Researchers have discovered thriving communities of tiny soil-dwelling nematodes in the Atacama Desert, one of the world's driest places. An international team led by the University of Cologne found that biodiversity increases with moisture and altitude, with many species reproducing asexually in extreme zones. The findings, published in Nature Communications, highlight the resilience of life in arid environments.
The Atacama Desert in Chile, often compared to polar deserts due to its extreme aridity, high salt levels, and temperature swings, hosts surprising diversity among nematodes. These microscopic worms, studied by specialists in zoology, ecology, and botany, play key roles in soil ecosystems by controlling bacterial populations, aiding nutrient cycling, and indicating soil health.
The research, part of the Collaborative Research Centre 1211 "Earth -- Evolution at the Dry Limit," examined six regions with varying conditions, including higher elevations with more moisture, saline zones under intense UV radiation, and fog-fed oases. Soil samples from sand dunes, salt flats, riverbeds, and mountains revealed clear patterns: nematode biodiversity rises with precipitation, while altitude and temperature shape species survival.
In higher elevations, asexual reproduction—known as parthenogenesis—dominates, supporting the idea that it aids survival in harsh settings. "Soils are important for the performance of an ecosystem, for example for carbon storage and nutrient supply. This is why understanding the organisms, i.e. not microbes, but multicellular animals, that live there is so important," said Dr. Philipp Schiffer from the University of Cologne's Institute of Zoology.
Data on such extreme ecosystems remains scarce, the study notes. It also points to vulnerabilities: some regions show simplified food webs, suggesting damage and heightened susceptibility to disruptions. "In light of increasing global aridity, which is affecting more and more regions worldwide, these results are becoming increasingly relevant," Schiffer added. The work underscores how environmental gradients influence biodiversity even in extremes, with implications for assessing climate change impacts on soil life.
The findings appear in Nature Communications under the title "Geographic distribution of nematodes in the Atacama is associated with elevation, climate gradients and parthenogenesis."
