One of the driest places on Earth is teeming with hidden life

A Hostile Landscape with a Deceptive Appearance

The Atacama Desert, located in Chile, appears at first glance to be a dry, dusty, and barren landscape. This arid expanse is among the driest places on Earth, suggesting that no form of life could survive there.

A recent study has turned this perception on its head. Researchers have discovered that a teeming biological activity lies just beneath the soil’s surface, populated by tiny worms called nematodes.

An international team led by the University of Cologne studied these microscopic animals. The goal was to understand the mechanisms that allow them to survive in one of the harshest environments on the planet.

Six Extreme Environments Under the Microscope

Precipitation in the Atacama Desert remains extremely low. The soil there is salt-laden and, in some areas, even contains harmful elements such as arsenic.

Life finds a way despite these unforgiving conditions. The scientists examined six distinct areas across the desert, including high mountains, the shores of salt lakes, coastal fog oases, and vast sand dunes.

Each site has slightly different environmental characteristics. These subtle variations support the development of various types of organisms invisible to the naked eye.

The Fundamental Role of Microscopic Animals

Nematodes are earthworms so tiny that they remain invisible without a microscope. They play a crucial role in maintaining soil health.

Some of these worms feed on bacteria, others consume fungi or plants, and a handful act as predators by hunting other small organisms. The research team collected hundreds of soil samples and identified 36 different groups, or genera, of nematodes.

"Soils are important for ecosystem performance, for example in terms of carbon storage and nutrient supply. That’s why it’s so important to understand the organisms—not microbes, but multicellular animals—that live there,” said Dr. Philipp Schiffer. He added, regarding the context of the study: “Data on soils in extreme ecosystems such as the Atacama Desert are still scarce.”

Communities Shaped by Climate

The distribution of these worms varies greatly from one end of the desert to the other. While some families are found almost everywhere, others are confined to very specific areas.

Salt wetlands, known as salars, are home to communities distinct from those in the sand dunes, as are the fog oases near the coast, which sustain their own mix of species. In some areas, the soil food web appears simple and fragile, while it seems more stable elsewhere. This fragility suggests that certain parts of the desert are potentially vulnerable to damage caused by human activity or climate change.

Scientists have identified climate as the driving force behind this diversity. Areas receiving slightly more rainfall generally have a greater variety of nematode species. Temperature variations have a major impact: locations with large seasonal temperature differences are home to greater diversity.

A Reproductive Strategy Adapted to Extreme Conditions

The reproductive strategies of these microscopic animals have been carefully analyzed. Some nematodes reproduce sexually, requiring the presence of both males and females.

Others favor asexual reproduction, a process in which a single female can produce offspring without the involvement of a male. Scientists have observed that nematodes living at higher altitudes rely on this method more frequently.

Such a mechanism offers a vital advantage in extremely harsh environments, since a single individual can establish a new population without seeking a mate. This pattern supports a concept known as geographic parthenogenesis, which suggests that asexual reproduction is more common in extreme environments such as high mountains.

Valuable Lessons for a Drying Planet

Arid lands cover about 40 percent of the planet’s land surface. Climate change is expected to make many regions even drier in the future. The study of life in the Atacama Desert provides data to anticipate how organisms will respond to increasing droughts.

"Given the increasing global aridity, which is affecting more and more regions around the world, these findings are becoming increasingly relevant," Professor Schiffer emphasized. The researcher explained the implications of these findings: “Understanding how organisms adapt to extreme environments and which environmental factors drive their spread can help improve estimates of the ecological consequences of climate change.”

The Atacama Desert conceals entire ecosystems beneath its surface, where tiny worms survive and adapt in the face of adversity. This research, published in the journal Nature Communications, illustrates a flexibility and resilience of life far exceeding initial expectations.

According to the source: earth.com

One of the driest places on Earth is teeming with hidden life