The Aerobiological Network of Extremadura

Abstract

The development of aerobiological networks in Spain has been made at the level of the autonomous communities. In Extremadura the sampling is conducted by the University of Extremadura. It began in 1993 with a station in Badajoz (BA). Two towns have had sampling on a temporary basis: Cáceres (CC 1996-2001) and Merida (ME 1996-1998). Currently there are 3 more sampling stations, which have been running since 2011: Plasencia (PL), Don Benito (DB) and Zafra (ZA), and CC again recently. The Annual Pollen Index (annual daily amounts) has shown an average of more than 50.000 pollen grains/m³ (23.532-92.655). In Badajoz (23 years) the results show a downward trend. The maximum daily concentration peaks were reached in 1997, with values of 6.102 grains/ m³ (CC 21/3) and 5.041 grains/m³ (BA 23/3). The five most important pollen types represent 78% of all the pollen registered. Their importance varies from one station to another. Quercus, Poaceae, Olea, Cupressaceae and Platanus, in this order, are the most abundant pollen types in all stations, except Platanus, which is the second most abundant in DB, and Olea, which is second in ZA. The data have been available on the research group’s website (www.aerouex.es) since 2006, and the record of visitors to the site shows a signi cant correlation with the concentration of pollen. Extremadura stands out for its high pollen concentrations of Poaceae and Quercus, due to its wide expanses of oak and cork trees. Pollen from ornamental sources –Cupressaceae and Platanus— shows a strong dependence on their abundance and distribution.