GROWTH RATE OF TREE SPECIES IN A TERRA FIRME NATURAL FOREST AFTER LOGGING AND SILVICULTURAL TREATMENTS, IN THE MUNICIPALITY OF PARAGOMINAS, PAR\uc1, BRAZIL

Abstract

Este trabalho teve como objetivo avaliar os efeitos de tratamentos silviculturais sobre o crescimento de uma floresta natural de terra firme explorada usando t\ue9cnicas de impacto reduzido. A pesquisa foi conduzida na \uc1rea de Manejo Florestal (AMF) da Fazenda Rio Capim, pertencente \ue0 empresa Cikel Brasil Verde Madeiras Ltda., localizada no munic\uedpio de Paragominas, Estado do Par\ue1. A \ue1rea experimental correspondeu a 500 ha, nos quais foram estabelecidos cinco tratamentos (100 ha cada) com quatro repeti\ue7\uf5es (25 ha cada) seguindo um delineamento completamente ao acaso. As repeti\ue7\uf5es foram distribu\ueddas aleatoriamente na amostra de 500 ha na AMF. Foram avaliados os seguintes tratamentos: T1 \u2013 explora\ue7\ue3o de impacto reduzido (EIR) + desbaste de libera\ue7\ue3o cl\ue1ssico e corte de cip\uf3s; T2 \u2013 EIR + desbaste de libera\ue7\ue3o modificado e corte de cip\uf3s; T3 \u2013 EIR + corte de cip\uf3s; T6 \u2013 apenas EIR; T7 - floresta n\ue3o explorada (testemunha). Nos quatro anos de monitoramento da floresta, ap\uf3s a colheita de madeira e aplica\ue7\ue3o dos tratamentos silviculturais, T2 e T3 tiveram as maiores taxas de crescimento em di\ue2metro. Contudo, o per\uedodo de quatro anos n\ue3o \ue9 suficiente para indicar o tratamento \u201cmais adequado\u201d, com base no crescimento em di\ue2metro, em resposta \ue0 anelagem de \ue1rvores e corte de cip\uf3s. Em n\uedvel de esp\ue9cie, o crescimento variou entre e dentro dos tratamentos experimentais. Em geral, as menores taxas de crescimento em di\ue2metro ocorreram na floresta n\ue3o explorada (T7).This paper deals with the effects of silvicultural treatments on growth rates of a terra firme natural forest after reduced impact logging (RIL). The study was carried out in the Rio Capim Forest Management Unit, which belongs to Cikel Brasil Verde Madeiras Ltda., located in the municipality of Paragominas, PA. The experimental area comprised 500 ha, where five treatments (100 ha each) each with four replications (25 ha each) were established. The replications were randomly distributed in the 500 ha sample area. The following treatments were applied: T1 \u2013 RIL + classical liberation thinning (girdling of competing trees) and climber cutting; T2 \u2013 RIL + modified liberation thinning (girdling of competing trees) and climber cutting; T3 \u2013 RIL + climber cutting; T6 - only RIL; T7 - unlogged forest (control). In the four years of monitoring forest, after logging and silvicultural treatments, T2 and T3 had the highest diameter growth rates. But the four-year period is not enough to suggest the best treatment, based on diameter growth rate, in response to girdling trees and climber cutting. At species level, growth rate varied between treatments and within treatments. In general, the lower diameter growth rates were observed in the unlogged forest