The FVS Model
The Forest Vegetation Simulator (FVS) is an individual-tree, distance-independent growth and yield model. FVS will simulate growth and yield for major forest tree species, forest types, and stand conditions. FVS can also simulate a wide range of silvicultural treatments. Variants of FVS provide growth and yield models for specific geographic areas of the United States.
Prognosis is the original model that became the Forest Vegetation Simulator (Stage 1973). Stage developed Prognosis for use in the Inland Empire area of Idaho and Montana. In the early 1980s, the National Forest Timber Management Staff selected the individual-tree, distance-independent model form as the nationally supported framework for growth and yield modeling. The Timber Staff incorporated the Prognosis modular structure and capabilities into the national model framework. This model framework is the Forest Vegetation Simulator, or FVS.
The Growth and Yield Unit of the Forest Management Service Center (FMSC) in Fort Collins, Colorado, maintains, supports, develops, and provides training for FVS. The FMSC Growth and Yield staff performs a technology transfer role, working with researchers and National Forests staff from various geographical areas to incorporate their findings into the FVS framework.
The FVS model has several components that work together to simulate forest growth and management actions. There are three main growth components of the FVS: a large-tree model, a small-tree model, and an establishment model; and, there is a mortality model. FVS treats a stand as the population unit, using forest inventories or stand examination data. Input files include "keywords" that the user can manipulate to simulate different management scenarios (VanDyck 1999). There are extensions for FVS variants that estimate the influence of other agents upon tree growth, such as insects and disease. Post-processors are other programs that uses FVS output and for further reporting, display, or analysis.
Nicholas L. CrookstonForest Vegetation Simulator Overview and References