Incorporating Regeneration Effort as a Decision Variable in Tactical Harvest Scheduling
Abstract A variable green-up period is incorporated into a tactical harvest scheduling model to allow for the regeneration policy to be included as a decision variable. The benefit of this formulation was demonstrated by solving a 91-logging unit forest plan under four different green-up policies.The first three policies used fixed green-up periods of 2, 3, and 4 years. The fourth policy uses a variable green-up period where the model selects the regeneration effort that determines the green-up period stand by stand. This policy allows each harvested stand to choose among a 2-, 3-,or 4-year green-up period. The variable green-up period resulted in a slight improvement in the net present value because its total was approximately $3,000 or $1.11/ac higher for the total planning area, not just the harvested acres when compared with the best solutions when 4-, 3-, and 2-year fixed green-up periods were used. The variable green-up constraint adds a level of complexity to the spatial harvest scheduling problem that is easily incorporated into a variety of heuristic procedures because they do not require that all combinations of harvest units be specified before solving the problem. The results cannot be generalized to other forests because the spatial arrangement of the stands is a major component in the value determination. However, using the methodology presented, forest managers can evaluate their own alternatives that may improve the returns from managing their resources.