DECOMPOSITION OF LEAF LITTER IN THE BRAZILIAN CERRADO, CERRADÃO AND FOREST ENVIRONMENTS IN THE AMAZON, BRAZIL

Resumo

The soils of the Amazon region, despite being under one of the densest forests in the world, are mostly characterized by low nutrient availability, with litter being the main nutrient input route. The present work aimed to evaluate the litter decomposition in forest, Cerrado and Cerradão environments in the Amazon. The litter decomposition rate was estimated by mass loss analysis using litter bags. The collections were performed at intervals of 30, 60, 90, 120, 150, 180, 210, 240, 270 and 300 days, with four replications. Once collected, the material contained in each litter bag was placed to dry to obtain the dry mass. And so, the remaining mass percentage, the decomposition rates (k) and the half-life time (t_1/2) are estimated. During the studied period, the Cerrado environment presented the lowest constant k (0.0017 g g^-1 day^-1) and consequently longer half-life (407 days). The monthly deposition in Cerrado input ranged from Mgha^-1mother¹ (June to September). Among the evaluated environments, the forest presented the highest decomposition speed and Cerrado presented the lowest one. It was evidenced that the decomposition process for all studied environments occurred with greater intensity in the rainy season.