Análise técnica e de custos do corte florestal semimecanizado em povoamentos de eucalipto em diferentes espaçamentos

Abstract

RESUMO:Objetivou-se, com este trabalho, avaliar, tecnicamente, os custos do corte florestal semimecanizado, em plantios de eucalipto de primeira rotação, em declividade média de 26,22° (58,2%), nos espaçamentos 3 x 2,5 m, 3 x 3,33 m e 3 x 4 m, com volumes de 0,326, 0,361 e 0,370 m 3 por árvore, no sistema 1+1 (um operador de motosserra e um ajudante). Os resultados mostraram que as atividades que consomem mais tempo no corte e processamento com a motosserra Stihl MS360 são: deslocamento, traçamento e 1º, 2º e 3º corte. No espaçamento 3 x 2,5 m, a produtividade média foi de 4,69 m 3 . h . O item de maior influência nos custos operacionais foi a mão de obra, com 75 % dos custos totais. O espaçamento maior resultou em maior produtividade e menores custos de produção. TECHNICAL AND ECONOMIC ANALYSIS OF SEMIMECHANIZED HARVEST OF EUCALYPTUS IN DIFFERENT SPACINGABSTRACT: The objective of this study was to evaluate technically semi-mechanized forest cutting costs in eucalypt plantations in first rotation, average slope of 26.22° (58.2%), spacing 3 x 2.5 m, 3 x 3.33 m and 3 x 4 m, with volumes of 0,326, 0,361 and 0,370 m 3 per tree, in the 1+1 system (one chainsaw operator and a helper). The results showed that the activities that consume more time in cutting and processing with the chainsaw Stihl MS360 are: displacement, bucking and 1st, 2nd and 3rd cut. Spaced at 3 x 2.5 m, average productivity of was 4.69 m 3 . h -1 at a production cost of 5.16 R$ . m -3 . In the 3 x 3.33 m spacing average productivity was 5.19 m 3 . h -1 and 4.66 R$ . m -3 and in the 3 x 4 m spacing was 5.73 m 3 . h -1 and 4.22 R$ . m -3 . The item of greatest influence on operating costs was labor, with 75% of total costs. The wider spacing resulted in higher productivity and lower production costs.

Performance of a whole tree mechanised timber harvesting system when clear-felling a 32-year-old Pinus taeda L. stand

“…Under conditions of lower mean tree individual volume, Pereira et al (2015) reported slightly higher values of P PMH for tree felling with a tracked feller buncher than those observed in the present study and lower values for extraction activity with wheeled skidder. The operational performance for manually processing large logs with a chainsaw (Table 2) was similar to that found by Leite et al (2014), although the latter study was conducted in eucalyptus plantations with lower mean individual-tree volume. The P PMH of processing medium size logs with the mechanical slasher was higher than the value reported by Conrad IV and Dahlen (2019) and the P PMH of processing small logs with the excavator-based harvester was also higher compared with that reported by Ghaffariyan et al (2012) andScorupski et al (2017), however, the operational conditions of these studies were different.…”

Costs of semi-mechanized forest harvest of Tectona grandis L. F. in the brazilian Amazon

“…In absolute values, gross profit per hectare was approximately R$ 15,525.00, of which 30.76% was charged by operating costs, being the labor costs the most significant. Leite et al (2014), analyzing the costs of semi-mechanized forest felling in eucalyptus stands with different spacing also found similar values of 75% in labor costs. Vargas (2019), in an analysis of final cutting of Pinus elliottii in two relief operation conditions, found out similar values in labor costs in operations of felling and bucking in the forest stand, 57% and 65% respectively.…”

“…The semi-mechanized harvest is that carried out with chainsaws, a method still employed in small medium forest companies, which demands large numbers of workers (MASIOLI et al, 2020). The semi-mechanized method uses the chainsaw to execute the steps of felling, delimbing, stump removal and bucking of the wood, with a low operating cost, being able to cut and process the trees in any type of terrain (LEITE et al, 2014). The main advantages are the low acquisition cost of the machinery, performance in any topographic condition and high productivity compared to the manual method.…”

Análise técnica do corte semimecanizado do Angico (Anadenanthera colubrina (Vell.) Brenan)

“…Outros fatores que podem ter influenciado nos tempos, são a inexperiência do operador da motosserra na realização do corte, relatado por Chaves (2016), como sendo esta a maior dificuldade encontrada para a realização da atividade de corte; e "enganchamento" da motosserra, citado por Pereira et al (2012), em uma avaliação da segurança e ocorrência de defeitos na operação de corte semimecanizado de florestas de eucalipto, como um dos aspectos que resultou em elevado tempo na maioria dos tratamentos. Leite et al (2014), cita o espaçamento da vegetação como um dos fatores que influenciam no aumento do tempo da atividade corte, pois havendo dificuldade de acesso aos indivíduos, menor espaçamento, exigirá maior tempo para execução das atividades.…”