Single-tree and Group Selection in Montane Norway Spruce Stands: Factors Influencing Operational Efficiency
Abstract:The operational efficiency of single-tree and group selection with a single-grip harvester was studied in uneven-aged spruce forests at high altitudes in southern Norway. Three harvest intensities of single-tree selection and two group sizes were examined in group selection. Single-tree selection included harvest intensities of 25, 45 and 65% of basal area. Group sizes for group selection were 0.063 and 0.250 ha. Normally, single-tree selection is considered less efficient than group selection or clear-cutting. In this study, because time consumption per cubic metre was primarily dependent upon average harvested tree volume, the large harvested tree size for single-tree selection allowed this treatment to be more efficient than group selection. The two blocks in this study were part of a larger design of five blocks with identical treatments under varying stand conditions. The relative operational efficiency of single-tree selection compared with group selection was greatest in stands of low stocking. Other studies have also shown that mechanical damage to the residual stand is lowest under these conditions.
Document Type: Research Article
Affiliations: 1: Department of Forestry, Danish Forest and Landscape Research Institute, DK-2970 Hørsholm, Denmark 2: Department of Forest Operations, Economics and Products, Norwegian Forest Research Institute, N-1432 Ås, Norway
Publication date: January 1, 2001