Abstract:

Objective: The effects of reversion search strategy on improving the performance of simulated annealing algorithm were quantificationally evaluated,which could provide some new insights into solving the complex forest planning problems. Method: The reversion search process were estimated based on the 1-opt and 2-opt moves of simulated annealing,and then were applied into a large and real forest planning in Pangu forest farm in the northeastern part of China. The objective function of the planning problem focused on the needs for an even flow of harvest volume. A special strategy was employed to deal with the spatial and temporal distribution of forest management activities,in which the forest tending prescriptions complied with the unit restriction model of adjacency constraints,however the clear-cutting prescription complied with the area restriction model of adjacency constraints. In addition,both adjacency models should meet 3-yrs green-up constraints. Result: The results indicated that the number of reversions between 1-opt and 2-opt moves usually had no significant effects on the planning results. For a minimization planning problem,the mean objective function values of reversion search decreased significantly when compared that with 1-opt (P < 0.01) and 2-opt (P < 0.01) moves,respectively,however,the mean computation time of reversion search was only as large as five and two times than that of 1-opt and 2-opt moves,respectively. The optimal solution indicated that the amount of assigned harvest timber during an entire planning horizon were approximately 5.00×10⁵ m³,in which the levels of harvest timber using different forest tending prescriptions were 3.12×10⁵ m³,and the levels of harvest timber using clear-cutting prescription were 1.88×10⁵ m³,the assigned harvest area of forest tending and clear-cutting only accounted for approximately 10.94% and 1.02% of the total forest area,respectively. Therefore,the optimal solution from this study could meet the requirements of sustainable forest management. Conclusion: Reversion search is one of the most efficient and stable strategy to improve the search ability of heuristics,which could adapt to the complex forest management planning,and then provide some technical supports for making approximate forest management plans in future.

Key words: simulated annealing, reversion search, management planning, adjacency constraints, green-up constraints