The Atacama Desert in northern Chile is often described as the driest place on Earth. With almost no rainfall, intense ultraviolet radiation, and extremely salty soils, parts of the region are so extreme that scientists often liken its arid environment to the surface of Mars.
And yet, remarkably, even despite the harsh surface conditions, a variety of organisms continue to survive below ground.
A recent study from the University of Cologne has revealed that microscopic worms known as nematodes form surprisingly diverse communities throughout the Atacama Desert. Published in Nature Communications, the research shows that underground biodiversity increases with increasing moisture, while elevation and temperature determine which nematode species can survive in different parts of the desert.
Life Beneath an Extreme Landscape
Nematodes are among the most common varieties of tiny lifeforms that are found in soils worldwide. These minuscule worms often play a crucial role in helping control microbes and are important for moving nutrients through the soil. They live in many places, from the deep sea to the Arctic. As a result, they are useful for studying how life adapts to harsh environments.
“Soils are important for the performance of an ecosystem, for example, for carbon storage and nutrient supply,” said Dr. Philipp Schiffer of the University of Cologne’s Institute of Zoology and a co-author of the study. “This is why understanding the organisms — not microbes, but multicellular animals — that live there is so important.”
Although the Atacama Desert has been studied for decades, the diversity of animals living in its soils remains poorly understood.
Studying Atacama’s “hidden” Lifeforms
The research team surveyed nematode populations across six different regions of the Atacama Desert to better understand how life persists in these extreme conditions. The sites spanned a range of environments, from moist, high-altitude areas with abundant vegetation to salty desert plains blasted by ultraviolet light, and even rare oases fed by fog.
The team collected soil samples from diverse habitats, including sand dunes, salt flats, riverbeds, and mountain slopes, to assess nematode biodiversity and population structure. Their analysis focused on both the variety of species present and the reproductive strategies used by nematodes in each setting.
Asexual Survival Strategies
The findings revealed clear differences in nematode communities across the Atacama. In the highest and most inhospitable regions, many species reproduce asexually through parthenogenesis, generating offspring without fertilization. This pattern supports the hypothesis that asexual reproduction provides an advantage in extreme environments, where finding mates can be challenging.
The study also found that nematode diversity was highest in areas with more moisture. Regions with greater rainfall supported a wider range of species, while temperature differences shaped which communities could survive in each area.
Fragile Ecosystems in a Changing Climate
The results suggest that stable soil ecosystems can exist even in extreme places, but these systems may be more fragile than previously believed. In some areas, the researchers found simpler food webs, showing that these ecosystems also have less ecological complexity.
“In some of the examined regions, simplified food webs indicate that these ecosystems are already damaged and may therefore be more susceptible to disruptions,” the researchers noted.
Understanding how organisms adapt to extreme environments could become increasingly important as climate change expands arid conditions across many parts of the planet.
“In light of increasing global aridity, which is affecting more and more regions worldwide, these results are becoming increasingly relevant,” Schiffer said.
The research demonstrates that basic ecological patterns, such as precipitation and altitude, continue to influence biodiversity even in some of the planet’s most extreme environments. The Atacama Desert continues to serve as a valuable natural laboratory for understanding how life endures at the limits of environmental tolerance.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds a Master of Business Administration, a Bachelor of Science in Business Administration, and a Data Analytics certification. His work combines analytical training with a focus on emerging science, aerospace, and astronomical research.