A Long-Term Harvest Scheduling Model Involving Two Types of Rotation and Variable Labour Requirements

摘要

The objectives of this study were to formulate a long-term harvest scheduling model, involving two types of rotation constrained by the available size of the work force, using 0-1 integer programming and then apply the model to plantation forests in the University of Tokyo Chiba Forest as a case study. The following three silvicultural systems were considered: an 80-year and a 160-year rotation clearcutting system and a non-clearcutting system. The minimum amount of labour required to harvest the minimum area was calculated and then that figure was increased to model its effect on harvesting. Subcompartments better suited to timber production tended to be assigned to clearcutting. There was a tendency for subcompartments with a better site class tobe assigned to the shorter rotation and subcompartments with a shorter yarding distance to be assigned to the longer rotation. As the size of the available work force increased, subcompartments less well suited to timber production were also assigned toclearcutting and the harvest volume per person-day and the clear cut area per person-day decreased. The longer rotation was efficient with a smaller work force and the shorter rotation appeared more efficient as the size of the work force increased.