Boxplots showing the variability of altitude and other environmental indicators (i.e. Landolt's moisture, light, temperature, continentality, soil reaction, nutrients, humus) for each plant community. The abbreviations used are referred to the following plant association: Phy-Fes for Phyteumo-Festucetum, Car-Nar for Carici-Nardetum, Cen-Arr for Centaureo-Arrhenatheretum, Hol-Chr for Holco-Chrysopogonetum, Poo-Fes for Poo-Festucetum and Phy-Mes for Phyteumo-Mesobrometum.