Influence of heat accumulation on olive tree flowering dates in a Mediterranean region

Airborne pollen data can represent an important source of information on flowering phenology at regional scale. The main aim of this research was to verify whether airborne pollen data of Olea europaea L. could be used as indicator of climate change in Mediterranean areas. In this work olive pollen data recorded in the last two decades (1984-2003) in North Sardinia (Italy) were presented. The trend of date of peak pollen concentration, was analysed. Finally, relation between trend of air temperature and trend of this parameter was investigated. The results suggested that the onset of flowering phase in Olea europaea L. was affected by rising spring temperature.