The Taxonomic Content of the Spectrum, Seasonality, and Concentrations of Airborne Pollen Grains in Vukovar-Syrmia County (Northeastern Croatia)

Airborne pollen monitoring in the city of Vukovar (Northeastern Croatia) was carried out using a Hirst-type spore trap, which was placed on the roof of a building at a height of 15 m above ground level. Over 5 consecutive years of airborne pollen monitoring, 76 pollen types from 45 plant families were identified. Of these, 29 pollen types belonged to arboreal species and 47 to non-arboreal species. Sixty-two percent of the total pollen was non-arboreal pollen. The main pollen types present in the airborne spectrum were Ambrosia artemisiifolia, Betula, Urtica, and Poaceae. Among the arboreal types, the genus Betula is the only taxon producing a high percentage in the pollen spectrum. Regarding allergenicity, A. artemisifolia, Betula, and Poaceae pose the highest allergy risk, while Urtica has a low risk of pollen allergy. Large differences in annual pollen sum and the seasonal dynamics of these dominant taxa during the study period were verified. The presence of the pollen in the air was influenced by weather conditions, showing in particular a positive correlation with the minimum air temperature for Betula and mean air temperature for Urtica, Poaceae, and A. artemisiifolia. However, the pollen concentration in the air was negatively correlated with precipitation for Betula, Urtica, and Poaceae and with humidity for A. artemisiifolia.