Changes in the onset of Fagus sylvatica, L. phenological phases evaluated in different climate conditions

The changes of the meterological factors cause consequently the change of the onset of phenological phases, which are depend on them to a large extent. The extent to which they express themselves differs with the altitude. That is the reason why we set the aim to identify the level of differences in the chosen phenological phases onset during the whole vegetation period at the two various altitudes which represent different climatic conditions. We have chosen Fagus sylvatica, L. as the object of our survey. The phenological phases trends were evaluated during the 22-years long period range from 2986 to 2008. The results of the analyses show in general the higher variability of the autumnal phases onset at both altitudes. The change of the spring phases onset was found out only at higher located stand Stare Hory with more favourable moisture conditions. There can be seen gradual decreasing of the spring phenological onset gradient at the different altitudes. By the autumnal phenological phases, there was found out the opposite trend.