Productivity and costs in shelterwood harvesting

Harvesting costs have a significant influence on the application and potent ial use of the shelterwood system. These costs are strongly related to the time needed for the logging operations. In this study, which was carried ou t in Norway spruce [Picea abies (L.) Karst.] stands in northern Sweden, the effective time (E-0) of a single-grip harvester in shelterwood cutting, th inning of shelterwoods and clearcutting was measured. Based on these data t he costs of shelterwood harvestings and clearcutting were calculated and co mpared. It was found that (1) the time per tree in shelterwood cutting and thinning of shelterwoods was greater than in clearcutting, (2) the time per cubic metre was higher in sparse shelterwoods than in dense shelterwoods, (3) most of this increase was due to longer driving time because fewer tree s were harvested, and (4) the longer time and higher logging costs in the s helterwood system (compared with the clearcutting system) were mostly relat ed to the establishment of the shelterwood. It was concluded that the shelt erwood alternative is especially competitive when it is desirable to maximi ze the share of saw logs at the expense of pulpwood.