Income and Costs of Forest Cutting in Wood Logging in a Forestry Management Area

RENDIMENTO E CUSTOS DO CORTE FLORESTAL NA EXPLORACAO MADEIREIRA EM AREA DE MANEJO FLORESTAL Avaliou-se a produtividade e os custos da exploracao de madeira na floresta Amazonica, durante a realizacao das operacoes do corte florestal com a motosserra. O estudo foi conduzido em area de manejo florestal, floresta de terra firme, localizada no sul do Estado do Para. Para a determinacao do rendimento foram obtidos os volumes individuais das arvores exploradas e os tempos dos respectivos elementos do ciclo operacional do corte florestal. O custo de producao foi calculado pela razao entre os custos operacionais, fixos e variaveis, pelas horas efetivas trabalhadas. Foi realizada uma analise de correlacao para a verificacao da influencia de propriedades fisicas e mecânicas da madeira no tempo de derrubada das arvores. O ciclo operacional do corte florestal durou em media 31,5 min por arvore processada. As operacoes preliminares consumiram o maior tempo com 45,4% do tempo total, sendo o tempo medio por arvore de 14,3 min. A eficiencia operacional do corte foi de 75% e a produtividade media de 20,15 m 2 he -1 , com custo por hora efetiva trabalhada de US$ 19,36. O custo de producao foi de US$ 1,18 m -3 . As propriedades tecnologicas da madeira nao explicaram estatisticamente as diferencas encontradas nos tempos de derrubada das arvores. Palavras-chave: floresta tropical, Amazonia, motosserra. ABSTRACT The productivity and costs of logging in the Amazon rainforest were evaluated during the performance of the cutting forest operations with the chainsaw. The study was conducted in the forest management, upland forest, located in the south of Para state, Brazil. To determine the income, individual volumes of the exploited trees were obtained and the time of each element of the operational cycle of the forest cutting. The production cost was calculated between the operational costs, fixed and variables by the worked hours. A correlation analysis was performed to verify the influence of physical and mechanical wood properties during the falling of trees. The forest cutting operational cycle lasted an average of 31.5 min per processed tree. Preliminary operations consumed the most time with 45.4% of the total time, with an average time of 14.3 min per tree. The operational efficiency of the cutting was 75% and the average productivity of 20.15 m3 he-1, with a cost of per effectively worked hour of US$ 19.36. The production cost was US$ 1.18 m-3. The technological properties of the wood did not explain statistically the differences found at the time of falling. Keywords: rainforest, Amazon, chainsaw DOI: http://dx.doi.org/10.14583/2318-7670.v04n03a05