Fig. 4. Numerical classification (Ward's method with the Euclidean distance measure) of relevés presented by Hadač andSofron (1980). The presence/absence data of species in the herb layer was used. Relevé abbreviation consists of the original relevé number and an abbreviation of the association name (Sf-P Senecioni fuchsii-culti-Piceetum, Oa-P Oxalido acetosellae-Piceetum, Af-P Avenello flexuosae-Piceetum, Vm-P Vaccinio myrtilli-Piceetum, VmcP Vaccinio myrtilli-culti-Pinetum).