Determining Harvester Productivity Curves of Thinning Operations in Birch Stands of Central Europe
Author(s)
Date Issued
2022
Type
article
Volume
43
Issue
1
Start Page
1
End Page
12
Abstract
Silver birch (Betula pendula Roth) is a popular tree species forming stands in nearly the whole of Europe. In Poland, birch is one of the most representative broadleaved species growing on rather poor soils, very often as a mix species with Scots pine (Pinus sylvestris L.). In Central Europe, birch forms trunk often with sweep, and at the older age with thick branches. Due to that, a harvester thinning operation in birch stands can be challengeable when trying to process logs from the top part of trees, which can finally impact on productivity. The objective of this research was to determine harvester productivity for birch with particular attention to processing of logs from the top part of a tree. The research was carried out in stands of North and North-West Poland. All together 21 tests were completed in 16 stands, in which 9 harvesters were used (8 different models). The mean diameter of harvested trees was 23.7 cm with the mean height of 21.7 m. Obtained productivity without delays was on average 21.98 m3 h–1 and varied from as low as 5.14 to maximum 44.66 m3 h–1, and depended mainly on harvested tree size. It was also confirmed that top diameter of the last log was related to diameter at breast height (DBH). The model developed based on that relationship can be used for prediction of biomass volume from birch stands when harvesters are used for thinning.
Project(s)
The paper is based on results obtained from the project: The potential of harvester application for hardwood species, EO-2717-22/13, financed by the General Directorate of the State Forests, 2013–2016. The publication was co-financed within the frame work of the Polish Ministry of Science and Higher Education programme: »Regional Initiative Excel lence« in the years 2019–2022, Project No. 005/ RID/2018/19.