News

06.11.2025

New article published: 🌍 Temporal change of arsenic in Sargassum spp. biomass deposit: mass balance, speciation and microbial biotransformation pathways

🌊🧪🦠The decomposition of Sargassum washed ashore poses a significant environmental problem due to the release of arsenic (As). In a 120-day mesocosm experiment under natural conditions, the fate of As in biomass, leachate, and gas phases was investigated. Fresh Sargassum contained 85 mg As/kg (dry weight), mainly as AsIII. In the leachate, the As concentration was initially 10 mg/L and decreased to 1.5 mg/L after 90 days, with AsV dominating. Volatile arsenic compounds, especially trimethylarsine, were also released at an early stage. After 120 days, about 50% of the original arsenic had passed into the leachate, while 0.06‰ escaped into the atmosphere. Despite considerable mass loss, 55 mg As/kg remained in the residual biomass. The increasing bacterial diversity indicates a central role of microorganisms in As conversion. The measured values often exceed the French limits for hazardous waste.🦠🧪🌊
Link to paper (PDF, 7.9 MB)

28.10.2025

Guest Speaker Dr. Sylvain Bouchet

On the 28th of October 2025 have the chance to hear a talk about mercury (Hg) in African terrestrial ecosystems and the loss Hg from soils following deforestation. Dr. Sylvain Bouchet, scientist at the Federal Institute for Metrology and research associate at ETH Zurich, is an analytical and environmental chemist with special interest on the spciation of trace elements and questions related to their mobility, transformation and toxicity. He worked in France, Sweden and Bolivia to investigate the behavior of Hg in aquatic ecosystems, then joined Eawag and later ETH Zurich, where he broadened his research to other trace elements (Se, As, Cu) and expanded his focus on terrestrial environments, especially soils.

Guest Speaker Dr. Sylvain Bouchet (PDF, 96KB)

16.09.25

New Colloquium Program!

The Colloquium will take place on Tuesdays from September 16th to December 16th from 16h15 to 18h00. Interested people are welcome to attend in person in room 002 of the Institute of Geography (Hallerstrasse 12). For more information, please download the flyer. Looking forward to meeting you there!

Soil Science Colloquium Autumn Semester 2025 (PDF, 298KB)

06.09.2025

Night of Research - Nacht der Forschung 2025

What a night! - The Night of Research was a real success for us. It was a pleasure to observe the great interest in healthy soils and our methods from people outside of soil science. Many THANKS to everyone who helped organize it, and many THANKS to those who took the time to visit our booth. 🌃✨🍀

Ursina Morgenthaler (PhD student in Soil Science) was honored to be part of the video campaign for the Night of Research – an event that brings research at the University of Bern to life for all ages. In the video, she talks about our research and what we offer at the NdF. However, as a woman in a STEM field, it is also important to her to appear in public and thus create more visibility for women in research. We would be delighted if you would stop by the Soil Science Unit University of Bern booth!

26.08.2025

Congratulations Dominik!

🎉🥳🎉🥳 On Tuesday, 26.08.2025, Dominik successfully defended his MSc thesis entitled "Geogenic Arsenic in Swiss Rice Paddies". Congratulations from the Soil Science group, dear Dominik, and all the best for your future endeavours! 🎉🥳🎉🥳

18.08.2025

New article published: 🌍 New insights into Antimony (Sb) mobility in soils under changing climate conditions

Antimony (Sb) is an emerging contaminant of concern in shooting range soils, but its behavior under future climate conditions is still unclear. In a 28-day microcosm experiment, it has been studied how temperature and flooding influence Sb release from two contrasting soils, analyzing both dissolved and colloidal fractions. 🔎 Key findings: • Microbial biomass strongly controlled Sb release. • Higher temperatures reduced Sb release in the less contaminated, microbially rich soil, but increased it in the more contaminated, microbially poor soil—driven by temperature effects on microbially mediated redox processes. • 13–36% of Sb in pore water occurred as colloids, including organic colloids/Sb microcrystals (~2.5 nm) and mineral nanoparticles (15–20 nm). ⚡ Why this matters: This study shows how microbes and redox dynamics shape Sb mobility and highlights the importance of colloidal transport under changing climate conditions, pointing to the need for further research on temperature effects.

Link to paper (PDF, 4.6 MB)

11.08.2025

Anerkennung hervorragender Leistungen in der Lehre (ALL) - Recognition of outstanding achievements in teaching

Congratulations to the group leader Prof. Dr. Adrien Mestrot! 🎉👏🎊 The "Seminar in Soil Science" course has been nominated for the "Recognition of Excellence in Teaching (ALL)" award based on a particularly positive evaluation result. In today's world, where education and knowledge are of crucial importance, lecturers play a central role. They not only impart knowledge but also act as mentors who inspire, encourage, and support students. Outstanding courses can have a lasting impact on students' lives and professional careers. With this award, the university recognizes and honors its lecturers' commitment to outstanding teaching. ALL contributes to improving teaching quality, fostering appreciation for excellent teaching, and advancing the development of good teaching at the University of Bern as a whole. Furthermore, it provides mid-level faculty, in particular, with the opportunity to distinguish themselves in teaching.

18.06.2025

Mercury in our food – what does this mean for our health? 🐟🌿

In the current NZZ article on mercury contamination in food, Prof. Dr. Adrien Mestrot (Soil Science Group, University of Bern) assesses the risks: "The mercury [...] mostly remains bound to the soil and cannot be absorbed by the roots of plants." The soil science department at the University of Bern is actively researching mercury in the environment and nutrition – from its entry into soils to its conversion into toxic methylmercury.

05.05.2025

🌍 Trace elements in the atmosphere – an underestimated part of the biogeochemical cycle

Our research group studies the environmental pathways of trace elements – particularly their transfer from soil to other environmental compartments. A previously under-researched aspect of this cycle is bio volatilization by microorganisms, which releases trace elements such as arsenic and antimony into the atmosphere. We have been measuring emissions of arsenic and antimony compounds from soils for over 15 years. To further expand this research, we are now working on the Jungfraujoch with the goal of detecting volatile arsenic and antimony compounds in the atmosphere – in gaseous form, as particles on filters, and in snow. 🎯 Our goal: We want to find out whether these compounds also occur in higher atmospheric layers and in which chemical forms. These atmospheric trace elements can return to soils and water bodies through wet and dry deposition – thus completing their cycle. 🔬 Through this work, we aim to gain a deeper understanding of the dynamics of arsenic and antimony – from the soil, through the air, and back into the environment.

22.04.2025

Visit to the Federal Office for Metrology

The Swiss Federal Institute of Metrology METAS is the federal competence center for all matters relating to measurement, measuring instruments and measuring procedures. It is the national metrology institute of Switzerland. As such, its mission is to ensure that measurements can be made in Switzerland with the accuracy required for the needs of industry, research and administration. METAS covers a wide range of specialist areas, it is also the Reference Laboratory for Chemical Elements and Nitrogen Compounds in Foodstuffs which directly relates to our research. It is important for us to see and understand what we rely on in our daily work: accurate measuring instruments and reliable constants.

10.04.2025

New article published: Mercury Accumulation and Biomagnification in the Barn Owl (Tyto alba) Food Chain

Mercury (Hg) accumulation and biomagnification in the barn owl (Tyto alba) food chain were studied across three trophic levels: soil and moss, small mammal fur from pellets, and barn owl feathers. Spatial analysis showed regional Hg variation, with the highest concentrations in feathers (170 μg/kg) and fur (150 μg/kg), followed by soil (63 μg/kg). Bioaccumulation and biomagnification factors indicated increasing Hg through the food chain. Methylmercury made up most Hg in feathers. Diet strongly influenced Hg levels, with omnivorous prey causing higher fur concentrations than herbivorous prey. Results underscore the role of diet in mercury exposure and its use in ecological monitoring.

Link to paper (PDF, 1.2 MB)

04.04.2025

New article released: Pesticide contamination in indoor home dust: A pilot study of non-occupational exposure in Argentina

Pesticide use is increasing globally, and Argentina ranks fifth. This study examined indoor dust from 48 urban homes in Argentina’s Pampas Region, detecting 41 of 49 targeted pesticides, including banned substances and agricultural-only chemicals like glyphosate and atrazine. Some residues exceeded 1,000 μg/kg, and up to 32 compounds were found per sample. Despite being non-agricultural homes, contamination was linked to behaviors like wearing shoes indoors, pet ownership, flea treatments, and indirect occupational exposure. Results highlight the widespread presence of pesticides in residential environments and underscore the need for better monitoring and research on long-term exposure and health risks.

Link to paper (PDF, 1.5 MB)

03.04.2025

New paper published: ORDNA: Deep-learning-based ordination for raw environmental DNA samples

Environmental DNA (eDNA) metabarcoding aids biodiversity monitoring but poses challenges for traditional data analysis. ORDNA (ORDination via Deep Neural Algorithm) is presented, a deep learning method that directly processes raw eDNA sequences, avoiding biased bioinformatic steps. Using contrastive self-supervised learning (triplet loss), ORDNA generates two-dimensional representations of eDNA samples based on read composition. Applied to four diverse datasets, ORDNA outperformed conventional ordination methods in visualizing ecological patterns. This highlights the power of deep learning in eDNA analysis, offering a more accurate, efficient approach to understanding biodiversity and ecosystem health through non-invasive sampling techniques.

Link to paper (PDF, 1.7 MB)

19.02.25

New Colloquium Program!

The Colloquium will take place on Tuesdays from February 19th to May 30th from 16h15 to 18h00. Interested people are welcome to attend in person in room 116 of the Uni Mittelstrasse (Mittelstrasse 43). For more information, please download the flyer. Looking forward to meeting you there!

Soil Science Colloquium Spring Semester 2025 (PDF, 377KB)

11.02.2025

Congratulations Luzia!

On Tuesday, 11.02.2025, Luzia successfully defended her MSc thesis entitled "Impacts of war– Contamination of soils in Ukraine in and around craters with potentially toxic trace elements". Congratulations from the Soil Science group, dear Luzia, and all the best for your future endeavours!

16.01.2025

Congratulations Sinh!

On January 16th, Sinh successfully defended his master's thesis entitled "A lysimeter field experiment to investigate microplastic transport through preferential flow paths in agricultural soils in Switzerland.". Congratulations Sinh and all the best for your future endeavours!

29.11.2024

New article published: Shift of the ecosystem nitrogen cycle from open to closed within a century along a glacial retreat chronosequence at Mount Gongga, southwest China

This study investigates the shift in the nitrogen (N) cycle during primary succession along a glacial retreat chronosequence at Mount Gongga, southwest China. By assessing biological nitrogen fixation, ammonification rates, and nitrogen retention through 15N tracer experiments, the research tracks how nitrogen cycling evolves from open to closed over a century. The findings show that nitrogen accumulation increases rapidly, and over time, the ecosystem shifts toward tighter N cycling, with minimal nitrification in older stages of succession, reflecting a mature system.

Link to paper (PDF, 1.6 MB)

17.11.2024

New article published: Perspectives on using peat records to reconstruct past atmospheric Hg levels

This article examines the potential of peatlands as valuable archives for reconstructing past atmospheric mercury (Hg) levels. As human activities have significantly increased Hg emissions, understanding regional variations in pollution is crucial. Peatlands, with their preserved records, can provide insights into past Hg cycling. This perspective highlights the role of peat vegetation and productivity in Hg sequestration and offers recommendations for improving the use of peat cores to track Hg levels over time, aiding global Hg cycle studies and evaluating mitigation efforts.

Link to paper (PDF, 1.9 MB)

30.10.2024

New article on methodology released: All black: a microplastic extraction combined with colour-based analysis allows identifcation and characterisation of tire wear particles (TWP) in soils

Tire wear particles (TWP) are a major source of microplastics in the environment, yet reliable data on their concentration and characteristics remain scarce. This article presents a novel method for extracting and identifying TWPs from soil, combining color-based analysis with machine learning to distinguish them from other black particles like charcoal. The approach offers high recovery rates and accurate results, allowing for detailed studies of TWP concentrations in highway-adjacent soils, with potential applications in addressing knowledge gaps in environmental microplastic research.

Link to paper (PDF, 1.6 MB)

28.10.2024

New paper published: Marine and terrestrial contributions to atmospheric deposition fluxes of methylated arsenic species

A new study explores the atmospheric deposition of methylated arsenic species, a toxic element from both natural and anthropogenic sources. The research, conducted at the Pic du Midi Observatory in France, reveals significant levels of methylated arsenic in precipitation, cloud water, and aerosols under free tropospheric conditions, indicating long-range transport. By identifying terrestrial and marine sources, the study highlights the importance of atmospheric deposition as a potentially overlooked contributor to bioavailable methylated arsenic in soils, impacting plant uptake and environmental health.

Link to paper (PDF, 1.6 MB)

 

Older news posts can be found in our News Archive.