Impacts of the time horizon for adjacency constraints in harvest scheduling

Adjacency constraints, constraints which limit the harvest timings of adjac ent management units, are a challenge to address within forest management s cheduling models. Four large test cases were examined to consider the need to recognize site-specific adjacency constraints over a long time horizon w ithin a forest management scheduling model. Results suggest that the costs of adjacency constraints tend to be short-term in nature. Immediate periods tend to be influenced most because there is less lead time to prepare for the constraints. Little may be gained in planning by addressing adjacency c onstraints for more than a full rotation length. Adjacency constraints can likely be satisfied efficiently without having large shifts in harvest timi ngs for most all management units. Results are consistent with an interpret ation of the dual formulation of a relaxed linear programming formulation o f the problem.