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| ŠUMARSKI LIST 9-10/2023 str. 38 <-- 38 --> PDF |
in Bavaria, but also in other parts of Germany and neighboring countries. From that time, the wider application of volume tables in forestry practice begins. The Association of German Forest Research Institutes adopted a plan on the basis of which new tables were created, starting from model trees felled throughout the whole of Germany in pure and even-aged forests (Grundner and Schwappach 1922). In previous periods, the volume tables have been made by means of graphical or analytical method in the form of hardcopy tables, and now the tables are made exclusively analytically in the form of regression equations. According to Laar and Akca (2007), an early volume equation was introduced during the 1930s by Schumacher and associates. Especially since the 1960s, when computers became readily available to allow regression analyses to be carried out, forest scientists have developed many volume functions for various tree species in many parts of the world, and they continue to do so (West 2009). Zianis et al. (2005) gave a detailed overview of the equations that were developed to estimate the volume and biomass of trees in Europe. The determined number of obtained equations for biomass estimation was 607, and 230 for tree volume estimation. They stated that a relatively small number of equations had been developed for southern Europe, to which Bosnia and Herzegovina belongs. Until now, measuring the volume of trees directly using conventional tools has been impossible. However, with the advancements made in technologies such as terrestrial laser scanners (TLS) over the past decade, this has changed. TLS has evolved from experimental tools to established instruments in forest mensuration, offering the potential to measure tree volume directly (Calders et al. 2020; Demol et al. 2022; Abegg et al. 2023; An and Froese 2023). A relatively small number of volume tables have been developed for the territory of Bosnia and Herzegovina. In the previous period, two-entry volume tables for Norway spruce and silver fir have been made, as well as tariff tables and two-entry volume tables for estimating the volume of trees (European beech, sessile oak, common hornbeam and manna ash) in coppice forests. (Drinić et al. 1990). In recent times, tariff tables for estimating the volume of oak and beech in coppice forests in Bosnia and Herzegovina (Koprivica and Maunaga 2004, 2004a), and two-entry volume tables, for estimating the merchantable wood volume of spruce trees in the area of Canton 10 in the Federation of Bosnia and Herzegovina, have been created in the form of functions (Balić et al. 2020). In Bosnia and Herzegovina, tariff tables are used to estimate wood volumes during the preparation of forest management plans and implementation of annual felling plans (Drinić et al. 1990). Tariff tables that are applied in practice contain tabulated quantities for which parameters of mathematical models of equalization functions are not known because they are mostly obtained by graphical equalization. Furthermore, the measures of reliability of volume estimation are not known. According to Balić et al. (2020) there are indications that the application of the aforementioned tariff tables in forest management practice in Bosnia and Herzegovina results in certain differences in the amount of wood mass of merchantable wood in relation to the actual state of those volumes. According to the data of the second national forest inventory (2006-2009) in Bosnia and Herzegovina, the total area of forests and forest land is 3,231,000 ha, and the area of sessile oak forests (high and coppice forests) is 356,000 ha (Čabaravdić et al. 2016). In the Republic of Srpska, the area of sessile oak forests is 257,600 ha, or 70% of the total area of these forests in Bosnia and Herzegovina. Of that area, high forests cover only 76,900 ha or 30% (Dukić 2014). For the purpose of estimating the volume of oak trees in high forests, there are tariff tables (Drinić et al. 1990) used, which were created on the basis of two-entry volume tables for oak from the area of Germany authored by Schwappach from 1905 (Schwappach 1905; Grundner and Schwappach 1922), that is, tariff tables were made based on the constructed site index curves for the area of Bosnia and Herzegovina (Vukmirović 1963) and the aforementioned two-entry volume tables for the area of Germany. Tariff tables for other main types of trees (silver fir, Norway spruce, European beech, Scots pine and Austrian pine) were created in the same way. No data or written traces were found that show the applicability of the aforementioned two-entry volume tables in our conditions. The German tables do not differentiate between sessile oak and pedunculate oak, that is, they show the volume for both tree species. According to Špiranec (1975), given that the above tables were created by measurements on felled trees from pure, even-aged stands, it has been noticed long since that the above tables do not correspond to our stands (for the area of Croatia), and the need to create our tree-volume tables is evident. In particular, it is important to emphasize that in Bosnia and Herzegovina the sessile oak dominantly occurs in uneven-aged and mixed stands, in contrast to Croatia and Germany. The management of sessile oak forests in Bosnia and Herzegovina is atypical and is characterized by selection cuttings. The issue of volume tables that are in use is always a topical one, which must be given special attention, that is, work on checking existing and creating new tables must be a continuous activity. Based on that, according to the methodology introduced by Danilović et al. (2013), the collection of data for the production of volume and assortment tables for sessile oak was started. Volume tables are made by tree species, considering the fact that the ecological conditions and silviculture treatment of the stand affect the shape of the |