Seasonal changes in plant pollen concentrations over recent years in Vinnytsya, Central Ukraine

The control of plant pollen season patterns is especially important in the expectation of climate change, as the timing of potential varying pollen seasons affects the human population. An ever-increasing number of people suffer from hay fever symptoms with varying severity during the pollen season. This paper presents data on the seasonal variations of pollen concentration and the factors which are the likely causes of these variations in Vinnytsya, a city in Central Ukraine, in order to establish the apparent pattern of this variation and so improve the efficiency of hay fever control in Ukraine. Pollen counts were obtained by gravimetric and volumetric methods employing a Hirst-type volumetric spore trap. Alder (Alnus) and birch (Betula) peaks of pollen release occurred approximately 1 month earlier than was observed at the end of the twentieth century. This was due to the seasonal heat accumulation related to the appropriate temperature regimen registered in January and February prior to the growing season. Other trees – including poplar (Populus), maple (Acer), walnut (Juglans), common hazel (Corylus) – did not show distinct changes in pollen season pattern over the past decades. Mean daily temperature seems to be the leading factor promoting early season onset and a seasonal pollen peak shift of the grass and herb flora such as ragweed (Ambrosia). The shift of the ragweed seasonal pollen maximum towards later in the season correlated with higher temperatures during September. Our study has shown that droughts may also significantly decrease the ragweed pollen concentration