Lifestyle dependent occurrence of airborne fungi

Abstract

Abstract. Fungi play important roles in the environment, agriculture, and human health. Most fungal species spread by winddriven dispersal of spores, determining their occurrence and distribution in different environments. The dynamics of airborne fungi and their dependence on lifestyle and environmental conditions, however, are not well characterized. 10Here, we categorize the fungi detected in coarse and fine aerosol samples from continental boundary layer air using a lifestyle classification scheme that differentiates whether the fungi are (A) primarily associated to herbaceous or woody plants and (B), whether they are saprophytic, plant pathogenic, or surface inhabitants."Herbaceous" fungi exhibit stronger seasonal variations and correlations with meteorological factors. We find two distinct clusters when viewing the distribution of the fungi between the coarse and fine size fractions. Pathogenic and surface-15 inhabiting herbaceous fungi are shifted towards the coarse size fraction, adapted to impaction on plant surfaces, while saprophytic fungi are shifted towards the fine fraction or are evenly distributed, adapted more to sedimentation and longer atmospheric residence times."Wood" fungi display sporadic occurrences, seen for most saprophytes, or year-round occurrences with seasonal to polycyclic peaks seen amongst pathogens. In comparison to herbaceous fungi they show weaker correlations with meteorological factors. 20They display more even coarse-fine distributions, which may be an adaptation to the calm conditions beneath the forest canopy.The differences reflect lifestyle-dependent sporulation strategies which may facilitate and improve the assessment and forecasting of the abundance and spread of pathogenic fungi and related issues such as crop protection in view of land-use and climate change.

Microbial composition in seasonal time series of free tropospheric air and precipitation reveals community separation

“…Seasonal variation and temporal vicinity of sample composition have been observed for near-surface airborne bacterial and fungal communities (Bowers et al 2013;Fahlgren et al 2010;Franzetti et al 2011;Pickersgill et al 2017), and even above PBL for bacteria (Bowers et al 2012). These observations are consistent with our data, which showed that there was no stable free troposphere air microbial community during the year of sampling at Mount Sonnblick, although a core microbiome could be identified consisting of 61 (11% of all air genera) bacterial and 8 fungal genera (3% of all fungal air genera).…”

“…The overall 18S rRNA gene abundance was highest in November together with the lowest 16S:18S ratio. Fungal occurrences are strongly coupled to seasons and meteorological factors, depending on their lifestyle and sporulation strategy, and usually show high variations in air and cloud water (Pickersgill et al 2017;Amato et al 2007a, b). In May the valley was completely covered by fresh snow (50 cm before sampling), and in November, the first snowfall on vegetation in the valley occurred on the day before sampling at the end of the growing season.…”

Beyond the planetary boundary layer: Bacterial and fungal vertical biogeography at Mount Sonnblick, Austria

“…Fungal abundances in air and cloud water generally show higher variation than bacteria due to their lifestyle-dependent dispersal and occurrence (Amato et al, 2007;Pickersgill et al, 2017). Plants are considered to be the biggest source of fungal spores to the air (Burge, 2002).…”

“…Many studies have investigated composition, abundance and variability of PBAs across a variety of ecosystems (Bowers et al, 2011;Cuthbertson et al, 2017;Griffin et al, 2010;Harding et al, 2011;Joung et al, 2017;Pearce et al, 2010). These processes might depend on emission sources of microorganisms, meteorological conditions such as precipitation, wind and humidity (Burrows, Butler, et al, 2009;Jones & Harrison, 2004;Joung et al, 2017), lifestyle, as has been demonstrated for fungi (Pickersgill et al, 2017), and vertical mixing of the atmosphere. Thus, little information exists about the dynamics that select the microorganisms that transit the PBL to reach the free troposphere (Womack et al, 2010).…”

“…Thus, little information exists about the dynamics that select the microorganisms that transit the PBL to reach the free troposphere (Womack et al, 2010). These processes might depend on emission sources of microorganisms, meteorological conditions such as precipitation, wind and humidity (Burrows, Butler, et al, 2009;Jones & Harrison, 2004;Joung et al, 2017), lifestyle, as has been demonstrated for fungi (Pickersgill et al, 2017), and vertical mixing of the atmosphere. We expected that the vertical distributions of bacteria and fungi would not be similarly affected due to differences in their size and lifestyle.…”