Analysis of changes in Betula pollen season start including the cycle of pollen concentration in atmospheric air.

Birch belongs to the most important allergenic taxa in Europe, therefore information on the start dates of the pollen season is very important for allergists and their patients as well as for climatologists. The study examined changes in the start of the birch pollen season as well as determined the trend of these changes. Pollen monitoring was performed in Lublin (eastern Poland) in the period 2001-2019 using the volumetric method. The Makra-test was used to detect periods with significantly higher or lower average of the onset than the average for the whole dataset. Two significant falls in the average of the pollen season start were found in 2007 and 2014. Besides, taking into account the 2-3-year rhythm of high and low concentrations of birch pollen in the atmospheric air, linear trends were fitted for the subsets of high and low abundance seasons. Significant changes in Betula pollen season start dates were only determined for the highly abundance seasons, while the results for seasons with a low concentration did not allow rejecting the hypothesis about the lack of a linear trend in the changes in the studied parameter. Moreover, a significant polynomial relationship was found between the beginning of a pollen season and the average values of monthly temperatures preceded a season. These analyses show that the start dates of the Betula pollen season are getting significantly earlier. The dynamics of changes differ between seasons with high and low concentrations of pollen.

Amaranthaceae pollen grains as indicator of climate change in Lublin (Poland).

Previous studies have demonstrated that plants are a very good indicator of global environmental variations. The responses of many plant species to climate change are confirmed by aerobiological research. This paper presents an analysis of many parameters of pollen seasons in the Amaranthaceae family based on measurements of pollen concentrations in atmospheric air. Pollen samples were collected with the volumetric method at a sampling site in Lublin (Poland) in 2001-2019. The obtained data were verified using statistical analyses. Moreover, the presence of pollenkitt on the pollen grain surface was examined in fresh anthers using scanning electron and light microscopes, since there are some difficulties in identification of Amaranthaceae pollen grains deposited on microscopic slides in aerobiological analysis. The pollen season in Amaranthaceae began on average on June 23 and ended on October 5, i.e. it lasted 105 days. The peak value and annual pollen sum were characterized by the highest variability in the study years in comparison with other season characteristics. The annual pollen sum was in the range from 183 to 725. Maximum concentrations were most often recorded in the second half of August, which is associated with the greatest risk of development of pollen allergy symptoms in sensitive subjects during this period. The results obtained in the 19-year study revealed that the pollen seasons began 14 days earlier. Similarly, the end of the season was accelerated by 24 days. The response of these plants to climate change also include the reduced pollen production by representatives of this family, which was manifested by a decrease in the annual sum of daily airborne pollen concentrations, on average by 35%, and a reduction in the maximum pollen concentration, on average by more than 60%. We found that temperature in May and June had an effect on pollen release, and relative air humidity in May influenced pollen concentrations. We noted significant similarities in the pollen release rate during the last 8 years of the study. The scanning electron microscopy examinations showed that the pollen grain surface in the representative of this family was covered completely or partially with pollenkitt. Hence, the apertures characteristic for pollen in this family were poorly visible. The presence of pollenkitt on the surface of these polyaperturate pollen grains may play an important role in preventing water loss during pollen migration in the air. Our research has demonstrated the response of plants flowering in summer to climate change. The results not only have practical importance for public health in the aspect of allergy risk but can also help to assess environmental changes.

Analysis of Fraxinus pollen seasons and forecast models based on meteorological factors.

INTRODUCTION AND OBJECTIVE: The timings of Fraxinus and Betula flowering and pollen release overlap, which may cause increased allergic reactions in sensitive people. The aim of the present study was to characterize Fraxinus pollen seasons in Lublin (central-eastern Poland) and to identify meteorological factors that most determine the occurrence of airborne pollen of this taxon, as well as obtain forecast models for the basic characteristics of the pollen season. MATERIAL AND METHODS: The study was conducted in Lublin during the period 2001-2016, employing the volumetric method. The seasons were compared by PCA (Principal Component Analysis). To determine relationships between meteorological conditions and the pattern of pollen seasons, regression analysis was used. Data for the period 2001-2015 were used to create forecast models by applying regression analysis, while the 2016 data served to verify these models. RESULTS: Season end date and seasonal peak date were characterized by the lowest variation. The biggest differences were found for peak value and total annual pollen sum. The average dates of occurrence of ash pollen grains in the air of Lublin were between 13 April 13 - 3 May 3, whereas, on average, the pollen peak date occurred on 23 April. The factor loading values for the PC1 variable indicate that it is most strongly correlated with peak value and total pollen sum, while the PC2 variable correlated with the pollen season start date and season duration (a negative correlation). Regression models were developed for the following pollen season characteristics: season start, end and duration, seasonal peak date, and total annual pollen sum. CONCLUSIONS: The fit of the forecast models was at the level of 62-94%. Analysis of the data showed that weather conditions mainly in February were important factors controlling the Fraxinus pollen season.

Warm and dry weather accelerates and elongates Cladosporium spore seasons in Poland.

Temperature is the environmental factor that systematically changes for decades and, as in plants and animals, can significantly affect the growth and development of fungi, including the abundance of their sporulation. During the time of study (2010-2012), a rapid increase in air temperature was observed in Poland, which coincided with the substantial decrease in rainfall. The increase in annual mean temperatures at three monitoring sites of this study was 0.9 °C in Lublin and Rzeszow (east Poland) and 2.0 °C in Poznan (west Poland). Such warming of air masses was comparable to the average global air temperature rise in the period of 1880-2012 accounting for 0.85 °C, as reported by the Intergovernmental Panel on Climate Change. Moreover, there was a substantial decrease in rainfall, ranging from 32.7 % (Poznan) to 43.0 % (Rzeszow). We have demonstrated that under such conditions the mean and median values of total Cladosporium spore counts significantly increased and the spore seasons were greatly accelerated. Moreover, earlier start and later end of the season caused its extension, lasting from over 20 days in Rzeszow to around 60 days in Lublin and Poznan, when the cumulative amount of 5-95 % of spores was considered. The time of reaching the cumulative amount of 50 % of spores was up to 25 days earlier (difference in Poznan between 2010 and 2012). There was also a striking acceleration of the date of the maximal Cladosporium spore concentration per cubic metre of air (26 days for Lublin, 43 for Poznan and 56 for Rzeszow).