SURVIVAL MODEL FOR PINUS-SYLVESTRIS SEEDLINGS AT RISK FROM HYLOBIUS-ABIETIS

Survival of pine seedlings was studied in a planting trial with special attention paid to damage caused by the pine weevil. The seedlings were checked individually at ten different instances during the five-year period following planting. The survival data and seedling characteristics were fitted to the nonparametric Cox proportional hazard model. The proportional hazard model is apparently useful in forest regeneration studies, both in analyzing changes in the seedling survival rates, and in predicting consequent survival probabilities over continuous time.