High Pollen Concentrations Research Articles

Pollen distribution and transportation patterns in surface sediments of Liaodong Bay, China

Understanding pollen transport pathways and dispersal mechanism from the land to sea is a prerequisite for marine palynological study. Palynological analysis of 164 surface sediment samples in Liaodong Bay, and 39 analogous surface alluvium samples from its five inflowing rivers, identifies the distribution patterns, pathways and possible sources of pollen and spores. The results show that pollen and spore assemblages in surface sediments are well correlated to regional vegetation distribution, and the variations of pollen assemblage in different parts of Liaodong Bay reflected local vegetation changes along the coast. High pollen concentrations are mainly distributed in the estuaries of inflowing rivers, coastal waters and sea muddy areas. The pollen assemblage characteristics of alluvial samples are similar to those from coastal waters with water depths <8.5 m. Samples from the alluvium and surface sediments of coastal waters were dominated by herbaceous pollen taxa including Artemisia, Amaranthaceae, Poaceae, Cyperaceae and Typha. Herbaceous pollen percentages and concentrations decreased as the water depth increased, indicating that pollen and spores in the coastal waters of Liaodong Bay are mainly carried by the inflowing rivers. However, pollen assemblages for samples with water depth >8.5 m are significantly different from those of the alluvium. In samples taken below a depth of 8.5 m, the arboreal pollen is dominated by airborne Pinus, and there is a high number of the waterborne Selaginella fern spores, both of which are sourced from a wider region. In the Liaodong Bay, both wind and ocean current transportation determines the pollen distribution patterns in deeper waters, while fluvial and longshore current transportation determines the pollen assemblages found in shallow waters. The dispersal characteristics of pollen assemblages between the land and the sea in Liaodong Bay provide a theoretical basis for the interpretation of fossil pollen assemblages and past sea level changes.

Pollen Monitoring in the City of Ivano-Frankivsk, Western Ukraine

The results of aeropalynological studies in Ivano-Frankivsk during 2013–2015 are presented in this article. The studies were conducted using a specially designed gravimetric Durham pollen trap installed at a height of 24 m from the ground. We determined that pollen grains of the following taxa dominate in the city’s aeropalynological spectrum: &lt;em&gt;Corylus&lt;/em&gt;, &lt;em&gt;Alnus&lt;/em&gt;, &lt;em&gt;Betula&lt;/em&gt;, &lt;em&gt;Populus&lt;/em&gt;, &lt;em&gt;Fraxinus&lt;/em&gt;, &lt;em&gt;Salix&lt;/em&gt;, &lt;em&gt;Carpinus&lt;/em&gt;, &lt;em&gt;Quercus&lt;/em&gt;, &lt;em&gt;Pinus&lt;/em&gt;, &lt;em&gt;Picea&lt;/em&gt;, Poaceae, Urticaceae, &lt;em&gt;Artemisia&lt;/em&gt;, and &lt;em&gt;Ambrosia&lt;/em&gt;. Pollen grains from woody plants dominate the aeropalynological spectrum. The considerable presence of the tree pollen grains in the ambient air is due to the geographical location of Ivano-Frankivsk in the forest-steppe zone of Ukraine. Pollen season of allergenic plants lasts from the second week of February to early October. The most unfavorable period for patients with pollen allergy in Ivano-Frankivsk is April, when there is a simultaneous appearance of high concentrations airborne allergenic pollen of &lt;em&gt;Betula&lt;/em&gt;, &lt;em&gt;Fraxinus&lt;/em&gt;, and &lt;em&gt;Carpinus&lt;/em&gt;. From the second week of May to mid-July, high (&amp;gt;50 pollen grains/m&lt;sup&gt;3&lt;/sup&gt;) concentrations of allergenic pollen of the Poaceae family members are detected in the air. In the second half of August and early September, high concentrations of allergenic &lt;em&gt;Ambrosia &lt;/em&gt;pollen were recorded in the city air. Conducting of pollen monitoring in the city is extremely necessary for prevention, diagnosis, and treatment of pollen allergy.

Spatiotemporal assessment of airborne pollen in the urban environment: The pollenscape of Thessaloniki as a case study

Pollen is indispensable for life. But, as it may trigger allergic reactions, it can become a biological pollutant, thus requiring monitoring. In urban ecosystems, this is usually done with sampling at rooftop level; exposure to allergenic pollen at ground level is largely unknown. Using the Hirst-type methodology, we explore here how the qualitative, quantitative and phenological features of airborne pollen change horizontally, in different sites of the urban environment, and vertically, when pollen sources are primarily local. We sampled for two years in Thessaloniki, Greece, at six near-ground stations (at 1.5 m) and one at rooftop-level (30 m high). There was a large variability in quantitative pollen features among stations, but Urticaceae, Cupressaceae, Platanus, Pinaceae, and Quercus were the five most abundantly represented taxa in the air, both near the ground and at rooftop level, exceeding there an annual pollen integral of 1000 grains m−3. We found height to have a clear effect on pollen concentration: near the ground, it was three times higher for the entire pollen spectrum and up to 11 times higher for individual taxa. Assuming an exponential decay of pollen with distance from the ground, we calculated pollen concentration for the entire spectrum to decline to half the near-ground value every 19 m and at higher rates for individual taxa. Pollen season also varied largely among stations; a semi-natural station, next to a peri-urban forest, differed from the purely urban stations in having higher pollen concentration and shorter pollen season. For only two taxa, Urticaceae and Cupressaceae, pollen concentrations exceeded thresholds associated with high risk for more than 5% of the year. We conclude that pollen is far from homogeneously distributed within the urban environment, and that height has a strong effect on the low-altitude vertical profile of pollen. At an applied level, this study provides necessary information for more efficient monitoring of airborne pollen and for designing and managing urban green spaces, particularly under the current climate change and the associated higher demand for urban green.

Temporal Changes in Pollen Grain Concentration Predict Short-Term Clinical Outcomes in Acute Coronary Syndromes

Atmospheric changes in pollen concentration may affect human health by triggering allergic processes such as exacerbation of asthma. We sought to assess if high pollen concentrations were associated with different acute coronary syndrome (ACS) subtype presentation and short-term clinical outcomes.

Oak pollen concentration in the air of selected Polish cities in 2020

The study aims to compare the oak pollen season in selected Polish cities: Bialystok, Bydgoszcz, Cracow, Katowice, Piotrkow Trybunalski, Lublin, Olsztyn, Opole, Szczecin, Warsaw, and Wroclaw in 2020. Measurements were made using the volumetric method, with a Hirst-type sampler. Oak pollen season, defined as the period with 98% of the annual total catch, started between April 14th (in Opole) and April 25th (in Lublin). The season ended on June 1st at the latest; in Sosnowiec, Bydgoszcz, Olsztyn, and Bialystok. It lasted from 30 to 47 days (37 days on average). The maximum daily oak pollen concentrations were observed between April 24th and May 11th. The highest annual sum of oak pollen grains (SPI) was recorded in Lublin, while the lowest in Bialystok. The highest concentrations of 596 oak pollen grains/m3 were noted in Lublin on April 28th. The longest exposure to high concentrations of oak pollen (&gt; 91 grains/m3), lasting 12–13 days, was recorded in Lublin, Opole, and Wroclaw.

A Pilot Forecasting System for Epidemic Thunderstorm Asthma in Southeastern Australia

AbstractIn November 2016, an unprecedented epidemic thunderstorm asthma event in Victoria, Australia, resulted in many thousands of people developing breathing difficulties in a very short period of time, including 10 deaths, and created extreme demand across the Victorian health services. To better prepare for future events, a pilot forecasting system for epidemic thunderstorm asthma (ETSA) risk has been developed for Victoria. The system uses a categorical risk-based approach, combining operational forecasting of gusty winds in severe thunderstorms with statistical forecasts of high ambient grass pollen concentrations, which together generate the risk of epidemic thunderstorm asthma. This pilot system provides the first routine daily epidemic thunderstorm asthma risk forecasting service in the world that covers a wide area, and integrates into the health, ambulance, and emergency management sector. Epidemic thunderstorm asthma events have historically occurred infrequently, and no event of similar magnitude has impacted the Victorian health system since. However, during the first three years of the pilot, 2017–19, two high asthma presentation events and four moderate asthma presentation events were identified from public hospital emergency department records. The ETSA risk forecasts showed skill in discriminating between days with and without health impacts. However, even with hindsight of the actual weather and airborne grass pollen conditions, some high asthma presentation events occurred in districts that were assessed as low risk for ETSA, reflecting the challenge of predicting this unusual phenomenon.

The association between airborne pollen monitoring and sensitization in the hot desert climate

BackgroundPollen is a major cause of allergic respiratory diseases. In Qatar, data on the presence and prevalence of allergenic airborne types of pollen is quite limited.MethodsThe study aimed to determine and correlate the most frequently implicated airborne pollen detected by aerobiological monitoring samplers in respiratory allergy symptoms. An aerobiological survey was started on May 8, 2017. Airborne pollen was collected using two Hirst type seven-day recorder volumetric traps. Skin prick test in patients attending allergy clinics in Doha using commercial extracts was conducted.ResultsTwenty-five pollen types representing the native, as well as the introduced plants, with a relatively low daily mean concentration were observed from May 2017 to May 2019. The highest pollen concentrations were reached by Amaranthaceae (58.9%), followed by Poaceae (21.7%). SPT revealed a comparatively higher degree of sensitization to pollen. Among 940 patients, 204 were sensitized to pollen (54% female) with 135 (66.2%) and 114 (55.8%) to Amaranthaceae and Poaceae, respectively. Some patients had polysensitization. There was a statistically significant association between Amaranthaceae, and asthma (r = 0.169, P = 0.016) and allergic rhinitis (r = 0.177, P = 0.012).ConclusionsThis is the first study to monitor airborne pollen in the state of Qatar. The main pollen detected were Amaranthaceae and Poaceae. Pollen may represent a possible exacerbating factor in adult patients with allergic diseases such as asthma and allergic rhinitis.

Pollen dispersal patterns in marine surface sediments from the San Jorge Gulf, SE Patagonia (Argentina)

This paper analyzes the distribution patterns of pollen and spore assemblages in modern surface sediments recovered from the bottom of the San Jorge Gulf (SJG) and from offshore sites, in relation to the location of different phytogeographic provinces surrounding the SJG, including the distant forest from southwestern Patagonia. Results reveal that pollen spectra are dominated by Chenopodiaceae-Amaranthaceae, Poaceae, Asteraceae subf. Asteroideae, Colliguaja integerrima and Ephedra sp.; which represents the vegetation adjacent to the SJG. Overall, the pollen distribution in surface sediments reflects the location of the different phytogeographic provinces and will be used as modern-analogues to document vegetation history around the SJG. Pollen assemblages also reveal the latitudinal variation of vegetation taxa in the Patagonian steppe, which is characterized by a slight increase in herbaceous pollen and a decrease in high shrubs (e.g. Colliguaja integerrima) towards the southern-central part of the SJG. Furthermore, we identified two pollen taxa from the southwestern Patagonian forest, Nothofagus and Podocarpus that could be used as indicators of past dynamics and variations of the Southern Westerly Wind Belt (SWWB) in the SJG during the Late Pleistocene and Holocene. High pollen concentrations are recorded at the central part of the SJG (480–8080 grains/g), while low concentrations are measured in the northern and southern parts of the Gulf, as well as at offshore sites (26–1806 grains/g). The pollen distribution in the study area is most likely governed by the SWWB in combination with the marine sediment composition and surface currents flowing through the SJG.

Palynomorphs in surface sediments of the North-Western Black Sea as indicators of environmental conditions

Most previous Black Sea palynology studies have used pollen-spore assemblages as proxies for climate and landscape changes, and dinocyst assemblages as proxies for surface water salinity. However, there are few data on within-region variations in these assemblages using large sets of surface samples and a full suite of palynomorphs, including terrigenous pollen + spores, freshwater algal spores, and organic remains of marine microplankton, micro- and meiobenthos. Here we fill this knowledge gap, using results from a palynological study of 43 surface samples from water depths of 71–905 mbsl on the Ukrainian Shelf and adjoining continental slope, NW Black Sea. The palynology samples were collected in conjunction with water and sediment chemistry data, grain-size, micropaleontological and meiobenthos data from the EU-FP6 project HERMES “Hotspot Ecosystems Research on the Margins of European Seas”. This dataset uniquely covers shelf and upper slope areas east and west of the Odessa-Sinop Fault Zone (OSFZ) that delimits areas of lower and higher hydrocarbon gas contents, respectively.The new data show that on the wide shelf with a shallow (ca. 80 m) oxycline, pollen assemblages differ from classical models for marine pollen transport. On the Ukrainian Shelf, pollen concentrations are extraordinarily high far offshore and the grains are often pyrite-infilled. These features apparently reflect high pollen preservation potential in low oxygen sediments, probably enhanced by cross-shelf transport of land-derived particulate organic matter. The new data have important consequences for accurate modelling of carbon burial and storage in epicontinental seas, and they provide a baseline for evaluating marine pollen concentrations expected to reflect the early Neolithic farming on the Ukrainian shelf. Furthermore, although large concentrations of dinocysts comprise more than half of the total Non-Pollen Palynomorphs (NPP), the high pollen concentrations skew the P:D index (pollen:dinocyst ratio) commonly used to evaluate changes in paleo-shoreline (proxy sea-level) positions. Despite the discharge of several large rivers to the Ukrainian Shelf, there are negligible traces of freshwater algae in the HERMES samples except at Sta. 15 where Pediastrum is abundant. Overall, palynomorphs of terrestrial origin make up about half (52%) of the acid-resistant organic-walled particles on the outer NW Black Sea Shelf and adjacent slope.The abundances of the major micro- and meiobenthic palynomorph groups show the same trends east and west of the OSFZ as the micropaleontological data reported for the HERMES samples taken at the same sites. The combined microzooplankton and zoobenthos surface assemblage data provide an important new baseline for evaluating historical and past changes in biodiversity and aquatic foodweb structure in the now polluted NW Black Sea. Comparison can also be made with foodweb reconstructions for Permian black shales.

High Ambrosia pollen concentrations in Poland respecting the long distance transport (LDT)

High Ambrosia pollen concentrations in Poland rather rarely come from the local sources. The aim of this study was to define the temporal and spatial differences of the high Ambrosia pollen concentrations by creating models for the pollen transport from the distant sources. This study was thought to determine the direction of the air masses inflow into Poland, carrying Ambrosia pollen, from areas of the bordering countries with the pollen concentrations higher than iSTOTEN_n Poland. Pollen and meteorological datasets at 8 monitoring sites in Poland, and daily pollen concentrations at 11 sites in the Czech Republic, 5 sites in Slovakia and 3 sites in Ukraine were analysed recently. Days with concentrations ≥10 Pollen/m3 and concurrent meteorological situations were analysed in great deal. The HYSPLIT model was applied to compute backward trajectories up to 4 days backward (96 h) and at three altitudes: 20, 500 and 1000 m above ground level (a.g.l.). High pollen concentrations occur most frequently when the air masses inflow into Poland from southerly (S, SE, SW, 44%) and easterly (E, 6%) directions and in no advection situations (25%). In years with the highest frequency of days over 10 Pollen/m3, the prevailing directions of the pollen influx into Poland were from the South (2004–2006, 2008, 2011) but in one year (2014) from the East. Trajectories for the studied period show that air masses come most frequently from Slovakia and the Czech Republic. Sometimes, the Ambrosia pollen transport happens from Ukraine.

The influence of atmospheric circulation conditions on Betula and Alnus pollen concentrations in Wroc\u0142aw, Poland

The influence of atmospheric circulation conditions on pollen concentrations of two taxons (Betula and Alnus) in Wroclaw, Poland, for the years 2005–2014 was analysed. Pollen concentration was analysed separately for twenty circulation types that were determined using objective classification. The results indicate the atmospheric circulation conditions favourable for both low and high pollen concentrations over Central Europe. Pollen concentrations vary significantly according to circulation types. The highest pollen concentrations for both taxons are typical for warm, sunny, and dry anticyclonic circulation types with anticyclone in the lower and upper troposphere, especially for types with advection from the SW. The lowest pollen concentrations are observed for cold, wet, and cloudy cyclonic types with advection from the northern sectors. There is also a positive and statistically significant trend in the frequency of circulation types favourable for high concentrations of Betula and Alnus.

Occurrence of pollen season at the end of the first trimester predicts clinical atopic diseases in the offspring: A Finnish population-based study.

To evaluate the association between potential exposure to different pollen concentrations at the 11th fetal week and subsequent clinical atopic diseases. Parents of 1- to 4-year-old children (N=3035) returned a questionnaire regarding physician-diagnosed atopic diseases. The children were born between 2001 and 2005 in the province of South Karelia, Finland. Results of allergy tests were collected from patient records in the area. The prevalence of atopic diseases with sensitisation was higher in children whose 11th fetal week occurred during pollen rather than non-pollen season: atopic eczema 6.3% vs. 4.3% (adjusted odds ratio, aOR 1.58, 95% CI 1.10─2.28), food allergy 5.7% vs. 3.9% (1.63; 1.12─2.38), respiratory allergy or asthma 3.7% vs. 2.2% (2.03; 1.24─3.33) and any atopic diseases 7.4% vs. 5.5% (1.48; 1.07─2.05), respectively. Respectively, the prevalence was higher in the children exposed to high rather than low tree pollen concentrations (>1000 vs. <10 particles/m3) at the 11th fetal week: 12.1% vs. 4.4% (3.35; 1.89─5.95), 12.1% vs. 3.9% (3.77; 2.11─6.72), 4.7% vs. 2.5% (2.95; 1.21─7.20) and 14.0% vs. 5.7% (3.15; 1.86─5.35). Coincidence of potential exposure to high tree pollen concentrations at the 11th fetal week is associated with subsequent clinical atopic diseases with sensitisation.

The Association Between Airborne Pollen Monitoring and Sensitization in the Hot Desert Climate

Background: Pollen is a major cause of allergic respiratory diseases. In Qatar, data on the presence and prevalence of allergenic airborne types of pollen is quite limited. Methods: The study aimed to determine and correlate the most frequently implicated airborne pollen detected by aerobiological monitoring samplers in respiratory allergy symptoms. An aerobiological survey was started on May 8, 2017. Airborne pollen was collected using two Hirst type seven-day recorder volumetric traps. Skin prick test in patients attending allergy clinics in Doha using commercial extracts was conducted. Results: Twenty-fve pollen types representing the native, as well as the introduced plants, with a relatively low daily mean concentration were observed from May 2017 to May 2019. The highest pollen concentrations were reached by Amaranthaceae (58.9%), followed by Poaceae (21.7%). SPT revealed a comparatively higher degree of sensitization to pollen. Among 940 patients, 204 were sensitized to pollen (54% female) with 135 (66.2%) and 114 (55.8%) to Amaranthaceae and Poaceae, respectively. Some patients had polysensitization. There was a statistically signifcant association between Amaranthaceae, and asthma (r=0.169, P=0.016) and allergic rhinitis (r=0.177, P=0.012). Conclusions: This is the frst study to monitor airborne pollen in the state of Qatar. The main pollen detected were Amaranthaceae and Poaceae. Pollen may represent a possible exacerbating factor in adult patients with allergic diseases such as asthma and allergic rhinitis.

Is the birch pollen threat the same indoors and outdoors?

The study compares the concentration of birch pollen indoors and outdoors in 2019. The investigations were carried out using the volumetricmethod (Hirst type pollen sampler). Seasonal Pollen Index (SPI) was estimated as the sum of daily average pollen concentrations in the givenseason. Pollen season was defined as the period in which 98% of the annual total catch occurred. The birch pollen season in 2019 started at thebeginning of April. The first pollen grains were recorded in internal samples on the April 4th, only one day after than in external air. In generally theperiod of occurrence of birch pollen in the outdoor and indoor air coincided (28/29 days). The maximum values of seasonal birch pollen countwere noted on April 18th (467 g/m3) and on April 20th (1971 g/m3) (indoor/outdoor). The annual pollen sum of birch noted outdoor reached 18 148, inside seminary room – 3141, which is 17% of total. Three peaks of high concentrations of birch pollen were noted outside, which was only partly reflected in the indoor air. This may be result of closing the windows for the night and on weekends. The threat of birch pollen allergens during the 2019 pollen season was high. For most of the season in outside air were noted values in which patients report severe allergy symptoms. Such concentrations were recorded for 9 days indoor with concentration above 90 grains/m3 (acute symptoms of allergy).

Large-scale pollen distribution in marine surface sediments from the Bohai Sea, China: Insights into pollen provenance, transport, deposition, and coastal-shelf paleoenvironment

To elucidate the mechanisms responsible for pollen and spore transportation and deposition in the Bohai Sea, fully covered seafloor-surface sediment samples were collected for palynological and grain size analysis. The results reveal that the pollen and spore concentrations were higher in the head of Liaodong Bay and in the muddy area of the Bohai Sea. The Yellow River was the main source of pollen and spores in the Bohai Sea. The sediments with relatively high pollen concentrations consisted mainly of clay and fine silt, whereas sediment with lower pollen concentrations was mostly fine sand. In addition, the percentages of Pinus pollen and pteridophyte spores increased with increasing sea water depth, while other arboreal (excluding Pinus) and herbaceous pollen generally decreased with increasing distance from the shore. The relationship between the pollen taxa and the water depth of the sampling points shows that the fluvial water plays a predominant role in pollen transmission within 20 m of water depth, while the wind is the main driving force for pollen transmission when the water depth exceeds 20 m. Although Pinus pollen and pteridophyte spores were over-represented, there was good correlation between marine pollen signals and terrestrial vegetation. Apart from the influence of rivers and wind on pollen and spore deposition, the tidal currents and circulation were also main force responsible for transporting sediment and determining the differentiation of pollen and spores in the Bohai Sea. The comparison of pollen and spore percentages between surface sediment and fossil records from sedimentary cores made it possible to identify changes in pollen sources and transport mechanisms. Meanwhile, the percentage fluctuations of fossil Pinus and herbaceous pollen revealed concomitant changes of the sea level and climate. These findings are of paramount importance to the interpretation of Quaternary marine pollen data from the Bohai Sea, China.

Prediction of airborne pollen concentrations for the plane tree as a tool for evaluating allergy risk in urban green areas

The different species of the genus Platanus, commonly known as plane trees, are widely grown as an ornamental species in Mediterranean cities over recent years. The pollen of these species is a major source of allergens. However, surprisingly little published research has addressed methods for predicting the allergy risk prompted by this pollen. In this work, we developed models for predicting airborne Platanus pollen concentrations constructed using data from central Spain. Predictions are very useful to alert citizens and give allergy patients advanced warning of expected high airborne pollen concentrations. The prediction models indicate that airborne Platanus pollen concentrations can be forecasted up to seven days (one week) in advance, using a method which combines the analysis of long-term aerobiological data (in this case, over the eleven-year study period), in order to detect seasonal trends within time-series, with the modelling of short-term fluctuations in airborne pollen concentrations prompted by daily changes in meteorological variables and pollen concentrations over the previous days. The meteorological variables studied were maximum and minimum temperature, rainfall and relative humidity. The results of the validation of prediction models yielded a coefficient of correlation between observed and predicted values of R = 0.7, indicating that these models predict most of the pollen peaks in the airborne pollen curve.

Prevalence of allergic rhinitis and asthma in Poland in relation to pollen counts.

IntroductionDespite the known role of pollen allergens in causing allergy symptoms in sensitized individuals, there are few publications investigating the relationship between pollen exposure in different regions and the prevalence of inhalant allergy.AimTo assess the association between the prevalence of allergic rhinitis and asthma and the degree of exposure to pollen in various regions of Poland.Material and methodsCompleted questionnaires of 9,443 subjects living in four urban centres (Wroclaw, Katowice, Warsaw, Bialystok), collected within part of the ECAP project, were analyzed. Children aged 6–7 (n = 2,278), adolescents aged 13–14 (n = 2,418), and adults aged 20–44 (n = 4,747) constituted 24.2%, 25.6% and 50.3% of the respondents, respectively. The clinical part (including skin prick tests, an assay of Timothy grass-specific IgE), was attended by 24% of the respondents. Data from 6-year pollen monitoring served to characterize birch and grass pollen seasons.ResultsWe found insignificant negative associations between the duration of birch pollen season and the prevalence of declared allergic rhinitis and asthma during the season across all age groups. There were insignificant inverse associations between the number of days with above-threshold and high grass pollen concentrations, total grass pollen count and the prevalence of declared allergic rhinitis and asthma during the season across all age groups. Associations noted in the clinical part were also non-significant; however, these trends were not uniform across the age groups.ConclusionsOur findings do not confirm the hypothesis of a positive association between pollen exposure and the prevalence of allergic rhinitis and asthma.

A study on the spatial and temporal variability in airborne Betula pollen concentration in five cities in Poland using multivariate analyses

During the spring period, Betula pollen is the main cause of inhalant allergies in Poland and therefore it is important to monitor and forecast airborne pollen concentrations of this taxon. This study conducted a comparative analysis of the basic characteristics of Betula pollen seasons at the regional scale. The study was carried out from 2001 to 2016 in five cities in Poland: Lublin, Warsaw, Cracow, Sosnowiec, and Szczecin. To find the attributes of birch pollen seasons that mostly differentiated the individual cities, a general discriminant analysis (GDA) was performed, while a principal component analysis (PCA) allowed us to reduce the data space and present a scatterplot of PCA scores in order to compare pollen seasons in the individual cities. The contingency table was also analyzed to check whether there was a significant relationship between pollen counts in the studied years and cities. At most of the sites, biennial cycles of low and high pollen concentrations can be observed. Due to the high variation in seasons in each of these cities, two data groups were distinguished: Group 1 was composed of seasons with high pollen deposition (2001, 2003, 2006, 2008, 2010, 2012, 2014, 2016), and Group 2 comprising the other seasons. Multivariate analyses were performed on both these groups as well as in the entire dataset. End98, Peak Value, and Annual Total had the highest discriminant power. In Group 1, Warsaw and Sosnowiec differed the most in the investigated parameters, while Cracow and Szczecin differed the least. In both groups, most seasons with the highest pollen birch concentration were observed in Lublin, followed by Warsaw, while in Cracow, the number of such seasons was the smallest.

Pollination and pollen germination in common juniper (Juniperus communis: Cupressaceae)

Pollination and fertilization are the most important and responsible stages in sexual reproduction of coniferous plants. The period of high concentrations of juniper pollen in overhead during pollination period is no more than 4–6 hours and within one calendar day. This dependence remains invariable from year to year, and does not depend neither from weather conditions, nor the peculiarities of the place where juniper grows. Influence of external agents on dynamics of exudation of a juniper pollination droplet is studied. The duration of exudation and volume of secretory liquid exuded by tissues of ovules during the period of prescription in the juniper depend from presence of external agents on a surface of pollination droplet, their sizes and physical and chemical properties. The pollination droplet chemical compound is studied. In sugars composition of juniper pollination droplet there are only two monosaccharides: glucose and galactose. the amino acids composition is prevailed by arginine, aspartic and glutamic acids. The results of the studies confirm complex chemical composition and multifunctionality of juniper pollination droplet. The pollination mechanism of juniper is effective and selective. The morphological structure of pollen grains of juniper predetermines the processes of pollen germination at early stages. The hydrophilic capsule, formed pollen hydration, promotes to exine rupture and shedding. This capsule remains until the fertilization. The distal tip of pollen tube remains in itduring all time of its growth. In culture in vitro development of pollen tubes of juniper proceeds non-uniformly. At definition of juniper pollen viability it is necessary to consider a stage of pollen tubes development.

Are the profilins an important component in the atmosphere? Ole e 2-like panallergen

The analysis of profilin Ole e 2 concentration and its relationship with pollen concentration was carried out in the atmosphere of Leon (located in north-western of Spain) during 3 years. Moreover, we have studied the influence of some atmospheric pollutants and climatic parameters using Spearman rank correlation and principal components analysis. As a result, the presence in the atmosphere of Ole e 2 is demonstrated. We can observe that in April and until mid-May, the peaks of Ole e 2 correspond to the high concentrations of pollen from various tree plants, such as Quercus, Populus, Betula, Cupressaceae. From this date until the middle of June, where the presence of this profilin begins to be scarce in the air, the concentration of Ole e 2 is linked to herbaceous plants: Rumex, Plantago and species of the family Poaceae. Statistical analysis showed that the factors of temperature get influenced the most in the presence of Ole e 2 in the atmosphere, followed by the relative humidity and precipitation. In our study, there was no clear correlation with atmospheric pollutants; however, an increase in NO2 and SO2 causes a decrease in profilin in the atmosphere.