Effects of measurement errors on an individual tree-based growth projection system

Abstract

Systematic and random measurement errors were placed on the input variables of a distance-independent individual tree-based growth and mortality projection model to study how sensitive the system was to measurement error. The study was conducted in three parts. First, the effects of systematic measurement errors on individual model components of the growth projection were investigated. Second, systematic errors were placed on the input variables of the growth projection system and the performance of the overall system was observed. Third, a Monte Carlo study was performed to examine the effects of random measurement errors of varying magnitude on the projection system estimates. Overall, the projection system was most sensitive to measurement errors in site index. Measurement errors in diameter at breast height were only critical when projecting basal area, but were not critical when projecting number of trees. The system was insensitive to errors in crown ratio.