Hypolithic Cyanobacteria Supported Mainly by Fog in the Coastal Range of the Atacama Desert

• Published in: Microbial ecology Vol. 61; no. 3; pp. 568 - 581
• Main Authors: Azúa-Bustos, Armando, González-Silva, Carlos, Mancilla, Rodrigo A., Salas, Loreto, Gómez-Silva, Benito, McKay, Christopher P., Vicuña, Rafael
• Format: Journal Article
• Language: English
• Published: New York Springer Science + Business Media 01.04.2011; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Archaea; Arid regions; Arid zones; Bacteria; Biodiversity; Biological and medical sciences; Biomedical and Life Sciences; Chile; classification; Coastal ranges; coasts; Colonization; community development; Cyanobacteria; Cyanobacteria - classification; Cyanobacteria - genetics; Cyanobacteria - growth & development; Desert Climate; Desert soils; Deserts; Ecology; ENVIRONMENTAL MICROBIOLOGY; Fog; Fundamental and applied biological sciences. Psychology; genetics; Geoecology/Natural Processes; growth & development; Heterotrophic bacteria; Humidity; latitude; Life Sciences; Microbial activity; microbial communities; Microbial Ecology; Microbiology; Microenvironments; Microorganisms; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nature Conservation; Photosynthesis; physiology; Positive feedback; Quartz; Rain; RNA, Ribosomal, 16S; RNA, Ribosomal, 16S - genetics; Rocks; Sensors; Soil Microbiology; Soil temperature regimes; Soil water; Stone; Temperature; Thermal conductivity; Water; Water - physiology; Water Quality/Water Pollution; Weather; Chile; Atacama Desert; Chile, Atacama Desert; Cyanobacterial Community; Quartz Stone; Soil Interface; Quartz Rock; Photosynthetic Photon Flux Density; Marine environment; Aquatic environment; Cyanobacteria; Bacteria; Ecology; Desert; Coastal zone
• ISSN: 0095-3628; 1432-184X; 1432-184X
• DOI: 10.1007/s00248-010-9784-5

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 ~ 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.