Interactive clear-cut regime selection for risk management of wind damage using reference point approach

This study integrated two different reference point approaches, VIMDA and LBS, into the geographical information system software with a forest growth and yield model and a mechanistic wind damage model. The main aim was to compare the performance of these two reference point approaches in interactive search of the most appropriate clear-cut schedules and patterns in regard to the objective set for risk management of wind damage and timber production. For this purpose, we first simulated growth dynamics of forest stands over 30 years in a forest management unit located in central Finland, using at maximum four alternative treatment schedules for each stand (i.e. clear-cut made in 5th, 15th, and 25th year or not at all). VIMDA and LBS were thereafter used to solve two different planning problems: (1) minimizing the risk of wind damage with maximizing timber harvest; and (2) minimizing the risk of wind damage with even-flow timber harvesting objectives, based on 400 randomly generated clear-cut alternatives at landscape level.Both VIMDA and LBS did output similarly rational solutions for both planning problems. When aiming at minimizing the risk of damage in terms of length of vulnerable edges, some clear-cuts were clustered in both planning problems. However, the objective of timber harvest limited the possibility to decrease the risk of wind damage. Furthermore, both VIMDA and LBS are sensitive to the changes of the aspiration level. Incomparable aspiration level could produce incomparable solutions to approximate their own goals. Although the final output of VIMDA and LBS may not be globally optimal, their final solutions could be expected to fulfill objectives defined by the decision maker.