Estimating Optimal Thinning and Rotation for Mixed-Species Timber Stands Using a Random Search Algorithm

Steven H. Bullard, Stephen F. Austin State University, Arthur Temple College of Forestry and Agriculture
Hanif D. Sherali
W. David Klemperer

Bullard, S.H., H.D. Sherali, and W.D. Klemperer. 1985. Estimating mixed-species thinning and rotation using a random search algorithm. Forest Science 31(2):303-315.


The problem of optimal density over time for even-aged, mixed-species stands is formulated as a nonlinear-integer programming problem with numbers of trees cut by species and diameter class as decision variables. The model is formulated using a stand-table projection growth model to predict mixed-speciesg rowth and stand-structure. Optimal thinning and final harvest age are estimated simultaneously using heuristic random search algorithms. For sample problems with two species random search methods provide near-optimal cuttings strategies with very little computer time or memory. Optimal solutions are estimated for problems with eight initial species/diameter class groups, projected for up to three discrete growth periods. Such solution methods merit further study for evaluating complex stand- and forest-level decisions