Sustentabilidade da produção madeireira de Goupia glabra Aubl. (cupiúba) na Amazônia brasileira.

Abstract

The sustainability of the production of timber in natural forests is a subject matter of great discussion. The concern to have perpetuity in the forest production, mainly of species of value in the market, is a challenge for the management of natural forests. This research was developed with the objective of analyzing the dynamics of growth in six experimental areas of forest management monitored in the Brazilian Amazon and discuss the ability of the species to recover in 35 years, in order to subsidize strategies for sustainable forest management. To compose this study, we used data from a continuous forest inventory of six experimental areas of the Network of Monitoring of the Dynamics of Forest in the Amazon. – Redeflor, monitored by Embrapa Amazônia Oriental and Embrapa Amazônia Ocidental, located in three states of the Brazilian Amazon: State of Pará (n = 4), State of Amapá (n = 1) and State of Amazonas (n = 2). In the study, the parameters were analyzed: density of trees (arv.ha-1), basal area (m².ha-1), mortality (arv.ha-1 and %.year-1), recruitment (arv.ha-1 and %.year-1) and periodic annual increment in diameter (IPAd). With the parameters of dynamics analyzed, obtained the rate of recovery of the trees (%.arv) with DBH ≥ 20 cm capable of reaching the minimum diameter allowed by the current law (DBH ≥ 50 cm), in 35 years. The trees of G. glabra with DBH ≥ 20 cm presented a natural density distinct between the areas, with variation of 0,8 to 5,5 arv.ha-1, occupying a basal area of 0,343 to 1,814 m².ha-1. The dynamics of mortality and recruitment, after 31 years of monitoring, evidenced that the species did not recover the density and dominance after the harvest. The IPAd, between monitored sites, varied of 0,19±0,27 to 0,93±0,55 cm.ano-1, in which the smaller diameter trees (DBH 20-49,9 cm) presented the rates highest of growth. The recovery of the stock of trees with DBH ≥ 50 cm was on average 28%, although was observed a high variation among the managed areas. The estimate of a tree with a diameter of 20 cm to reach the cutting diameter (DBH ≥ 50 cm) needs approximately 83 years. The verification of the non-recovery of the original stock of trees of G. glabra, in 35 years, requires a different management of the pattern, with a longer interval between harvests, considering the dynamics of growth of the species in the managed area.