PREDICTING REGENERATION ESTABLISHMENT WITH THE PROGNOSIS MODEL

Conifer establishment following regeneration timber harvests is predic ted by version 2 of the Regeneration Establishment Model, a submodel o f the Prognosis Model. The regeneration model covers 10 species for fo rests in Montana, central Idaho, and northern Idaho. Most harvest and site preparation methods can be simulated so that alternative treatmen ts can be evaluated. Also included in the model is the influence of we stern spruce budworm (Choristoneura oocidentalis) on regeneration succ ess. The model predicts the probability of stocking, seedling density, species composition, and seedling heights 2 to 20 years after harvest . This paper describes the study design, equation development, model f ormulation, and model behavior for the Regeneration Establishment Mode l.