Modeling olive pollen intensity in the Mediterranean region through analysis of emission sources

Aerobiological monitoring of Olea europaea L. is of great interest in the Mediterranean basin because olive pollen is one of the most represented pollen types of the airborne spectrumfor theMediterranean region, and olive pollen is considered one of the major cause of pollinosis in this region. The main aim of this study was to develop an airborne-pollenmap based on the Pollen Index across a 4-year period (2008–2011), to provide a continuous geographic map for pollen intensity that will have practical applications from the agronomical and allergological points of view. For this purpose, the main predictor variable was an index based on the distribution and abundance of potential sources of pollen emission, including intrinsic information about the general atmospheric patterns of pollen dispersal. In addition, meteorological variables were included in the modeling, together with spatial interpolation, to allowthe definition of a spatial model of the Pollen Index fromthe main olive cultivation areas in theMediterranean region. The results showmarked differences with respect to the dispersal patterns associated to the altitudinal gradient. The findings indicate that areas located at an altitude above 300 m a.s.l. receive greater amounts of olive pollen from shorter-distance pollen sources (maximum influence, 27 km) with respect to areas lower than 300 m a.s.l. (maximum influence, 59 km).