The variation of the onset of Betula pendula (Roth.) flowering in Rzeszów, SE Poland: fluctuation or trend?

The global rise in air temperature has major implications for ecosystems, populations, ecology of many living organisms, public health as well as economy. Plants, like silver birch (Betula pendula Roth.), strongly respond to the climatic variation. Therefore, the species is a good indicator of the global climate change, especially warming. The phenological observation was undertaken to verify the hypothesis on an acceleration of the start of Betula pendula pollen release in the season. The investigations were carried out in 2000–2015 (16 years) in the Rzeszów area, SE Poland. On average, Betula pendula started to pollinate in the middle of April; the difference between the earliest and latest dates was nearly 1 month. The full pollination started on 18 April, on average. The timing of pollination strongly depended on the course of weather in February and March. The most crucial was temperature in the first half of March. Considering the synergistic impact of meteorological parameters, the most important were temperature and rainfall in January and February, rainfall in March and temperature just before the pollination. It was found that North Atlantic Circulation influenced pollen release in Betula pendula. The positive North Atlantic Oscillation in March and in December–March periods resulted in pollination onset. Tendency towards warmer average annual temperature was recorded, however the timing of phenophases did not follow it. Despite the strong relationship with temperature there was no acceleration of Betula pendula pollination. Probably, the climate warming effect on the onset and duration in Betula pendula phenophases would be detectable in longer than a 16-year period

Co-occurrence of airborne allergenic pollen grains and fungal spores in Rzeszów, Poland (2000-2002)

The co-occurrence of airborne allergenic pollen grains and fungal spores was estimated in Rzeszów in the years 2000-2002. The volumetric method was used in this aerobiological study. Six taxa of pollen grains and five types of fungal spores characterized by strong allergenicity and/or high concentrations in the air were analyzed. The time series of pollen grains and fungal spores were compared using PCA analysis. The periods of the greatest concentrations of tree pollen did not coincide with similar periods for herbaceous plants and fungal spores. From February to mid-March, Alnus pollen dominated in the air. The second period was characterized by Betula pollen. It occurred in April. Herbaceous pollen and fungal spores occurred in the air simultaneously (from mid May to the end of August), creating a risky situation for sensitized people. The periods of the highest concentrations of Epicoccum and Ganoderma fungal spores did not coincide with the same period for the examined plant taxa. In Rzeszów the probability of becoming exposed to very high concentrations of allergenic pollen and fungal spores at the same time was high, especially in July, when the highest concentrations of Poaceae, Alternaria and Cladosporium were noted. The hypersensitivity to only one plant or fungal allergen is rarely encountered. Under the present scenarios of global warming, pollen seasons of many taxa will be longer and sufferers will have year-long symptoms

Flowering and airborne pollen - a novel statistical approach

The time pattern of flowering significantly affects the pollen season, its beginning, length and the concentration of pollen grains in air. The forecasting models used in aerobiological studies were chiefly based on the elements of weather conditions; however, recently the phenology of pollen shedding has been taken into consideration in these models more and more frequently. The aim of the presented investigations was to determine to what extent the flowering and the occurrence of allergenic pollen grains in air coincided in time. The investigation was carried out in Rzeszów (SE Poland) in the years 2003-2004. The flowering of 19 allergenic plant species was observed and seven phenophases were distinguished. Aerobiological monitoring was based on the volumetric method. In the case of most herbaceous plants, the flowering period overlapped the pollen season, high concentrations of pollen being recorded throughout several phenophases. In general, the pollen of trees occurred during very short periods, frequently during one phenophase, while the investigated phenomena were missing each other. The most intensive growth of inflorescences of alder, hazel and birch was observed at the beginning of full fl owering or towards the end of full flowering

The impact of rainfall on the diurnal patterns of atmospheric pollen concentrations

Atmospheric precipitation removes the majority of biological and chemical pollutants from the lower parts of the troposphere. However, some studies infer increasing atmospheric pollen concentrations during precipitation events and/or thunderstorms, which are known to trigger allergic reactions (referred to as thunderstorm-triggered asthma). The aim of this study was to determine the impacts of precipitation on the diurnal variability of airborne pollen concentrations, with particular focus on the timing and intensity of precipitation events. We also considered the impacts of other meteorological elements on atmospheric pollen concentrations. The research was conducted in Rzeszów (SE Poland) from 2016 to 2018. We used two aerobiological and two meteorological stations in this study to determine potential spatial variability in the pollen response to rainfall, the diurnal precipitation changes, and the precipitation intensity in the city area. We determined the pollen response of four pollen types: Betula, Pinus, Poaceae, and Urtica, and we only included data from days that fulfilled restrictive criteria throughout all pollen seasons. We analysed a total of 81 days, which were divided into five groups according to precipitation intensity, the time of day of a precipitation event, and the type of pollen response to precipitation. Our results suggest that precipitation intensity was the dominant control on pollen concentrations; concentrations only decreased clearly under rainfall intensities of at least 5 $mm•h^{-1}$ and this value we recommended as threshold value for long lasting decrease of pollen concentrations in our region. Lower intensity rainfall events resulted in no change in atmospheric pollen concentrations throughout the day. We noted the occurrence of increased pollen concentration immediately before and during rainfall events. Further, other parameters were also found to influence pollen concentrations in the atmosphere, including relative humidity, the time of day, and biological factors such as the plant phenophase or the phase of a pollen season

Pseudothecial maturation and ascospore release of Leptosphaeria maculans and L. biglobosa in south-east Poland

Stem canker of brassicas is a severe disease of oilseed rape in Australia, Canada and Europe, including Poland. The disease is caused by Leptosphaeria maculans and L. biglobosa - two pathogens belonging to the class Dothideomycetes. The species differ in pathogenicity, but they have identical shape and size of fruiting bodies and spores of the generative and vegetative stages. Both pathogens are often found together in infected tissues of oilseed rape plants. The main goal of the experiments was to measure the rate of pseudothecial maturation and to monitor ascospore concentration of L. maculans and L. biglobosa in air samples. The paper is the first investigation on the generative stage development of these two species in south-east Poland. The studies were done for three consecutive years (2005-2007), for six most important months in pathogen development and plant infection, including 3 months in the spring (March - May) and 3 months in the autumn (September - November). The stage of pseudothecial maturation was assessed visually, based on the development of asci and ascospores. Monitoring of spore concentration in the air was performed using a Hirst-type 7-day volumetric trap. It was proved that differences in pseudothecial maturation rate in south-east Poland, encompassing the climatic regions of the Carpathian Foothills and Cracow, do not exceed two weeks within one season. The first and the highest ascospore concentration dates depended on weather conditions in a particular season. The total number of spores during the studied seasons varied from 9 to 12 spores/m3, which was from 70 to 90 times lower than the average from five other monitoring sites around Poland. The short exposition to spore showers and very small concentrations of L. maculans and L. biglobosa ascospores in air samples were the most probable reasons for relatively small damage of oilseed rape crops by stem canker in the south-east part of Poland

Forecasting model of Corylus, Alnus, and Betula pollen concentration levels using spatiotemporal correlation properties of pollen count

The aim of the study was to create and evaluate models for predicting high levels of daily pollen concentration of Corylus, Alnus, and Betula using a spatiotemporal correlation of pollen count. For each taxon, a high pollen count level was established according to the first allergy symptoms during exposure. The dataset was divided into a training set and a test set, using a stratified random split. For each taxon and city, the model was built using a random forest method. Corylus models performed poorly. However, the study revealed the possibility of predicting with substantial accuracy the occurrence of days with high pollen concentrations of Alnus and Betula using past pollen count data from monitoring sites. These results can be used for building (1) simpler models, which require data only from aerobiological monitoring sites, and (2) combined meteorological and aerobiological models for predicting high levels of pollen concentration

Grass pollen seasons in Poland against a background of the meteorological conditions

Artykuł dotyczy oceny sezonów pyłkowych Poaceae w Polsce w wybranych regionach. Celem pracy było przedstawienie wieloletniej zmienności początku, końca i długości sezonów pyłkowych traw oraz sezonowego indeksu pyłkowego (wartość SPI) w Polsce na tle warunków meteorologicznych. Badania były prowadzone w ośmiu miastach Polski, w okresie 1992-2014 (sezony 2003-2012 były wspólne dla wszystkich miast). Początek sezonu pyłkowego był względnie stały w okresie badawczym, sezony rozpoczynały się około 10 maja, nieco wcześniej w południowej części Polski. Koniec sezonu pyłkowego był bardziej zmienny w porównaniu do początku, jego termin wahał się od połowy lipca do połowy września. SPI wyraźnie zależał od temperatury i opadów w okresie kwiecień–sierpień. Dobowe stężenie maksymalne pyłku były odnotowywane pomiędzy końcem maja a pierwszą dekadą lipca, nie wykazano wyraźnej zależności pomiędzy dniem stężenia maksymalnego i warunkami pogodowymi, z wyjątkiem 2004 roku.The paper refers to the estimation of Poaceae pollen seasons in Poland in selected areas. The aim of the study was to present the long-term variability of the start, end and duration of grass pollen seasons and the seasonal pollen index (SPI) in Poland against a background of the meteorological conditions over pollen seasons. The study was performed in eight Polish cities in 1992-2014 (the common seasons were 2003-2012). Pollen season start was relatively stable in the studied period, the seasons began about the 10th of May, a bit earlier in the south part of Poland. Pollen season ends were more changeable in comparison to the season start and fluctuated from the middle of July to the middle of September. SPI clearly depended on temperature and precipitation in April-August. Daily maximum pollen concentrations were achieved between the end of May and the first decade of July and no evident relationship between this day and weather conditions was found, apart from 2004

Grass pollen seasons in Poland against a background of the meteorological conditions

The paper refers to the estimation of Poaceae pollen seasons in Poland in selected areas. The aim of the study was to present the long-term variability of the start, end and duration of grass pollen seasons and the seasonal pollen index (SPI) in Poland against a background of the meteorological conditions over pollen seasons. The study was performed in eight Polish cities in 1992-2014 (the common seasons were 2003-2012). Pollen season start was relatively stable in the studied period, the seasons began about the 10th of May, a bit earlier in the south part of Poland. Pollen season ends were more changeable in comparison to the season start and fluctuated from the middle of July to the middle of September. SPI clearly depended on temperature and precipitation in April-August. Daily maximum pollen concentrations were achieved between the end of May and the first decade of July and no evident relationship between this day and weather conditions was found, apart from 2004

Co-occurrence of Artemisia and Ambrosia pollen seasons against the background of the synoptic situations in Poland

The Asteraceae family is one of the largest families, comprising 67 genera and 264 species in Poland. However, only a few genera, including Artemisia and Ambrosia are potential allergenic sources. The aim of the study was to estimate how often and to what degree Artemisia and Ambrosia pollen seasons co-occur intensifying human health risk, and how synoptic situations influence frequency of days with high pollen concentrations of both taxa. Artemisia and Ambrosia pollen data were collected, using the volumetric method, at 8 sites in Poland. Daily concentrations of Artemisia pollen equal to 30 grains or more and Ambrosia pollen equal to 10 grains or more were accepted as high values. Concentrations of more than 10 pollen grains were defined as high in the case of Ambrosia because its allergenicity is considered higher. High concentrations were confronted with synoptic situations. Analysis was performed on the basis of two calendars on circulation types of atmosphere in Poland (Niedźwiedź, 2006, 2015). Co-occurrence of Artemisia and Ambrosia pollen seasons is being found most often, when Ambrosia pollen season starts in the first half of August. If it happens in the last 10 days of August high pollen concentrations of Artemisia and Ambrosia do not occur at the same days. At three sites (Sosnowiec, Rzeszów, Lublin) high Ambrosia pollen concentrations during the Artemisia pollen season appear more often than in other sites under question. The high Artemisia pollen concentrations occur, when continental or polar maritime old air masses inflow into Poland. The impact of air masses on high Ambrosia pollen concentrations depends on site localizations. It is likely, that in the south-eastern part of Poland high Ambrosia pollen concentrations result from the pollen transport from east-south-south-westerly directions and the local sources. Co-occurrence of both taxa pollen seasons depends on the air masses inflow and appears more often in a southeastern part of Poland

The grass pollen in the air of selected Polish cities in 2007

Praca przedstawia przebieg sezonu pylenia traw w roku 2007 w Białymstoku, Bydgoszczy, Krakowie, Lublinie, Łodzi, Rzeszowie, Sosnowcu, Szczecinie, Warszawie i we Wrocławiu. Badania prowadzono metodą objętościową przy zastosowaniu aparatów typu Burkard i Lanzoni. Sezon pyłkowy wyznaczono metodą 98%. Najwcześniej pyłek traw zarejestrowano we Wrocławiu i w Krakowie (20, 30 kwietnia), najpóźniej w Białymstoku (13 maja). Największą maksymalną koncentrację pyłku zanotowano w Łodzi (513 ziaren/m3), najniższą w Krakowie (106 ziaren/m3). Okres maksymalnych stężeń pyłku traw rejestrowano między 29 maja i 21 czerwca.This paper presents the curse of grass pollination seasons in the cities Białystok, Bydgoszcz, Kraków, Lublin, Łódź, Rzeszów, Sosnowiec, Szczecin, Warszawa and Wrocław in 2007. Measurements were performed by the volumetric method with the use of a Burkard and Lanzoni Spore Trap. The duration of the pollen seasons was defined as the period in which 98 % of the annual total catch occurred. The pollen seasons of grass started first in Wrocław and Kraków (20, 30 April), the latest in Białystok (13 May). The highest concentration of pollen grains was noted in Łódź (513 z/m3), the lowest in Kraków (106 z/m3). The period of the maximum concentrations was recorded in 29 May and the off 21 June