to the classification of the humus form in the "Mata de Córrego" as an oligotrophic mull. In the "Capoeira Queimada", the stock in the holorganic horizons was 2 t ha-1 higher than in the Mata Alta, with sporadic presence of the F2 layer. Nevertheless, regarding the A1 horizon, both the organic matter stocks and the base saturation ratio were lower (30-56%), showing that the carbon and nutrient cycle were not reestablished. The humus form in the "Capoeira Queimada" was classified as an mesotrophic mull.
decomposition; fertility; litter; organic matter; primary forest; secondary forest; soil; tropical forest