To increase biomass volume production harvesting should enable the mechanization in hilly areas, but lacks scientific studies to assess the operation. The harvesting in areas inclined are adopted chainsaw and aerial cables which require high production costs and offer high physical exertion and danger. The harvester and forwarder introduction on the exploitation of biomass in these areas aim to reduce costs, regulate biomass production and offer better working conditions. The work aimed to evaluating the performance of the modeling of a mechanized harvesting system of cut-to-length in eucalyptus forest. The modeling of the harvester and forwarder under conditions consisted declivity up to 36 °, 0.132 to 0.423 wood volume by tree and extraction distances up to 470 m, operating in three shifts 6 m length in tracing. The modeling use allowed determining the logging and extraction machines operational performances in the cut-to-length system. Modeling showed that increased terrain declivity, increased extraction distance and reduced of wood volume by tree decreased the machines productivity. The adoption of the winch by machines allowed to extract biomass on slopes which suggests the adoption of mechanized system and benefits to employees of the ergonomic point of view.

Keywords: harvester, forwarder, cutting, extraction.