Browsing by Author "Gomez-Silva, Benito"

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    Contribution of soil bacteria to the atmosphere across biomes
    (2023) Archer, Stephen D. J.; Lee, Kevin C.; Caruso, Tancredi; Alcami, Antonio; Araya, Jonathan G.; Cary, S. Craig; Cowan, Don A.; Etchebehere, Claudia; Gantsetseg, Batdelger; Gomez-Silva, Benito; Hartery, Sean; Hogg, Ian D.; Kansour, Mayada K.; Lawrence, Timothy; Lee, Charles K.; Lee, Patrick K. H.; Leopold, Matthias; Leung, Marcus H. Y.; Maki, Teruya; Mckay, Christopher P.; Al Mailem, Dina M.; Ramond, Jean-Baptiste; Rastrojo, Alberto; Santl-Temkiv, Tina; Sun, Henry J.; Tong, Xinzhao; Vandenbrink, Bryan; Warren-Rhodes, Kimberley A.; Pointing, Stephen B.
    The dispersion of microorganisms through the atmosphere is a continual and essential process that underpins biogeography and ecosystem development and function. Despite the ubiquity of atmospheric microorganisms globally, specific knowledge of the determinants of atmospheric microbial diversity at any given location remains unresolved. Here we describe bacterial diversity in the atmospheric boundary layer and underlying soil at twelve globally distributed locations encompassing all major biomes, and characterise the contribution of local and distant soils to the observed atmospheric community. Across biomes the diversity of bacteria in the atmosphere was negatively correlated with mean annual precipitation but positively correlated to mean annual temperature. We identified distinct non-randomly assembled atmosphere and soil communities from each location, and some broad trends persisted across biomes including the enrichment of desiccation and UV tolerant taxa in the atmospheric community. Source tracking revealed that local soils were more influential than distant soil sources in determining observed diversity in the atmosphere, with more emissive semi-arid and arid biomes contributing most to signatures from distant soil. Our findings highlight complexities in the atmospheric microbiota that are relevant to understanding regional and global ecosystem connectivity.
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    Hypolithic Cyanobacteria Supported Mainly by Fog in the Coastal Range of the Atacama Desert
    (2011) Azua-Bustos, Armando; Gonzalez-Silva, Carlos; Mancilla, Rodrigo A.; Salas, Loreto; Gomez-Silva, Benito; McKay, Christopher P.; Vicuna, Rafael
    The Atacama Desert is one of the driest places on Earth, with an arid core highly adverse to the development of hypolithic cyanobacteria. Previous work has shown that when rain levels fall below similar to 1 mm per year, colonization of suitable quartz stones falls to virtually zero. Here, we report that along the coast in these arid regions, complex associations of cyanobacteria, archaea, and heterotrophic bacteria inhabit the undersides of translucent quartz stones. Colonization rates in these areas, which receive virtually no rain but mainly fog, are significantly higher than those reported inland in the hyperarid zone at the same latitude. Here, hypolithic colonization rates can be up to 80%, with all quartz rocks over 20 g being colonized. This finding strongly suggests that hypolithic microbial communities thriving in the seaward face of the Coastal Range can survive with fog as the main regular source of moisture. A model is advanced where the development of the hypolithic communities under quartz stones relies on a positive feedback between fog availability and the higher thermal conductivity of the quartz rocks, which results in lower daytime temperatures at the quartz-soil interface microenvironment.