Between March 17 and March 29, 2026, an interdisciplinary team of scientists from the Critical Zone cluster (subprojects B04, C04, C09, CZ02 and CZ03) conducted a sampling campaign in the Atacama Desert. Several parts of the field campaign were accompanied by members of the science communication team (subproject Z07).
The scientific team included professors Christine Heim (Geobiology, University of Cologne), Daniel Herwartz (Sediment and Isotope Geology, Ruhr University Bochum) and Patrick Fink (General Ecology, University of Cologne), postdoctoral researchers Ramona Mörchen (University Bonn), Tarja Hoffmeyer and Isabel Prater (both University of Cologne), and PhD students Mara Hochstein, Katrin Morr, Mayuri Rabha (all University of Cologne) and Jonas Schrodt (Ruhr University Bochum). The science communication team was represented by Prof. Annette Scheersoi, Dr. Julian Kokott and PhD student Alexander Weiss Aparicio (all University Bonn).
Mayuri Rabha and Ramona Mörchen continued their complementary sampling of surface crusts and sediments along aridity transects, building on work they initiated farther north during the previous year. Their research focuses on the composition of organic matter and microbial communities and the strategies by which microorganisms adapt to aridity and how they interact with the mineral matrix.
Mara Hochstein and Katrin Morr concentrated on sampling different calcium sulfate crusts. One aim of their project is to identify potential biological agents involved in the transformation of gypsum into anhydrite. A second objective is to investigate the distribution of trace elements within these crusts as well as within the roots of endemic plant species.
Drawing on his expert eye and skills, Jonas Schrodt collected a variety of arthropod species using traps and targeted sampling techniques. These included beetles, silverfish relatives, flies, bees, ants and various other insects and arachnids. The collected specimens will be analyzed for their oxygen isotope ratios of their body water to determine their primary source of water. The aim of the sampling was to collect invertebrates representing different trophic and ecological niches within the same habitats, allowing for the reconstruction of parts of the food web and water cycling pathways.
The first week of the campaign was dedicated to sampling in the area of San Pedro de Atacama and the Salar de Atacama. The team also explored potential sampling sites in and around several lagunas towards the Andes for future studies. During the second week, the group split. While the biologists Patrick Fink and Tarja Hoffmeyer from the new subproject CZ03 took samples in the Salar de Huasco, the geoscientists continued their sampling campaign along the Paposo transect south of Antofagasta.
The biologists focused on lagunas – salt lakes characterized by high concentrations of minerals resulting from intense evaporation and limited precipitation. Together with Assistant Professor Pablo Aguilar (Universidad de Antofagasta), they collected microbial mat samples along a salinity gradient extending from a freshwater source into a laguna within the Salar de Huasco. The aim of this work is to unravel how salinity impacts the functional capacities of the microbial communities that form those mats, particularly with respect to salinity adaptation and mineralization processes.
An integral part of this field campaign was the interdisciplinary exchange of ideas and the development of further collaborations. The success of the expedition was made possible in large part through the invaluable support of our Chilean partners. We are especially grateful to Professor Eduardo Campos from the Universidad Catolica del Norte in Antofagasta who supported us in many ways and to Assistant Professor Pablo Aguilar from the Universidad de Antofagasta who supported the sampling at the Salar de Huasco at every level.
This fascinating fieldwork will be brought to the wider public as part of the CRC’s science communication subproject. Annette Scheersoi, Julian Kokott and Alex Weiss Aparicio documented many different aspects of the fieldwork and also interviewed the scientists about their research and motivation. Overall, the collected materials—several hours of video, more than 1,000 photos and a variety of samples and tools—will be a valuable resource for curating the upcoming exhibitions and accompanying science-communication formats in Chile, Namibia, and Germany. During the trip, the team secured the Regional Museum of Iquique and the Cultural Center of Antofagasta as key cooperation partners in Chile.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
