ABSTRACT STUPÁR, Miloš: Distribution of size fractions of soil aggregates in stands of mountain area Poľana. [Bachelor thesis] – Technical University in Zvolen, Faculty of Forestry, Department of Natural Enviroment, Bachelor thesis supervisor: Ing. Marián Homolák, PhD. Degree of professional qualification: Bachelor, abbreviated „Bc.“ Zvolen TU, 2020, 35 p.The main topic of the presented bachelor thesis is the evaluation of soil structure based on the representation of size fractions of soil aggregates in stands with different representation two main agricultural trees, i.e. Norway spruce and European beech using research equipment designed for dry sievingof soil aggregates.From the obtained results of the analysis of the soil structure, significant differences were found from the mountain area of Poľana, in the representation of individual fractions of soil aggregates. In the stand with a predominant proportion of beech wood, there is higher percentage of soil aggregates with the largest dimensions. On the contrary, in spruce stand there was a higher occurrence of structurally unfavorable aggregates. The formation of a favorable soil structure and soil aggregates is to some extent influenced by the content of organic carbon, the analysis of which was also part of this work.Keywords: soil structure, soil aggregates, carbon in soil, dry sieving of soil sample