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.

Expansion and aerobiology of Ambrosia artemisiifolia L. in Slovakia.

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 Kosice 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.