The spruce budworm decision support system: Forest protection planning to sustain long-term wood supply

The Spruce Budworm Decision Support System (SBW DSS) quantifies the margina l timber supply (m(3)/ha) benefits of protecting stands against spruce budw orm (Choristoneura fumiferana (Clem.)) defoliation. It allows the user to q uantify the volume benefit of protecting alternative areas and determine ef fects on forest development and annual allowable cut. Implementing the SBW DSS on a land base involves seven steps: (i) defining the base defoliation, or an explicit forecast of the defoliation level included in yield forecas ts; (ii) compiling historical defoliation; (iii) defining base volume yield s; (iv) obtaining the harvest schedule from the land base management plan; (v) building the stand impact matrix, which quantifies direct impacts of de foliation; (vi) building the forest impact matrix, which quantifies indirec t impacts of defoliation on harvest schedules; and (vii) building the stand -history file, which contains all stand-level and defoliation data. These t asks are usually completed every 5 years. The remaining aspects of the plan ning methodology are implemented annually, including (i) recording the prev ious year's defoliation, (ii) estimating potential defoliation in the curre nt year from budworm survey data, (iii) calculating volume loss or protecti on priority, (iv) generating budworm-caused volume loss maps, (v) digitizin g potential spray blocks, and (vi) evaluating the protection program. Using ARC/INFO and ArcView geographic information system programs, the Protectio n Planning System component (PROPS) generates volume loss maps that can be used to help design and analyze costs and benefits of insecticide spray pro grams. Implementation of PROPS for the 450 000 ha Upper Miramichi Crown Lic ense in New Brunswick is described. Under "normal" and "severe" budworm out break scenarios, defined based on predictions of 1999-2008 defoli ation, lo sses of 6.6 x 10(6) and 16.7 x 10(6) m(3) of spruce (Picea sp.) - balsam fi r (Abies balsamea (L.) Mill.) volume were projected to occur on this land b ase.