EVALUATION OF PHENOLOGICAL STAGES OF EUROPEAN ROWAN (SORBUS AUCUPARIA L.)

This paper presents mainly graphic evaluate of spring vegetative phenological phases courses of European Rowan (Sorbus aucuparia L.) within period of 14 years of observations (19962009) around all Slovakia in altitudes from 100 to 1330 meters a.s.l. We evaluated this phenological phases: leave buds swelling, first leaves and general leaves production. Amount of available data for individual phenological phases is different. We went out from data from 55 phenological stations for leave buds swelling phenophase, from 49 stations for first leaves phenophase and only 21 stations for general leaves production phenophase. We concentrated on the influence of altitude and the influence of climate change on the run of phenological phase. Phenophases were observed according SHMU methodic. Mean beginning of leave buds swelling phenophase was 14th April. The earliest beginning was observed on 6th March 2002 in the altitude of 283 meters a.s.l. and the latest date of beginning was observed on 22th May 1997 in the altitude of 825 meters a.s.l. Range of leave buds swelling phenophase of European Rowan in Slovakia was 77 days. This phase has the biggest value of variation coefficient from all observed phenophases, and that is 4,6%. The earliest beginning of first leaves phenophase was observed on 24th March 2002 in the altitude of 255 meters a.s.l and the latest date of beginning of this phenophase was observed on 26th May in 1997 and 1998 in the altitude of 825 meters. Mean beginning was calculated on 25th April. Range of first leaves phenophase was 63 days. Value of variation coefficient was calculated on 3,7%. The earliest beginning of the last phenophase, general leaves production, was observed on 13th April in 1999 in the altitude of 272 meters a.s.l. and the latest date of beginning of this phenophase was observed on 14th June in 2004 in the altitude of 1330 meters a.s.l. and the mean begging of this phase was 6th May. Value of variation coefficient in Slovakia was calculated on 2,8% and range of this phenophase was 62 days. Within period of 14 years of observations, year of the earliest beginning of phenological phases was in 2007. It was caused probably because of above-normal spring temperatures. On the contrary, in 1996 some phenological phases began at the very latest.