Evaluation of error and efficiency on tree height measurement using Abney’s level, Rangefinder and Vertex IV

Abstract

Tree height is one of the basic variables which is used for estimation of growing stock, biomass, carbon stock and site quality. Measuring tree height is expensive, time-consuming, and error prone due to stand structure and efficiency of measuring instruments. Here, we try to explore the errors and efficiencies associated with Vertex, Abney’s level, and Laser Rangefinder for tree height measurement. Standing tree height was measured using all three instruments and the true height was determined with the careful measurement using linear tape after felling. In total 102 trees of Arunkhola community forest of Nawalpur districts were sampled. It was found that the Vertex (0.55 m) and Abney’s level (2.36 m) overestimated the tree height whereas, Rangefinder (-1.65 m) was underestimating. There was significant difference in errors for all the evaluated instruments at 95% confidence interval. However, there was no relation between true height and DBH with difference in measurement for all instruments. Average time required to measure individual trees was 4.15, 2.29 and 0.93 minutes for Abney’s level, Rangefinder, and Vertex respectively. It was estimated that efficiency for Vertex was 4.46 followed by Rangefinder with 22.69 by reflecting Vertex as the most precise and efficient instrument for measuring tree height.