Aerobiological and phenological study of Pistacia in Cordoba city (Spain)

Pistacia species grow in temperate regions, and are widespread in the Mediterranean area. Two species can be found in the Iberian Peninsula: Pistacia lentiscus L and Pistacia terebinthus L. Airbbrne pollen from these species, recorded in some Spanish provinces, is regarded by some authors as potentially allergenic, and therefore should be of particular interest, given that these species are actually being introduced as ornamentals in parks and gardens. This paper deals with a study of daily and seasonal Pistacia airborne pollen counts in Cordoba city, analysed in parallel with field flowering phenology data. The study was carried out in Cordoba, using a volumetric Hirst-type sampler in accordance with Spanish Aerobiology Network guidelines. Phenological monitoring was performed weekly from January to May at 7 sites in the mountain areas north of Cordoba city. The Pistacia pollen season lasted an average of 41 days, from mid-March to end of April. Higher pollen counts were recorded in evening hours. The pollen index increased over the study period, and the pollen season coincided with phenological observations. Some airborne pollen grains were recorded once flowering had,finished, due to re-suspension or transport from other locations. Pistacia pollen counts in Cordoba were low, but sufficient to identify seasonal and daily patterns. This pollen type should be taken into account in pollen calendars, in order to fully inform potential allergy-sufferers. The number of trees introduced as ornamentals should be carefully controlled, since widespread planting could increase airborne pollen levels. (C) 2014 Elsevier B.V. All rights reserved.