The Forest Vegetation Simulator (FVS) is a family of models used for predicting forest stand dynamics (tree growth, mortality, regeneration, management, disturbance, etc.) throughout the United States. The Forest Health Assessment and Applied Sciences Team supports a variety of insect and pathogen models that allow FVS users to incorporate forest pest disturbances into their FVS projections.
The family of FVS models comprises 20 different geographic variants, each calibrated to local conditions. Insect and disease models for FVS are developed and maintained in partnership with Forest Health Protection and the Forest Management Service Center. The models take one of two forms: (1) FVS model extensions, which are integrated into and interact directly with the base FVS model, or (2) keyword component (kcp) files, which contain FVS keywords instructing the base FVS model to perform specific calculations and activities (such as mortality) during a simulation. Availability of insect and disease models varies by FVS variant, as summarized below.

Image represents a stand of Douglas-fir in the Fremont National Forest as simulated with the South Central Oregon Northeastern California variant of the Forest Vegetation Simulator (FVS) and the Dwarf Mistletoe Model. View animation (Opens in new window/tab)