Assessing harvesting productivity and fuel efficiency in secondary Nothofagus antarctica forest management in Northern Patagonia

Abstract

Forestry science has generated extensive knowledge about the operational aspects of forest harvesting machinery in industrial plantations. However, less knowledge is available for native forestry settings, particularly in developing countries. To address this, astrip cutting field experiment, with chainsaw, was conducted to assess the impact of stand structure on harvesting productivity (m3 /h) and fuel efficiency (m3 /l) in 12 contrasting plots of secondary Nothofagus antarctica forests in Northern Patagonia, Argentina. Additionally, the work days and fuel consumption necessary for strip cutting 1 ha was calculated. Harvesting productivity and fuel efficiency were highly correlated, and both increased with the total volume and dominant height of the stands but decreased with tree stand density. When the total volume increased from the minimum to the maximum value of the range (5.5 m3 /ha to 244.2 m3 /ha), productivity increased by 540% and fuel efficiency by 460%, and when the dominant height increased from the minimum to the maximum value of the range (2.05 m to 6.95 m), productivity increased by 560% and fuel efficiency by 440%. In terms of work days and fuel consumption, stands with a dominant height of 2.05 m required 9.3 work days (8 h/day) and 21.1 l fuel per hectare, while stands with a dominant height of 6.95 m required 51.7 work days (8 h/day) and 147.6 l fuel per hectare. Overall, this study’s findings highlight that greater operational efficiency is achieved in stands with higher volumes. Furthermore, dominant height serves as an easily measurable proxy for labor and fuel requirements, contributing to the feasibility analysis of projects in N. antarctica secondary forests and similar ecosystems globally.