Tuexenia 40: 33–52. Göttingen 2020. doi: 10.14471/2020.40.010, available online at www.zobodat.at Vegetation classification of acidophilous oak forests in Slovakia Vegetationsklassifikation bodensaurer Eichenwälder in der Slowakei Michal Slezák1, 2, * , Milan Valachovič3, , Drahoš Blanár4, František Máliš5, 6 , Dušan Senko3 & Hubert Žarnovičan7 1Institute of Forest Ecology, Slovak Academy of Sciences, Ľ. Štúra 2, 950 53 Zvolen, Slovakia; 2Podtatranské museum in Poprad, Vajanského 72/4, 058 01 Poprad, Slovakia; 3Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia; 4Administration of the Muránska planina National Park, J, Kráľa 12, 050 01 Revúca, Slovakia; 5Department of Phytology, Faculty of Forestry, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia; 6National Forest Centre, Forest Research Institute Zvolen, T. G. Masaryka 22, 960 01 Zvolen, Slovakia; 7Department of Landscape Ecology, Faculty of Natural Sciences, Comenius University, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia *Corresponding author, e-mail:
[email protected] Abstract Acidophilous oak forests are species-poor forest plant communities usually growing on mineral- poor geological and soil substrates. We compiled a large data set of 263 phytosociological relevés assigned to the Quercion roboris alliance in Slovakia to produce the first syntaxonomical revision at national level. Modified Twinspan algorithm was applied for numerical classification and