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This work is focused on mapping the aeropalynologic situation in the Bratislavan atmosphere. Volumetric pollen and pollen abortivity analyses were used for this purpose. The research comprised comparison of two pollen stations in this city between 2007 and 2011. Twice the number of pollen grains was measured at the U.V.Z. station compared to the D.B. station. Results showed that (1) the highest pollen totals for the period were recorded in the Urticaceae family, (2) April was the month with the highest pollen yield, and (3) species of the Urticaceae family had the longest pollen season of all studied taxa. The detected differences may have been due to various factors including; the very different habitats in the vicinity of the stations, slightly different climatic conditions, different evaluation methods and human factors. The ecogenotoxicity and mutagenicity of air at these selected city locations was evaluated and compared, and the effectiveness of our methods were verified by Betula pendula Roth . and Pinus sylvestris L . indicator species.

Introduction and objective. The invasive alien species Ambrosia artemisiifolia cause environmental, agronomical and medical problems in many regions of the world, including Slovakia. The purpose of this study was to survey the spread and distribution of this species in Slovakia and to analyse its airborne pollen pattern. Materials and methods. To evaluate the spatiotemporal dynamics of Ambrosia invasion in the territory of Slovakia, herbarium specimens, published databases and field investigations were considered. Aerobiological sampling was based on the analysis of pollen records at five aerobiological stations in Slovakia. For Bratislava and Banská Bystrica Monitoring stations, trends in Ambrosia pollen seasons were determined using Mann-Kendall test and Sen's slope estimator. Results. Since the first record of A. artemisiifolia in Slovakia, the number of its colonies and its spread rate has increased considerably, and the colonisation of this species has been successful mainly in the south-western part of the country. Highest airborne pollen counts were recorded in Nitra, Trnava and Bratislava Monitoring Stations situated in the areas most infested by A. artemisiifolia in Slovakia. However, high pollen counts were also noted in Banská Bystrica and Košice Monitoring Stations situated in areas where the source species was less abundant. During the study period, the number of days on which the pollen concentration exceeded the threshold of sensitivity increased significantly (+1.33 days/year) in Banská Bystrica, whereas the peak value decreased significantly (-13.37 pollen/year) in Bratislava. Conclusion. The number of the populations of A. artemisiifolia has increased considerably in recent years. Besides the most infested areas, high airborne pollen counts were also recorded in territories where the plant species was less abundant. During the study period, the intensity of Ambrosia pollen seasons decreased in Bratislava, probably due to changes in land-use practices, while the increasing trend in the pollen seasons intensity in Banská Bystrica mainly reflects the situation in the ragweed-infested remote areas due to long-range pollen transport. [ABSTRACT FROM AUTHOR]

Highlights: [•] We make a short overview of current ageing theories applied to plant organisms. [•] We study the possible reasons of longevity of some trees. [•] Tree mortality is mainly due to external influences, rather than to internal ageing. [•] Longevity of trees can depend on environmental conditions. [•] Single tree can behave as a population of modules, which can age individually. [ABSTRACT FROM AUTHOR]