A Risk Discounting Model for Forest Growth and Yield

Tree growth and yield are important parameters for management of forests. Forest disturbance is included in many landscape studies but not in stand growth and yield models because badly damaged or destroyed stands are not part of model calibration data. To help account for this, a risk discounting method is developed based on hazard functions. Because stands that are destroyed are replanted, the entire yield from that stand is not lost but is only delayed by the age of the stand when destroyed. This means that the discount coefficient for age-independent disturbances is roughly half the empirical landscape disturbance rate, as verified by simulation of even-aged managed forest. Disturbances such as planting failure that only destroy the youngest stands have a very small discount rate compared to landscape disturbance data because few years of growth are lost in these cases. If only the oldest stands are subject to destruction, the discounting function underestimates yield reduction for high levels of disturbance. Including risk allows a more realistic assessment of expected yield under uncertainty. Discounted yields can be used to assess adequacy of wood supply for a mill or as input for an economic analysis.

Cite this article as: Loehle, C. (2026). A risk discounting model for forest growth and yield. Forestist, 76, 0128, doi: 10.5152/forestist.2026.25128.