Phenological observations record the dynamics of vegetation in relation to meteorological conditions as well as the long-term trends in relation to climate change. We processed 20-year data of the flowering (BBCH scale 60), leaves unfolding (BBCH 11) and ripening of fruits (BBCH 86) of four woody species in south-west and central Slovakia. The phenological year begins with the flowering of the hazel. This phenophase has the largest amplitude of onset (52–65 days) as well as interannual variability (s_x = 20.2–33.4%) as it enters an unstable condition in early spring. At all stations, the order of phenophases is the same from the end of April. We found the highest vertical phenology gradient of the BBCH 60 Tilia cordata Mill. (6 days/100 m) and the smallest of BBCH 11 T. cordata (2.4 days/100). The statistically significant trends (p < 0.05) in shifting to the earlier period were in BBCH 60 Crataegus oxyacantha L. (0.4–0.5 days per year), BBCH 86 Corylus avellana L. (0.6 days per year), BBCH 60 Prunus spinosa L. (0.5–0,6 days per year) and BBCH 11 Prunus spinosa L. (0.6–0.7 days per year). These shifts indicate the change in the onset of the phenophases in south-west and central Slovakia.

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic