PRODUÇÃO E DECOMPOSIÇÃO DE SERAPILHEIRA EM POVOAMENTOS DE TECA NO ESTADO DE MATO GROSSO, BRASIL

Abstract

The objective of this study was to estimate the litter production and decomposition rate, litter renewal and decomposition period in Tectona grandis Linn. F. (Teca) populations. The research was carried out in three different populations located in the city of Nossa Senhora do Livramento – MT state. Litter fall was collected from a limited forest area of 1 (one) ha containing plots with five, six and seven years old, from 20 wood collectors suspended and cast, covering an area of 0,64 m². The accumulated material was collected every 30 days, for 12 months, sent to the laboratory and segregated into leaves, branches (less than one centimeter in diameter) and mixed material, then dried and weighed. The litter fall collected from plots with seven, six and five years old had, respectively, 7,280.25; 6,739.42 and 6,419.61 kg ha -1 . The leaves corresponded to 86% of the deposited litter, branches, 4%, and mixed material, 10%. The decomposition rate constant (K) of the plots with five, six and seven years old were, respectively, 0.54; 0.60 and 0.58. The average time of material renewal per plot, in years, was of 1.84 (671 days) for those with five, 1.67 (609 days) for those with six and 1.71 (624 days) for those with seven years old. The estimated time to decompose 50% of the litter material in the plots consisted in 1.28 years (467 days), 1.15 years (419 days) and 1.19 years (434 days) to the plots with five, six and seven years old, respectively. The estimated time to decompose 95% of the litter fall collected from plots with of five, six and seven years old consisted in 5.53 years (2018 days), 5.00 years (1825 days) and 5.14 years (1876 days), respectively.