Aerosol measurement methods to quantify spore emissions from fungi and cryptogamic covers in the Amazon

Löbs, Nina; Barbosa, Cybelli G. G.; Brill, Sebastian; Walter, David; Ditas, Florian; Sá, Marta; Araújo, Alessandro; Oliveira, Luana Martins; Godoi, Ricardo H. M.; Wolff, Stefan; Piepenbring, Meike; Kesselmeier, J.; Artaxo, Paulo; Pöschl, Ulrich; Pöhlker, Christopher; Weber, Bettina

doi:10.5194/amt-13-153-2020

Cited by 16 publications

(14 citation statements)

References 53 publications

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“…Based on one distinct mode in their FBAP observations, Toprak and Schnaiter (2013) attributed their observations to a site-specific spore type. For the Hyytiälä site, Manninen et al (2014) suggest that fungal spores strongly contribute to PBAP numbers, based on spore counts. No dominant contributor to the FBAP concentrations has been identified at the Colorado site.…”

Section: Validation With Independent Datasets: Seasonal Cycle and Vermentioning

confidence: 99%

Drivers of the fungal spore bioaerosol budget: observational analysis and global modeling

et al. 2021

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Abstract. Bioaerosols are produced by biological processes and directly emitted into the atmosphere, where they contribute to ice nucleation and the formation of precipitation. Previous studies have suggested that fungal spores constitute a substantial portion of the atmospheric bioaerosol budget. However, our understanding of what controls the emission and burden of fungal spores on the global scale is limited. Here, we use a previously unexplored source of fungal spore count data from the American Academy of Allergy, Asthma, and Immunology (AAAAI) to gain insight into the drivers of their emissions. First, we derive emissions from observed concentrations at 66 stations by applying the boundary layer equilibrium assumption. We estimate an annual mean emission of 62 ± 31 m−2 s−1 across the USA. Based on these pseudo-observed emissions, we derive two models for fungal spore emissions at seasonal scales: a statistical model, which links fungal spore emissions to meteorological variables that show similar seasonal cycles (2 m specific humidity, leaf area index and friction velocity), and a population model, which describes the growth of fungi and the emission of their spores as a biological process that is driven by temperature and biomass density. Both models show better skill at reproducing the seasonal cycle in fungal spore emissions at the AAAAI stations than the model previously developed by Heald and Spracklen (2009) (referred to as HS09). We implement all three emissions models in the chemical transport model GEOS-Chem to evaluate global emissions and burden of fungal spore bioaerosol. We estimate annual global emissions of 3.7 and 3.4 Tg yr−1 for the statistical model and the population model, respectively, which is about an order of magnitude lower than the HS09 model. The global burden of the statistical and the population model is similarly an order of magnitude lower than that of the HS09 model. A comparison with independent datasets shows that the new models reproduce the seasonal cycle of fluorescent biological aerosol particle (FBAP) concentrations at two locations in Europe somewhat better than the HS09 model, although a quantitative comparison is hindered by the ambiguity in interpreting measurements of fluorescent particles. Observed vertical profiles of FBAP show that the convective transport of spores over source regions is captured well by GEOS-Chem, irrespective of which emission scheme is used. However, over the North Atlantic, far from significant spore sources, the model does not reproduce the vertical profiles. This points to the need for further exploration of the transport, cloud processing and wet removal of spores. In addition, more long-term observational datasets are needed to assess whether drivers of seasonal fungal spore emissions are similar across continents and biomes.

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Section: Validation With Independent Datasets: Seasonal Cycle and Vermentioning

confidence: 99%

Drivers of the fungal spore bioaerosol budget: observational analysis and global modeling

et al. 2021

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“…The Agaricomycetes read proportion is also enhanced in sample CY26 (∼ 73 % of Basidiomycota; ∼ 8.5 % of Fungi). The Agaricomycetes are wood-degrading fungi, and many of them form 200 fruiting bodies, which release spores in response to humidity changes (Zoberi, 1964;Elbert et al, 2007;Hassett et al, 2015;Löbs et al, 2020). Analysis of the InterPro matches revealed higher read counts for the allergen Alt 1 from Alternaria alternata (Dothideomycetes) for samples collected during and after the rainfall period (Table C1).…”

Section: Composition and Community Changes Of Fungi Viridiplantae And Metazoamentioning

confidence: 99%

Bioaerosols and atmospheric ice nuclei in a Mediterranean dryland: Community changes related to rainfall

Tang

Sánchez-Parra

Yordanova

et al. 2021

Preprint

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Abstract. Certain biological particles are highly efficient ice nuclei (IN), but the actual contribution of bioparticles to the pool of atmospheric IN and their relation to precipitation are not well characterized. We investigated the composition of bioaerosols, ice nucleation activity, and the effect of rainfall by metagenomic sequencing and freezing experiments of aerosol samples collected during the INUIT 2016 campaign in a rural dryland on the Eastern Mediterranean island Cyprus. Taxonomic analysis showed community changes related to rainfall. For the rain-affected samples, we found higher read proportions of fungi, in particular of Agaricomycetes, which are a class of fungi actively discharging their spores into the atmosphere in response to humidity changes. In contrast, the read proportions of bacteria were reduced, indicating an effective removal of bacteria by precipitation. Freezing experiments showed that the IN population in the investigated samples was influenced by both rainfall and dust events. For example, filtration and heat treatment of the samples collected during and immediately after rainfall yielded enhanced fractions of heat-sensitive IN in the size ranges larger than 5 μm and smaller than 0.1 μm, which were likely of biological origin (entire bioparticles and soluble macromolecular bio-IN). In contrast, samples collected in periods with dust events were dominated by heat-resistant IN active at lower temperatures, most likely mineral dust. The DNA analysis revealed low numbers of reads related to microorganisms that are known to be IN-active. This may reflect unknown sources of atmospheric bio-IN as well as the presence of cell-free IN macromolecules that do not contain DNA, in particular for sizes < 0.1 μm. The observed effects of rainfall on the composition of atmospheric bioaerosols and IN may influence the hydrological cycle (bioprecipitation cycle) as well as the health effects of air particulate matter (pathogens, allergens).

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“…Rainfall and the associated increase in humidity can lead to increased emission of biological aerosol particles (Heo et al, 2014;Wright et al, 2014;Rathnayake et al, 2017). For example, raindrops hitting leaf or soil surfaces can disperse bacteria and other bioparticles by splashing (Hirst, 1953;Madden, 1997;Gilet and Bourouiba, 2014;Perryman et al, 2014;Kim et al, 2019;Gregory et al, 1959;Joung et al, 2017). Furthermore, the increase in relative humidity can trigger the emission of fungal spores by active discharge mechanisms (Zoberi, 1964;Lacey, 1996;Elbert et al, 2007), and pollen grains can rupture under moist conditions, releasing sub-pollen particles (Taylor et al, 2002Taylor and Jonsson, 2004;Miguel et al, 2006;Steiner et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Bioaerosols and atmospheric ice nuclei in a Mediterranean dryland: community changes related to rainfall

et al. 2022

Self Cite

View full text Add to dashboard Cite

Abstract. Certain biological particles are highly efficient ice nuclei (IN), but the actual contribution of bioparticles to the pool of atmospheric IN and their relation to precipitation are not well characterized. We investigated the composition of bioaerosols, ice nucleation activity, and the effect of rainfall by metagenomic sequencing and freezing experiments of aerosol samples collected during the INUIT 2016 campaign in a rural dryland on the eastern Mediterranean island of Cyprus. Taxonomic analysis showed community changes related to rainfall. For the rain-affected samples, we found higher read proportions of fungi, particularly of Agaricomycetes, which are a class of fungi that actively discharge their spores into the atmosphere in response to humidity changes. In contrast, the read proportions of bacteria were reduced, indicating an effective removal of bacteria by precipitation. Freezing experiments showed that the IN population in the investigated samples was influenced by both rainfall and dust events. For example, filtration and heat treatment of the samples collected during and immediately after rainfall yielded enhanced fractions of heat-sensitive IN in the size ranges larger than 5 µm and smaller than 0.1 µm, which were likely of biological origin (entire bioparticles and soluble macromolecular bio-IN). In contrast, samples collected in periods with dust events were dominated by heat-resistant IN active at lower temperatures, most likely mineral dust. The DNA analysis revealed low numbers of reads related to microorganisms that are known to be IN-active. This may reflect unknown sources of atmospheric bio-IN as well as the presence of cell-free IN macromolecules that do not contain DNA, in particular for sizes < 0.1 µm. The observed effects of rainfall on the composition of atmospheric bioaerosols and IN may influence the hydrological cycle (bioprecipitation cycle) as well as the health effects of air particulate matter (pathogens, allergens).

show abstract

Aerosol measurement methods to quantify spore emissions from fungi and cryptogamic covers in the Amazon

Cited by 16 publications

References 53 publications

Drivers of the fungal spore bioaerosol budget: observational analysis and global modeling

Drivers of the fungal spore bioaerosol budget: observational analysis and global modeling

Bioaerosols and atmospheric ice nuclei in a Mediterranean dryland: Community changes related to rainfall

Bioaerosols and atmospheric ice nuclei in a Mediterranean dryland: community changes related to rainfall

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