Designing the mechanized first thinning in a pine stand: assessment of productivity, costs and tree damage. Issue 3 (2nd September 2021)

• Record Type: Journal Article
• Authors: Berude, Leandro C.; Fiedler, Nilton C.; Lopes, Eduardo S.; Rodrigues, Carla K.; Nadolny, Alana; Pelissari, Allan Libanio
• Is Part Of: International journal of forest engineering. Volume 32:Issue 3(2021)
• Page Start: 216
• Page End: 223
• Publication Date: 2021-09-02
• Subjects: Commercial thinning -- planning -- Pinus taeda -- strip roads -- wood harvesting; Forestry engineering -- Periodicals; Génie forestier -- Périodiques; Forestry engineering; Periodicals; 634.905
• DOI: 10.1080/14942119.2021.1908748
• Languages: English
• ISSNs: 1913-2220

Abstract

ABSTRACT: The aim of this study was to evaluate the productivity, costs, and tree damage caused by machines in first thinning operations. The study was carried out in a 10 year old pine stand with two thinning operations: TH5, with the removal of each 5 th row and selective thinning between these rows; and TH7, with the removal of each 7 th row and selective thinning between these rows. Harvester and forwarder machines were used in the thinning operations, considering a tree maximum reach of 10 m. Working cycle times, productivity, energy efficiency and production costs were determined through a time–motion study. The tree damage was also quantified in the thinning operations. Cycle time values and tree damage were compared using the Mann–Whitney test for two independent samples (α = 0.05). The highest productivity and lowest cost for the harvester were observed in TH5, while the highest productivity for the forwarder was obtained in TH7, due to the higher log stack volume. On the other hand, TH5 was the most inexpensive operation, with a total of USD$4.62 m −3, although only USD$0.37 less expensive than TH7. Furthermore, TH5 and TH7 presented a similar percentage of tree damage of 20.9% and 19.1%, respectively. Therefore, TH5 was most cost-effective, while TH7 enables increasing the selective thinning area and improves the pine stand quality.