| 1. |
- Verstraeten, A., et al.
(författare)
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Effects of tree pollen on throughfall element fluxes in European forests
- 2023
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Ingår i: Biogeochemistry. - Göteborg : Springer. - 0168-2563 .- 1573-515X. ; 165:3, s. 311-325
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Tidskriftsartikel (refereegranskat)abstract
- The effects of tree pollen on precipitation chemistry are not fully understood and this can lead to misinterpretations of element deposition in European forests. We investigated the relationship between forest throughfall (TF) element fluxes and the Seasonal Pollen Integral (SPIn) using linear mixed-effects modelling (LME). TF was measured in 1990-2018 during the main pollen season (MPS, arbitrary two months) in 61 managed, mostly pure, even-aged Fagus, Quercus, Pinus, and Picea stands which are part of the ICP Forests Level II network. The SPIn for the dominant tree genus was observed at 56 aerobiological monitoring stations in nearby cities. The net contribution of pollen was estimated as the TF flux in the MPS minus the fluxes in the preceding and succeeding months. In stands of Fagus and Picea, two genera that do not form large amounts of flowers every year, TF fluxes of potassium (K+), ammonium-nitrogen (NH4+-N), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) showed a positive relationship with SPIn. However- for Fagus- a negative relationship was found between TF nitrate-nitrogen (NO3--N) fluxes and SPIn. For Quercus and Pinus, two genera producing many flowers each year, SPIn displayed limited variability and no clear association with TF element fluxes. Overall, pollen contributed on average 4.1-10.6% of the annual TF fluxes of K+ > DOC > DON > NH4+--N with the highest contribution in Quercus > Fagus > Pinus > Picea stands. Tree pollen appears to affect TF inorganic nitrogen fluxes both qualitatively and quantitatively, acting as a source of NH4+--N and a sink of NO3--N. Pollen appears to play a more complex role in nutrient cycling than previously thought.
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| 2. |
- Grewling, L., et al.
(författare)
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Outdoor airborne allergens: Characterization, behavior and monitoring in Europe
- 2023
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Ingår i: SCIENCE OF THE TOTAL ENVIRONMENT. - 0048-9697. ; 905
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Tidskriftsartikel (refereegranskat)abstract
- Aeroallergens or inhalant allergens, are proteins dispersed through the air and have the potential to induce allergic conditions such as rhinitis, conjunctivitis, and asthma. Outdoor aeroallergens are found predominantly in pollen grains and fungal spores, which are allergen carriers. Aeroallergens from pollen and fungi have seasonal emission patterns that correlate with plant pollination and fungal sporulation and are strongly associated with atmospheric weather conditions. They are released when allergen carriers come in contact with the respiratory system, e.g. the nasal mucosa. In addition, due to the rupture of allergen carriers, airborne allergen molecules may be released directly into the air in the form of micronic and submicronic particles (cytoplasmic debris, cell wall fragments, droplets etc.) or adhered onto other airborne particulate matter. Therefore, aeroallergen detection strategies must consider, in addition to the allergen carriers, the allergen molecules themselves. This review article aims to present the current knowledge on inhalant allergens in the outdoor environment, their structure, localization, and factors affecting their production, transformation, release or degradation. In addition, methods for collecting and quantifying aeroallergens are listed and thoroughly discussed. Finally, the knowledge gaps, challenges and implications associated with aeroallergen analysis are described.
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| 3. |
- Grewling, L., et al.
(författare)
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Variation in Artemisia pollen seasons in Central and Eastern Europe
- 2012
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 1873-2240 .- 0168-1923. ; 160, s. 48-59
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to address some gaps in current knowledge by studying temporal and spatial variations in Artemisia pollen counts (2000-2009) at 13 sites located in different biogeographical areas of Central and Eastern Europe. Analysis showed that start dates of Artemisia pollen seasons are greatly dependent on temperature during June and July, with hot summer temperatures having a tendency to delay summer flowering. However, this relationship is not linear and the rate at which seasons become later increases when mean minimum June-July temperatures reach a threshold of about 13 degrees C. No explanation for variations in pollen season intensity could be found. The geographical location or amount of urbanisation did not influence, either positively or negatively, the seasonal pollen index. Second peaks in Artemisia pollen seasons can be described as the pollen seasons of late flowering Artemisia species, and mainly occurred in the geographical area south of the Carpathian Mountains. These second peaks can significantly influence the seasonal pollen index, contributing over 50% to the season's total Artemisia pollen recorded at one site. (C) 2012 Elsevier B.V. All rights reserved.
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| 4. |
- Sikoparija, B., et al.
(författare)
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A mechanism for long distance transport of Ambrosia pollen from the Pannonian Plain
- 2013
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 0168-1923 .- 1873-2240. ; 180, s. 112-117
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Tidskriftsartikel (refereegranskat)abstract
- The pollen grains of ragweed are important aeroallergens that have the potential to be transported long distances through the air. The arrival of ragweed pollen in Nordic countries from the Pannonian Plain can occur when certain conditions are met, which this study aims to describe for the first time. Atmospheric ragweed pollen concentrations were collected at 16 pollen-monitoring sites. Other factors included in the analysis were the overall synoptic weather situation, surface wind speeds, wind direction and temperatures as well as examining regional scale orography and satellite observations. Hot and dry weather in source areas on the Pannonian Plain aid the release of ragweed pollen during the flowering season and result in the deep Planetary Boundary Layers needed to lift the pollen over the Carpathian Mountains to the north. Suitable synoptic conditions are also required for the pollen bearing air masses to move northward. These same conditions produce the jet-effect Kosava and orographic foehn winds that aid the release and dispersal of ragweed pollen and contribute towards its movement into Poland and beyond.
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