Aerobiological behaviour of Platanus L. pollen in Catalonia (North-East Spain)

The aim of this paper is to characterise the airborne behaviour of an allergenic and abundant pollen type, Platanus, in seven sites of the Aerobiological Network of Catalonia (Xarxa Aerobiològica de Catalunya, XAC). In Catalonia, the most extended Platanus species is Platanus × hybrida Brot., widely planted in forestry and as ornamental tree in streets and gardens. Naturalised specimens can also be found along river banks. The pollen records analysed are from different periods comprised between 1994 and 2000 in Barcelona, Bellaterra, Cambrils, Girona, Lleida, Manresa and Tarragona. All data were obtained using seven-day volumetric spore Hirst traps. Platanus pollination is concentrated in a few weeks, between March and April. Platanus pollen is present in all the atmospheric pollen spectra for the sites mentioned above. In Barcelona, Platanus pollen attained the highest concentrations, with an extreme annual index (sum of the mean daily concentrations) of 25790 in 1997, and a maximum daily concentration of 2567 P/m3 on 15th March 2000. The lowest annual index (647) corresponds to Cambrils, 2000, and the lowest maximum daily concentration (74 P/m3) was registered on 7th April 1996, in Manresa. The interannual variation of Platanus pollen values can be explained not only by meteorological parameters and the endogenous factors of the tree, but also by human activity such as elimination, pruning and watering.