ZLV Online

Abstrakt

The paper provides an overview of various late spring frosts’ intensity during the flowering of pedunculate oak (Quercus robur L.). The research was carried out in 1987–2016 at selected phenological stations in Slovakia at altitudes up to 400 m. The frosts intensity was measured at meteorological stations at the height of 0.05 m and 2 m above the earth’s surface. Flowers frost damage was evaluated in three decades focused on temperature extremes. Above mentioned extremes occurred at stations up to 300 meters above sea level in 2001, 2007, 2011 and 2015. Trend analysis of flowering observations during 30 years recorded the shift to an earlier period. Most significantly, it was reflected at an altitude of 200 m. Temperature extremes occur irregularly. In other regions of Slovakia, frost damage to flowers may be more frequent, especially in locations microclimatically available for increased occurrence of frost, due to earlier onset of flowering.