COMPARATIVE ANALYSIS OF TREE DIAMETER MEASUREMENT METHODS

Abstract

Accurate measurement of tree diameter is very important in forestry, when performing various forest works, carrying out various forest inventories, determining the volume and growth of trees. When measuring trees with different measurement methods, different measurement results are obtained, which can be influenced by the type of trees, measurement methodology and measurement direction, and the measurement device used, therefore the purpose of this analysis is to compare and analyze the accuracy, bias, precision of different diameter measurement methods and whether they are statistically different from each other. For this analysis, 400 pine, spruce, beech and aspen trees were measured using four diameter measuring methods: diameter tape, caliper, ruler and visual method. Measurements were made with calipers in two directions and averaged from them. The bias, precision, and accuracy percentage of all measurements were calculated by comparing them to the diameter tape measurements. The results of the analysis showed that there is no statistically significant difference between the different measurement methods in all the selected measured tree species, and the analysis of the bias, precision and accuracy of the different diameter measurement methods showed that the measurements of the caliper had the largest measurement deviations in all tree species, but also the highest measurement accuracy and precision, where the ruler and visual measurement methods had the smallest measurement deviations but also the smallest accuracy and precision of the measurements, but the accuracy and precision of the ruler diameter measurement was closer to the accuracy and precision of the caliper measurements.