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| ŠUMARSKI LIST 9-10/2023 str. 39 <-- 39 --> PDF |
tree for each type of tree tables are made for a smaller or larger part of the area and for silvicultural systems. The goal of this research was to obtain regression models that can be efficiently used to estimate the merchantable wood volume in high forests (pure and mixed) in the territory of Bosnia and Herzegovina, with a permissible deviation. According to Balić et al. (2020), volume values in the tables as such are not suitable for automated computer data processing, so for these reasons, there is a need to find mathematical models for estimating the tree volume. MATERIAL AND METHODS MATERIJAL I METODE The starting material for the creation of the tables was measurement data of model trees in 2020 and 2021 in different sites and stands conditions. The measurement of model trees was carried out by trained teams composed of forestry workers (chainsaw operator) and forestry engineers. On site, after determining the data that spatially determines the selected tree (Forest management area, forest management unit, compartment, etc.) and measuring diameter at breast height, the tree was felled. After felling, the branches were pruned and sectioned, andthen the measurement of the following parameters was made: the height of the stump, the total length of the trunk, the length of the clean trunk, that is, the length to the beginning of the tree crown (base of the live crown), and the length of the trunk to the spot with a diameter of 7 cm. The trunks were measured by being subdivided into sections (section-wise measurements) with a fixed length of 1.0 m along the entire trunk of the tree, by measuring two mutually perpendicular diameters (di1 and di2) with millimeter precision (over bark). Smalian’s formula was used to determine the volume of the trunk (vtrunk). The volume of the branches (vlarge branches) was determined as the sum of the volumes of individual pieces (vlarge branch) whose volume was determined using simple Huber’s formula (Banković and Pantić 2006; Pranjić and Lukić 1997). Smalian’s formula in this case gives accurate volumes due to the small length of the section. According to Kershaw et al. (2016), Smalian’s formula should not be used unless it is possible to measure sections of the tree in short lengths (maximum lengths of about 1 m). For longer lengths, such as 3 or 6 m, Newton’s or Huber’s formula will give more accurate results. The volume of the top end (vt), that is the last section shorter than one meter, was determined by |