Phenological annual review for 2008

Although the year 2008 in Switzerland belongs to the 10th to 12th 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 of the winter months and May. The mild winter simply had an effect on the flowering of the hazel, occurring early to very early. The flowering of coltsfoot showed large differences of the occurrence date. Besides this, most of the phenological spring phases were observed at the normal point in time. However, at some observation stations, a small number of phenological phases showed a completely unusual date of occurrence. These observations were very late or even extremely late (new records) and no explanation was found for this extraordinary behavior of these plants. This reflects clearly, despite intensive research on phenology during the last years, that many natural processes are until now not or not yet understood by the human being. According to the alternating 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 irregular pattern of the flowering of coltsfoot, the inexplicable records (late observations) and the early leaf-fall of the beech.