Acúmulo e decomposição da serapilheira em quatro formações florestais

Abstract

The aim of this study was to quantify the litter layer on the soil and its decomposition rate, in four different forest types: wild stands of Acacia mangium, Mimosa artemisiana Heringer & Paula and Eucalyptus grandis x Eucalyptus urophylla, and a secondary forest at Fazenda Cachoeirão in the municipality of Além Paraíba, Minas Gerais state. In each forest formation, there were two evaluations, the first one in June 2008 and the second in June 2009, the material was taken to laboratory, where it was separated, oven-dried and weighed. For litter decomposition evaluation, litter bags were used, and those were collected at 30, 60, 90, 150 and 210 days after the installation. In the eucalypt area it was observed the highest litter stock in both evaluations, and the lowest values occurred in mimosa area. The litter of mimosa had the highest rate of decomposition, with values of K = 0.0034 and T1/2= 203 days, while acacia had the lowest (K = 0.0013 and T1/2= 533 days). Among forest stands, mimosa and eucalypt produce faster decomposing litter, which highlights the best efficiency of these species in the process of nutrient cycling and incorporation of organic matter in soil.