Although the year 2008 in Switzerland belongs to the ten to twelve warmest years since the beginning of measurements, the effects on the development of the vegetation were not very striking. An extreme excess of heat was never registered except in the winter months and in May. The mild winter simply had an effect on the flowering of the hazel, occurring early to very early. Besides this, most of the phenological spring phases were observed at the normal point of time. However, at some observation stations, a small number of phenological phases showed a completely unusual date of occurrence. These were observed very late or even extremely late (new records). Because of the fact that this phenomenon was not only observed at one single phenological phase, showing no spatial pattern and no height dependence, no explanation was found for this extraordinary behavior of these plants. This clearly reflects, despite intensive research on phenology during the last years, that many natural processes are until now not or not yet understood by man. According to the changing weather, the development of the vegetation showed neither a consistent nor an outstanding pattern in the summer. However, the early leaf-fall of the beech was quite striking, caused by the cold snap at the beginning of October.
The year 2008 can be considered as a normal phenological year, except the early flowering of the hazel, the inexplicable records (late observations) and the early leaf-fall of the beech.
A simple technique of random leaf collecting for biometric studies in a tree stand