Soil Community in Atacama Desert Survives on Fog

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The northern stretches of Chile in South America are home to some of the harshest climate habitats on the planet. The people, plants and animals that live in this arid region are subject to vast temperature changes, a lack of water, and tough growing conditions. However, despite the looks of things, there is a surprising amount of life happening in this unique desert region.

Scientists have discovered new methods that allow certain plants and animals to survive in Chile’s Atacama Desert. Lichens, fungi, and algaes sit on top of the soil and ‘sip’ the moisture that comes in the form of fog. These hardy communities make their homes atop the small stones that make up the Atacama, and are able to photosynthesize with less than half of the water that other desert communities with similar composition need in order to thrive. 

Chile’s Fog Desert

Fog deserts are also known as fog oasis for their cycles of fog that blanket a region. While the fog may be infrequent, it can deposit enough moisture into the air to keep desert plants alive. One such fog desert is Chile’s Pan de Azucar National Park, which resides between Chile’s Pacific Ocean Coast and the Atacama Desert. Here, scientists have found a new kind of soil crust community unlike any other in the world.

The Atacama Desert, which normally receives only 1 to 3 millimeters of rain a year, had a rare snowfall in 2011.  Image: NASA, public domain.
The Atacama Desert, which normally receives only 1 to 3 millimeters of rain a year, had a rare snowfall in 2011. Image: NASA, public domain.

What is Grit-crust?

Scientists call this layer of life a ‘grit-crust,’ a biocenosis made up of lichens, algae, fungi, cyanobacteria, and mosses. Researchers are able to find areas where this grit-crust exists because of its unique black and white patches that appear on the surface of the soil. Rather than make their home directly on top of the soil, this grit-crust sits on top of small stones that blanket the Atacama Desert floor. 

Grit‐crust ecosystems. (a) Blackish and whitish patterns caused by the newly discovered ‘grit‐crust’ biocrust in the landscape of Las Lomitas in the National Park Pan de Azúcar, South Atacama Desert, Chile. (b) Close up of blackish appearing grits covered by various lichens and concatenated grit‐crust (c), each with a scale bar of 1 cm.  Images: Jung et al., 2019.
Grit‐crust ecosystems. (a) Blackish and whitish patterns caused by the newly discovered ‘grit‐crust’ biocrust in the landscape of Las Lomitas in the National Park Pan de Azúcar, South Atacama Desert, Chile. (b) Close up of blackish appearing grits covered by various lichens and concatenated grit‐crust (c), each with a scale bar of 1 cm. Images: Jung et al., 2019.

Also known as a biological soil crust or biocrust, these communities are made up of different species that all work symbiotically to survive in tough circumstances. Communities like this are estimated to cover about 12% of the Earth and produce oxygen through photosynthesis. Additionally, they change the environment around them by absorbing carbon and nitrogen into the ground around them. The fungi are able to insert their tubular growth structures (hyphae) into the spaces between the rocks and soil in the Atacama and grow and shrink with the fog that comes in. This process, over time, is the only known way of creating soil in the desert. 

Continuing Research on Life in the Desert

These lichens, fungi, and algae are yet another example of how life finds a way in the harshest of climates on Earth. Areas like the Atacama Desert are harsh but sensitive to change, especially through erosion. The small amount of binding that these microscopic communities maintain helps prevent desert erosion, in addition to producing oxygen. The discovery of this unique biocrust will allow scientists to begin looking at other fog deserts around the world to see if this community exists anywhere else, such as the Namib Desert in southern Africa. 

The Study

Jung, P., Baumann, K., Lehnert, L. W., Samolov, E., Achilles, S., Schermer, M., … & Karsten, U. (2020). Desert breath—How fog promotes a novel type of soil biocenosis, forming the coastal Atacama Desert’s living skin. Geobiology18(1), 113-124. https://doi.org/10.1111/gbi.12368


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A newly found Atacama Desert soil community survives on sips of fog. (2019, December 12). Retrieved from https://www.sciencenews.org/article/new-atacama-desert-soil-fungi-lichen-community-survives-fog-sips

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