Comparison of an empirical forest growth and yield simulator and a forest gap simulator using actual 30-year growth from two even-aged forests in Kentucky

Abstract

Two individual-tree growth simulators are used to predict the growth and mortality on a 30-year-old forest site and an 80-year-old forest site in eastern Kentucky. The empirical growth and yield model (NE-TWIGS) was developed to simulate short-term (<50 year) forest growth from an industrial perspective. The gap model (ZELIG) is based on the theory of growth processes and has been used to simulate long-term (100 years and greater) forest succession. Based on comparisons of species specific diameter distributions, biomass, and board-foot and cubic-meter volumes, NE-TWIGS performed better for both sites than did ZELIG.