Types of hazel (Corylus spp.) and alder (Alnus spp.) pollen seasons in Sosnowiec 1997-2007 (Poland)

Abstract

This paper investigates pollen seasons for Corylus spp. and Alnus spp. for the years 1997-2007 in Sosnowiec, southern Poland. The research was conducted by means of the volumetric method using a Burkard-type spore trap. The duration of pollen seasons was determined by means of the 98% method. The aim of this study was to distinguish the types of the course of hazel and alder pollen seasons using cluster analysis, including non-hierarchical clustering of multi-feature objects - k-means clustering. The pollen seasons were divided into five types because of considerable variations from one year to another. For both taxons one dominant type was found, which was characterized by a very long period of compact pollen release with low values of the pollen count and by the occurrence of several maximums divided by periods of a lower pollen count. This work contains only a preliminary analysis on the types of pollen seasons because of relatively short data set. Future research on a larger series of measurements should be proved.