Representativeness of pollen traps: a review of the national pollen network of Switzerland Abstract The national pollen network of Switzerland was developed historically. Its 14 pollen traps were placed without considering their representativeness and spatial coverage. The plan for automation of the network gives the motivation for reviewing the network design and to determine the importance and representativeness of each existing monitoring station. Similarities and dissimilarities of the 20-year-long pollen data series (1997–2016) were studied by cluster analysis. Focus was put on the daily course of the pollen season of the seven most important allergenic pollen taxa. The cluster analysis based on correlations of daily pollen concentrations revealed a group of seven similar stations on the Swiss Plateau which differ clearly from the seven stations outside this region. The stations on the Swiss Plateau can be clustered into two subregions, a western and an eastern one. Their correlation coefficients are linearly correlated with distance (from 50 to 300 km). The pattern of the clusters is in good agreement with the division of Switzerland in bioclimatic regions.

Preliminary study of the atmospheric pollen in Sierra de las Nieves Natural Park (Southern Spain) Abstract Sierra de las Nieves is a Natural Park and a Biosphere Reserve located in Southern Spain. This protected area has a high diversity of ecosystems with abundant endangered species which has led to be proposed as a National Park. In January 2018, a pollen trap was installed inside this Natural Park in order to determine the atmospheric pollen behaviour of the main taxa registered during a whole year. Additionally, the results were compared with those registered in the urban and rural stations of Malaga and Ronda, respectively, during the same period. The samplings were made by means of a Hirst-type volumetric pollen trap, and the samples obtained were mounted and counted according to the methodology proposed by the Spanish Aerobiology Network. The highest amount and diversity of atmospheric pollen in the Natural Park was detected during the spring months. Statistical significant differences were found, regarding daily total pollen concentrations, between Sierra de las Nieves (Natural Park) and Malaga (urban city), and between Ronda (rural city) and Malaga. These differences were particularly detected for some pollen types such as Quercus. In general, the start of the main pollen season and the maximum concentration peak of the major pollen types occurred later in Sierra de las Nieves than in Ronda and Malaga. The qualitative and quantitative differences between Sierra de las Nieves and the others nearby locations can be explained by the differences in land use, altitude, climatic characteristics, as well as the distance between the aerobiological stations and the pollen emission sources.

The use of cyclohexane as new solvent for airborne pollen sampling Abstract Almost all the aerobiological networks used the non-volatile silicone fluid as a capture medium adhesive on the Melinex tape of Hirst-type volumetric samplers. This adhesive was prepared with carbon tetrachloride, considered as a carcinogenic agent. Since that, there is a spreading interest to find an alternative solvent for continuing the aerobiological sampling. In this study, we examined the impaction efficiency of the cyclohexane and carbon tetrachloride solvent, widely used in aerobiological studies. The results revealed that there is no significant difference between the two solvents and that cyclohexane can be used as a new solvent of the adhesive substance for airborne pollen sampling.

The effects of cold stress on cypress pollen intine permeability

Assessment between Platanus pollen and Pla a 1 allergen in two cities of North-western Iberian Peninsula Abstract Platanus pollen is considered as a major cause of pollinosis in many southern European cities. This tree is commonly used in parks, avenues and gardens as ornamental species. The flowering period is short and abrupt between March and April, since this tree is characterized by having fast and explosive blooming process. This fact induces an important public health problem when Platanus bloom. The objective of the study is to evaluate the pollen and allergen concentration in two cities in the north-west of the Iberian Peninsula, Porto (Portugal) and Ourense (Spain), and analyse how weather parameters and environmental pollutants can affect the patterns of pollen and allergen airborne distribution. The pollen sampling was conducted, during 2018, using a Hirst volumetric sampler, and Pla a 1 aeroallergen was collected using a Burkard multivial cyclone sampler. The pollen counting was obtained following the Spanish Aerobiology Network methodology. Aeroallergens were quantified by ELISA method using a Pla a 1-specific antibody. Platanus pollen concentrations are seven times lower in the Porto atmosphere than in Ourense, but the Pla a 1 content is only 2 times higher in Ourense city. These differences can be explained by the influence of air pollutants in plants and meteorological factors. Platanus airborne pollen and Pla a 1 aeroallergen were correlated with some meteorological parameters, namely temperature, rainfall and relative humidity, and with atmospheric pollutants such as NO2 and O3. The results suggest the existence of different allergenic activities in the atmosphere of both cities.

On possibilities of assimilation of near-real-time pollen data by atmospheric composition models Abstract Assimilation of pollen observations for increasing accuracy of the deterministic model forecast and reanalysis faces several roadblocks. The most-evident problem today is the long delay of the data because of the manual character of the observations. Automatic monitors are about to eliminate this issue but more are on the way. This paper shows that the classical assimilation of the model state, i.e. pollen concentrations, has very little effect on the forecasts. Due to short relaxation time of the system, the updates generated by the assimilation are forgotten within a few hours. In a search of approaches with a longer-lasting impact, a numerical experiment is conducted assimilating the total seasonal pollen emission, which controls the overall season severity. It turned out to be a prominent example of parameters affecting the model predictions over the long period—in the retrospective simulations. It remains to be demonstrated that this parameter can substantially benefit from assimilation of the near-real-time data that are becoming available from the automatic pollen monitors.

Analysis of the airborne fungal spores present in the atmosphere of Salamanca (MW Spain): a preliminary survey Abstract In this paper, we expose a preliminary study of the airborne fungal spore content in the atmosphere of Salamanca City including a fungal spore calendar. Sampling was carried out between February 2014 and February 2016, and along these 2 years of monitoring Cladosporium was the most abundant type followed by Aspergillus/Penicillium, both present from January to December. The peaks of diversity and abundance were established in two well-defined seasons focused on autumn (especially basidiomycota) and late spring. Others, like Cladosporium and Alternaria, called the dry spore types, had their maximum during summer. According to the intradiurnal pattern, the results were very similar for the spore types, except for Agaricus, Coprinus and Periconia that showed a nocturnal release pattern. The meteorological factors that had a clearly influence on the spore distribution were temperature, in the case of the dry spore types, and relative humidity in the case of wet air spores like Agaricus and Coprinus both basidiomycetes.

A comprehensive mycofloral diversity of pedosphere, phyllosphere and aerosphere of Som. ( Persea bombycina Kost.) in lower Brahmaputra valley of Assam Abstract Muga silkworm is endemic to North-East India. The quality of primary host plant, i.e. Som. (Persea bombycina Kost.), greatly affects the quality of cocoon and silk production. Som is susceptible to different foliar diseases caused by fungi, which can reduce the yield of leaf from 13.8 to 41.6% annually. So, a comprehensive mycofloral study of the host plant is important to forecast future diseases and design different disease management procedures. This study has been done for a period of 2 years from 2014 to 2016 in Goalpara district of Assam, India. Mycoflora of pedosphere (rhizosphere and non-rhizosphere), phyllosphere and aerosphere were identified and correlated with the seasonal variation. The rhizosphere, air and phylloplane were dominated by Rhizopus stolonifer (22.13%; 15.08%; 24.01%), while Aspergillus niger (12.63%) dominated non-rhizospheric soil. In summer, soil was majorly dominated by A. niger, Aspergillus fumigatus and Curvularia lunata, while R. stolonifer, Aspergillus clavatus and Penicillium chrysogenum dominated the winter soil. Pestalotiopsis disseminata is one of the major pathogens of Som and was found highest in aerosphere followed by phyllosphere. Temperature between 25 and 28 °C with 70–80% of relative humidity favours P. disseminata. This study provides a deep insight into the fungal diversity of Som with respect to pedosphere, aerosphere and phyllosphere, and this knowledge can be used to better select the plantation area and design different disease management strategies to sustain and proliferate the industry for socioeconomic development and to conserve its cultural essence.

The variability of pollen concentrations at two stations in the city of Wrocław in Poland Abstract The aim of the study was to investigate the variability of Alnus and Corylus pollen concentrations at two stations located in the city of Wrocław, Poland—one at the city centre and the other 4 km from the city centre. Our goal was to compare measurements from these stations in relation to meteorology and land cover. We used Spearman’s correlation coefficient to investigate any dependence between meteorological factors and pollen concentration. Additionally, to check the relation between the direction of inflow of air masses and pollen concentration, we calculated the backward trajectories using the HYSPLIT model. The results have shown that despite the short distance between the stations, the characteristic of the pollen season is different for both stations (i.a. date of start and end of pollen season, duration of the season). The Spearman’s correlation coefficient between relative humidity and air temperature and pollen concentration was found to be statistically significant. The backward trajectories calculated with HYSPLIT suggested a different origin of air masses between stations for high-concentration episodes in the case of Alnus. Our study has shown that analysis of meteorological conditions and influence of air transport into pollen concentration makes it possible to ascertain the reasons for differences in pollen level at these two stations, both of which are located in the same climatological domain. The study also shows that the aerobiological condition may change significantly over a short distance, which is a major challenge, for example, for pollen emission, transport, and concentration modelling.

Correspondence between tree pollen emissions sources and pollen content of the ambient air Abstract The article presents the findings, regarding the comparison between the pollen spectrum of the atmosphere in the area and the species composition of pollen emitting trees within the operating range of a Hirst-type volumetric air sampler. The research has revealed how local and transported pollen influence the pollen content of the atmospheric bioaerosol. Even though only a small number of birch trees grow in the area, its pollen proved to be prevalent in the pollen spectrum, while only an insignificant amount of Quercus pollen was detected due to the remoteness of its emission sources from the air sampler. Despite the fact that the highest number of trees in the immediate vicinity of the air sampler belong to the genus Tilia (linden), its pollen made up less than 1% of the pollen spectrum due to entomophily of these trees. Locations of tree pollen emission sources in the immediate vicinity of the Burkard spore and pollen trap were mapped out.