Division of Biology, Faculty of Science, University of Zagreb
Abstract
The flowering season and the pollen season of Corylus and Castanea were analyzed and compared in Trieste over a period of 14 years (1991–2004). Agreat variability in the flowering phenophase progression was found both among plants and from year to year. The pollen seasons of Corylus and Castanea were longer than the respective flowering seasons. A lack of correlation between the maximum flowering and the maximum pollen concentration was observed, the highest airborne pollen counts occurring two or more weeks after the maximum flowering. Given the geographical complexity of the area around Trieste, the onset of the flowering of Corylus and Castanea does not occur at the same time everywhere, and grains coming from different local and extra-local sources, characterized by a late blooming, were also found. Medium-long range transport from Slovenia should also be considered
