A density-dependent stand-level optimization approach for deriving management prescriptions for interior northwest (USA) landscapes

Abstract

Stand-level forest management prescriptions for federal forests in the interior northwest (USA) have changed emphasis in the past decade from being influenced by economic criteria to being influenced by ecological criteria. The design of forest management prescriptions that maintain stand density levels within a target range is now preferred over the design of prescriptions that maximize net present value. We describe a stand-level optimization process for developing efficient management regimes that uses dynamic programming and a region-limited search strategy. The process develops management regimes by penalizing deviations from a preferred range of stand density. Operational considerations, such as minimum harvest levels, can be important, and are considered as constraints in this modeling process. The timing of harvests is such that entries are only permitted when a minimum harvest can be obtained, when a minimum residual basal area can be maintained, and when harvests are limited to trees with a certain diameter range. Lists of residual, harvested, and dead tree records are available for each decade of the optimal regime. These records of information can facilitate further forest product or habitat suitability analysis associated with forest policy analyses.