Géoblog

Category: Research at work

  • Algorithms made more “robust” by 13 Swiss and U.S. scientists to anticipate the future of the climate using AI     

    Algorithms made more “robust” by 13 Swiss and U.S. scientists to anticipate the future of the climate using AI     

    Machine learning algorithms, which are increasingly used in climate applications, are currently faced with a major problem: their difficulty in correctly predicting climate regimes for which they are not trained, thus generating uncertainties in projections. In a study published in the journal Science Advances, a team of researchers from the University of Lausanne and several American universities have revealed that, by transforming the data submitted to the algorithms using well-established physics principles, they can make them more “robust” for solving climate problems. This method has been successfully tested on three different atmospheric models. The implications of this finding go beyond climate science.

    Climate change projection is a generalization based on extrapolation from the recent past using physical models for past, present and future climates. However, current climate models face challenges related to the need to represent processes at scales smaller than the model grid size, thus generating uncertainties in projections. Although recent machine learning algorithms offer advantages for improving these process representations, they show a tendency to extrapolate poorly to climate regimes for which they are not trained.

    To overcome these limitations, the research team has proposed an innovative approach called “Climate-invariant Machine Learning”. This approach seeks to merge the physical understanding of climate models with the capabilities of machine learning algorithms to improve consistency, data efficiency, and generalization across diverse climate regimes. The results suggest that this integration of physical knowledge could strengthen the reliability of data-driven climate process models in the future.

    Seven points to better understand the key aspects of the study: 

    1. What climate applications are machine learning algorithms used for?

    Machine learning (ML) algorithms play a key role in enhancing climate models by simulating intricate processes such as storm dynamics, oceanic eddies, and cloud formation, which are costly with traditional methods. They’re pivotal in remote sensing for cloud detection and classification, and for downscaling global climate models to produce detailed local projections that better align with our observational record.

    2. Why have machine learning algorithms struggled with predicting climate change effects?

    Machine learning models, particularly neural networks, excel within the scope of their training data but can falter significantly with data that differ markedly from what they’ve seen before. This discrepancy arises because these models make implicit assumptions that may not hold true under novel climate conditions, leading to potential inaccuracies in projections outside their training regimes.

    3. What atmospheric models did the study focus on?

    The initial focus was on an “ocean world” model, a simplified representation of Earth’s climate system without continents, which helped identify and understand errors in extrapolation. The researchers progressed to more sophisticated, realistic atmospheric models that simulate the Earth’s climate dynamics. Integrating machine learning into these models is a promising venture to improve their realism, particularly for long-term climate projections, thereby contributing significantly to climate change adaptation and mitigation strategies.

    4. What does this mean beyond climate science?

    Beyond climate science, the methodology of the study offers a blueprint for incorporating physical principles into machine learning across various disciplines. By transforming the data using known physical invariances, the researchers can train ML models that work across various physical regimes despite only having been trained in a couple of them. This could work in any scientific domain with known invariances, e.g., in planetary science to create models generalizing across planets or in fluid dynamics to create models generalizing across flow regimes.

    5. How could this change climate science research?

    The study’s approach has the potential to advance climate science by enabling more accurate and generalizable process modeling. For example, machine learning models that have been trained on current climate data could, with appropriate physical adjustments, offer reliable projections for future climates. This breakthrough in generalization could lead to advancements in both weather forecasting and long-term climate projections.

    6. What are the next steps for this research?

    The groups which participated in this collaboration are exploring diverse avenues, including enhancing the generalizability of state-of-the-art data-driven weather forecasting models to future climates and incorporating these robust, climate-invariant modules into existing climate models. The goal is to keep pushing these data-driven models beyond their current limits, fostering a culture of rigorous and vigorous testing that could unearth new physical principles that extend beyond current observational capabilities.

    7. What’s the long-term impact of these findings and the potential of AI in climate science?

    The authors of the study anticipate these findings will foster deeper collaborations between the climate science and artificial intelligence communities. By encouraging the climate science community to view data-driven models not as a replacement but as an augmentation to traditional methodologies, and by promoting the development of AI techniques that are not just data-informed but also domain-aware, they anticipate a future where AI contributes significantly to advancing our understanding of climate processes, thereby enhancing collective ability to respond to the challenges posed by climate change.

    Additional information

    Tom Beucler, Pierre Gentine, Janni Yuval, Ankitesh Gupta, Liran Peng, Jerry Lin, Sungduk Yu, Stephan Rasp, Fiaz Ahmed, Paul A. O’Gorman, J. David Neelin, Nicholas J. Lutsko, Michael Pritchard, “Climate-Invariant Machine Learning”, Science Advances, 2024. [full text PDF]

  • Alpine glaciers will lose at least a third of their volume by 2050, whatever happens

    Alpine glaciers will lose at least a third of their volume by 2050, whatever happens

    The Aletsch glacier in 2009 {© UNIL, Guillaume Jouvet)

    Even if greenhouse gas emissions were to cease altogether, the volume of ice in the European Alps would fall by 34% by 2050. If the trend observed over the last 20 years continues at the same rate, however, almost half the volume of ice will be lost as has been demonstrated by scientists from UNIL in a new international study.

    By 2050, i.e. in 26 years’ time, we will have lost at least 34% of the volume of ice in the European Alps, even if global warming were to stop completely and immediately. This is the prediction of a new computer model developed by scientists from the Faculty of Geosciences and Environment at the University of Lausanne (UNIL), in collaboration with the University of Grenoble, ETHZ and the University of Zurich. In this scenario, developed using machine-learning algorithms and climate data, warming is stopped in 2022, but glaciers continue to suffer losses due to inertia in the climate system. This most optimistic of predictions is far from a realistic future scenario, however, as greenhouse gas emissions continue to rise worldwide.

    In reality, more than half the volume of ice will disappear

    Another more realistic projection from the study shows that, without drastic changes or measures, if the melting trend of the last 20 years continues, almost half (46%) of the Alps’ ice volume will actually have disappeared by 2050. This figure could even rise to 65%, if we extrapolate the data from the last ten years alone.

    2050: the near future

    Unlike traditional models, which project estimates for the end of the century, the new study, published in Geophysical Research Letters, considers the shorter term, making it easier to see the relevance in our own lifetimes and thus encouraging action. How old will our children be in 2050? Will there still be snow in 2038, when Switzerland may host the Olympic Games? These estimates are all the more important as the disappearance of kilometers of ice will have marked consequences for the population, infrastructure and water reserves. “The data used to build the scenarios stop in 2022, a year that was followed by an exceptionally hot summer. It is therefore likely that the situation will be even worse than the one we present”, states Samuel Cook, researcher at UNIL and first author of the study.

    Artificial intelligence boosts models

    Guillaume Jouvet, Institute of Earth Surface Dynamics

    The simulations were carried out using artificial-intelligence algorithms. The scientists used deep-learning methods to train their model to understand physical concepts, and fed it real climate and glaciological data. “Machine learning is revolutionizing the integration of complex data into our models. This essential step, previously notoriously complicated and computationally expensive, is now becoming more accurate and efficient”, explains Guillaume Jouvet, prof. at the FGSE and co-author of the study.

    The modelling was performed with the IGM model developed in UNIL ICEgroup.

    Source
  • How can we protect biodiversity? By improving monitoring of global genetic diversity

    How can we protect biodiversity? By improving monitoring of global genetic diversity

    The “Greek frog”, Rana graeca, is one of the species included in the analysis. Photo credit: Andreas Meyer

    Genetic diversity is crucial if species are to adapt to climate change. An international study co-conducted by UNIL researchers shows that current efforts to monitor genetic diversity in Europe are incomplete and insufficient. It proposes a novel approach for identifying and pinpointing important geographical areas on which to focus.

    • The genetic diversity of animals and plants is essential for their adaptation to climate change.
    • Current monitoring of this diversity is inadequate and could lead to the loss of important genetic variants.
    • A study co-directed by UNIL provides information on where to monitor genetic diversity in Europe.
    • It confirms that better monitoring of species and their genetic diversity is urgently needed internationally.

    Every living thing on our planet is distinguished from its fellow creatures by small differences in its hereditary material. So, when the environment changes and becomes unfavorable to populations of species (plants and animals), this genetic variability can enable them to adapt to the new conditions, rather than becoming extinct or having to migrate to other habitats. In simple terms, then, gene diversity is one of the keys to species survival. In 2022, the International Convention on Biological Diversity (CBD) placed increased emphasis on the need to protect the genetic diversity found in wild species, a fundamental component of biological diversity and one that has been generally neglected previously.

    Global warming is already putting a great deal of pressure on many species in Europe, particularly those having populations at the climatic limits of their range. The ability of species to resist greater heat or drought, as well as new species colonizing their environment, therefore determines their survival. It is in these borderline situations that it is most urgent to measure genetic diversity, in order to assess the ability of the species in question to persist.

    An international study co-directed by UNIL and published in Nature Ecology & Evolution has examined the monitoring of genetic diversity in Europe. Olivier Broennimann and Antoine Guisan, from the Faculty of Biology and Medicine and the Faculty of Geosciences and Environment, have made an essential contribution, developing a novel tool to identify geographical areas where genetic monitoring should be a priority. Their results show that efforts to monitor genetic diversity in Europe are incomplete and need to be supplemented.

    By analyzing all genetic monitoring programs in Europe, the study showed the geographic areas in which greater monitoring efforts are needed, mainly in southeastern Europe (Turkey and the Balkans). “Without better European monitoring of genetic diversity, we risk losing important genetic variants,” says Peter Pearman, lead author of the study and a former UNIL collaborator. Improved monitoring would make it possible to detect areas favorable to these variants, and to protect them in order to maintain the genetic diversity that is essential to the long-term survival of species. Some of these threatened species also provide invaluable services to humans, such as crop pollination, pest control, water purification and climate regulation.

    The study incorporated the efforts of 52 scientists who represent 60 universities and research institutes from 31 countries. The results suggest that European genetic diversity monitoring programs should be adapted systematically to span full environmental gradients, and to include all sensitive and high-biodiversity regions. In view of recent agreements to halt the decline in biodiversity, to which Switzerland is a signatory country, the study also points out that better monitoring of species in general, and their genetic diversity in particular, is urgently needed at an international level. This will enable better land-use planning, and better support for ecosystem conservation and restoration actions, which help to ensure the persistence of species and the services they provide.

    Source

    • Peter Pearman, Olivier Broennimann, [+ 48 authors] & Antoine Guisan, Mike Brufford. Monitoring species genetic diversity in Europe varies greatly and overlooks potential climate change impacts, Nature Ecology & Evolution, 2023.
  • They decode colonization methods through the communication of E. coli bacteria

    They decode colonization methods through the communication of E. coli bacteria

    Researchers have reproduced an intestine-like structure on a silicone chip. Here, a real mouse intestine, image credit: HistoPathology Core Facility, Institut Pasteur.
    Pietro de Anna, Institute of Earth Sciences

    Naturally present in our digestive tract, E. coli bacteria have very specific ways of communicating and colonizing complex environments. Scientists at UNIL have reproduced the complex structure of an intestine on a microchip, and unraveled these mechanisms for the first time. The study, published in Nature communications, represents a step towards a better understanding of host-microbe interactions.

    On average, a human intestine contains around 2 kilos of bacteria, or almost 10,000 billion individuals, belonging to 1,000 different species. Among them are the Escherichia coli bacteria, which are usually harmless and beneficial, but some minority strains are pathogenic. However, we don’t really understand the mechanisms that govern their behavior. How do they communicate with each other?  How do they colonize complex environments such as the human digestive tract?

    At UNIL, a team from the Faculty of Geosciences and Environment (FGSE), in collaboration with a team from the Faculty of Biology and Medicine (FBM), has unraveled the processes by which these bacteria colonize a sinuous environment. Two mechanisms were studied: their movement in response to chemical stimuli (chemotaxis), and their ability to estimate the number of similar bacteria in the vicinity (quorum sensing), and to react if there are too many. The research was published in Nature Communication. It opens the door to a better understanding of the relationship between microbes and their hosts, and the consequences for the latter’s health.

    An intestine on a chip

    To carry out their research, the scientists reproduced the structure of an intestine on a microfluidic chip, into which they injected nutrients (glucose) and E.coli bacteria. Bacteria spread in this confined environment, then accumulate in the cavities to take part in a small feast. They consume oxygen and absorb available glucose, releasing substances produced by their metabolic activity (such as AI-2). “This signal acts as a chemical stimulus, attracting other bacteria swimming nearby. As a result, the cavity fills up more and more, until it becomes crowded,” explains Pietro De Anna, professor at the FGSE and co-author of the study.

    A second phenomenon then occurs. When all the nutrients have been consumed, the bacteria activate a kind of sensor, enabling them to estimate the density of the crowd around them. “By estimating the quantity of signals, the bacteria suddenly notice that the place, which is a dead end, is full to bursting: their survival is at stake”, explains the professor. The bacteria then produce biomass faster than usual. They multiply as much as possible, to grow enough to get out of the cavity. 

    “Understanding how bacteria colonize complex, heterogeneous environments such as the gut is essential for understanding natural phenomena, and those that lead to their functioning or to pathology,” comments Pietro De Anna. “Furthermore, as AI-2 is a mode of interspecies communication, our research could provide valuable insights for other bacterial species.”

    Source
  • A simulation to visualize the evolution of Alpine ice cover over the last 120,000 years

    A simulation to visualize the evolution of Alpine ice cover over the last 120,000 years

    Guillaume Jouvet, Institute of Earth Surface Dynamics

    Scientists from the Universities of Lausanne (UNIL), Zurich (UZH) and Bern (UNIBE) have developed an unprecedented simulation which, in just 80 seconds, shows the evolution of glaciers in the Alps over the last 120,000 years.

    This complex computer model is the fruit of several years of research and intensive collaboration between climatologists, glaciologists, and geologists.

    The last glacial period began around 115,000 years ago, and was punctuated by cold and warmer cycles, resulting in the advance and retreat of glaciers that shaped the landscape of the European Alps and their surroundings, carving out valleys. A new computer model makes it possible to reconstruct this evolution with unprecedented precision. It provides a direct visualization of the phenomena, making them accessible to a wide audience. The fruit of an extensive collaboration by glaciologists, climatologists and geologists from the universities of Lausanne, Bern and Zürich, the research was published in the Journal of Glaciology.

    Climatology and glaciology meet

    The new numerical model is unique in that, for the first time, it incorporates complex modelling of past climate, carried out by climatologists at the University of Bern.

    Glaciologists then used these climatological simulations to inform an ice-flow model, modelling ice accumulation, dynamics and melting, resulting in the most accurate simulation to date. Its unprecedented complexity makes it possible to understand the past distribution of snowfall in Alpine valleys, as well as the evolution of glaciers. “There are geomorphological clues in the field, such as moraines and erratic boulders, which bear witness to the past imprint of glaciers on the lowlands,” explained Guillaume Jouvet, a glaciologist at UNIL’s Faculty of Geosciences and Environment, and first author of the study. “We used these traces to validate our simulation, and everything matched,” he further enthused. “Because of the complexity of the modeling, it took us 6 years to correctly set up our climate and glaciological models, and finally get the right climate and glaciers that match what we observe in reality.”

    The limits of modeling

    However, the traces left in the field, which act as a gauge, do not allow the model to be verified beyond 24,000 years, the period when glaciers were at their maximum. “This glacial maximum destroyed all previous evidence. Our model is therefore difficult to verify beyond 24,000 years,” explains Guillaume Jouvet.

    Putting global warming into perspective

    The new simulation will enable us to better understand the past interaction between climate and glacier, and how our landscape was formed. As well as being of scientific interest, it provides a context for global warming. “The image of the different glacial cycles is quite telling”, comments Guillaume Jouvet, “24,000 years ago, we can see that cities such as Lausanne were covered by more than one kilometer of ice. It’s obvious that past cycles, caused by orbital variations of the Earth, are nothing like what’s happening now, where greenhouse gases play an active role in glacier melt”.

    What is most striking is the speed of current climate change (barely a few decades) compared with the infinitely long time span of the ice ages.

    Guillaume Jouvet

    Scientists will be working to further improve the resolution of their model. The current resolution is not sufficiently fine to reproduce the complex topography of high mountains, and this causes a probable overestimation of the ice cover. “We have just started a new project using artificial intelligence, which will be used to speed up our models and reach a necessary resolution of 200m,” explains Guillaume Jouvet.

    Reference
  • Using rock surface luminescence dating to understand the dynamics of a glacier: a new approach initiated this summer at the Mer de Glace

    Using rock surface luminescence dating to understand the dynamics of a glacier: a new approach initiated this summer at the Mer de Glace

    This summer, three young scientists including Léa Rodari (student of the master in Environmental Science) went to the Mer de Glace (Chamonix, France) to extract icebound rocks.

    Their aim is to measure the time during which these rocks have passed through the glacier, using rock surface luminescence dating. This fieldwork marks the first step in a novel approach to directly quantifying the movement of ice and the objects it contains.

    Glaciers are not inert objects. Their mass is constantly moving from top to bottom, under the effect of gravity. With melting due to global warming, we are currently finding all kinds of debris, material – even human remains – at the end of the glacier tongue. Most often these objects were buried well upstream and were transported down with their surrounding ice. But how long did it take for these particles to make their journey and remain buried in the ice? Currently the evaluation of glacial dynamics (= speed of movement of the glacier) is mainly based on theoretical data and numerical models. Prof. Georgina King and her team are seeking direct observations of the glacier’s movement. To do this, she intends to determine the duration of burial of rocks that have been buried within the glacier, until their re-appearance in the open air. This new approach to the study of glacial dynamics is based on applying the luminescence dating technique to minerals contained in rocks. 

    The idea for the project comes from the fact that, although we know a lot about glaciers, we don’t know how long it takes to transport fragments within them, and that is because there were no methods available that you could use to really measure that.

    Glacier movements can have consequences for the downstream water regime (e.g. flash floods) or for the stability of glacier margins, for example. It is therefore important to understand glacier dynamics in order to better anticipate these risks.

    The first stage of this research took place this summer at the Mer de Glace above Chamonix (France). Léa Rodari student of the Master in Environmental Sciences and Audrey Margirier (post-doctoral fellow at the Institute of Earth Surface Dynamics – IDYST) shared their field experiences in this landscape that is both magnificent and physically and technically demanding.

    The first challenge of this expedition was to find interesting sites in the middle of the immensity of the glacier tongue, covered with rocky debris. The young scientists walked for two days to spot potential samples. One of the main difficulties was to distinguish the recently fallen rock debris from the summits from those that had stayed within the ice. In order to circumvent this pitfall, they took the option of concentrating their research on steep slopes (bordering crevasses or the supraglacial river,) which are free of debris that had fallen from the summits (i.e. where it was certain that the debris were englacial). The second challenge was to access these samples trapped in the ice cliffs.

    Sometimes we spotted an interesting rock on an ice slope in front of us, but we didn’t see it at all once we got to the top of the cliff, the wall being too vertical. Several times we had to rappel “blind”.

    Audrey Margirier
    Here above: various fieldwork activities and glimpses of the rocks searched for by the scientists (all photos of this article are from Léa Rodari, Audrey Margirier and Faye Perchanok, a master’s student also present in this field excursion).

    The rocks extracted from their surrounding ice were directly packed in opaque black bags to protect them from daylight, which interferes with the luminescence analysis. These samples were then prepared in the laboratory: cores were cut from the surface of the rocks, then sliced into thin 1mm discs. These operations were carried out in red light so as not to disturb the luminescence signals of the minerals in the rock.

    Rock extracts packed in opaque bags to protect them from light. 
    Preparation of disc-shaped samples for luminescence analysis.
    Prof. Georgina King explains what luminescence in rocks is

    Luminescence is the emission of light by minerals contained in rocks. The reason for this light emission is that these minerals, over time, have been exposed to radiation emitted by surrounding minerals, causing electrons to shift and become trapped in defects within the mineral. Exposing these samples to light of a certain frequency or color in the laboratory (in this case, blue or infra-red light), causes these electrons to return to their original orbit. This movement is accompanied by the emission of light of a different color, which can be measured. The amount of light emitted corresponds to the time during which the samples remained buried in the glacier, and therefore to the time it took the glacier to transport these rocks into the ice.

    It now remains to perform the luminescence analyses. This work will determine the duration of burial of the rock (time during which it was plunged into darkness within the glacier). The team is excited to get the first results to compare them with the values used so far. Georgina King concludes :

    We hope that the values we obtain will agree with the values predicted from numerical models. Otherwise, we will have some interesting discussions with the glaciologists to identify where the differences lie.

    Georgina King
    View of the Mer de Glace glacier with the Mont-Blanc massif in the background

    Going into the field involves risks

    They are quite high in this particular case, and required appropriate measures that were effectively put in place to ensure smooth operation. The FGSE has drawn up a guideline and a process to enable scientists going into the field to prepare their outing and assess the risks involved (preliminary risk assesment). External resources for information on the nature of the terrain are also mentioned (e.g. WSL-natural hazards for excursions in Switzerland).

    In the case of this research involving work on a glacier, people going out on site must undergo an appropriate prior training especially if they have no or weak previous practical experience on this field and its constraints (snow cover, crevasses locating, wheather analysis and monitoring etc.) use of equipment (proper use of crampons, ropes etc.) In this particular case, lone working is outlawed: as a precaution, activity on the glacier must involve the simultaneous presence of at several people, as this team of three scientists. 

    So even though the images may reflect an idyllic landscape, and “fun” activities, this fieldwork, like all others, required a very meticulous preparation and prior training to ensure that risks are minimized in terrain conditions which, as the images show, are very demanding for participants. Risk is always present, even for experienced and well-equipped people, and must be a constant concern, both for others and for ourselves.

    Directive FGSE sur la sécurité du travail de terrain

  • Towards a more inclusive and ethical paleontology

    Towards a more inclusive and ethical paleontology

    Farid Saleh, Institute of Earth Sciences

    Dr Farid Saleh is a paleontologist specializing in the formation of fossil deposits. In August 2023, he begins his Ambizione project at ISTE on the preservation of Cambrian fossils dating back over 500 million years.

    As Diversity Officer at the Palaeontological Association, he is actively involved in initiatives to promote diversity. His international experience – in Lebanon, France, Morocco and China – has enabled him to reflect on changing practices in the field of paleontology. He tells us how he hopes to foster collaboration and inclusion in his own work.

    You’re in charge of diversity at the Palaeontological Association. How did you come to take on this role?

    In 2018, the Palaeontological Association carried out a study on diversity among its members1. The results revealed that several communities were under-represented, particularly people from ethnic minorities and disadvantaged backgrounds. As a result, the association decided to appoint a Diversity Officer to develop an equality and diversity strategy and action plan.  

    I got the job, which I’m holding for three years, until the end of 2023. My experience as a Lebanese researcher who has worked in France, China and now Switzerland gives me a good understanding of the visions of the Global South and historically privileged European countries.

    What were your first actions as diversity officer at the Palaeontological Association?

    For example, we raised the issue of the living conditions of some members, which were not taken into consideration. The association’s membership fees, although very low, represent a large sum for someone whose salary has been reduced by the economic crisis, as is the case in Lebanon, or for students from certain regions. We have therefore reduced the price for people from low-income countries. 

    We have also introduced a new system for awarding ” Undergrad Research Bursaries”, to avoid bias in evaluation and increase the diversity of applicants. The principle is that of a random lottery, but with priority given to under-represented communities. Let me explain: the committee checks that the candidate projects are feasible and that the costs are justified. If these criteria are met, the projects are entered into the draw. Candidates also have the option of entering their nationality, ethnicity, sexual orientation and so on. This data, if provided, remains confidential. But it is used in the drawing of lots to favour under-represented communities.

    The Paleontological Association has also been working on a Code of Conduct2, which applies to all its members in the course of their professional activities. This code aims to “create an inclusive and diverse environment within palaeontology and to protect members from harassment and discrimination”. Members are expected to “promote a culture of scientific and research integrity, respect, fairness, and inclusivity and avoid conflicts of interest.”

    Finally, an international mentorship system now enables juniors to be guided in their career path and job search by a more experienced person. The support of scientists from different institutes around the world will help reduce inequalities in access to quality supervision and expertise.

    As a scientific discipline, paleontology has inherited a colonial history that has long excluded local communities in certain countries from the building of their collections. What has changed in the way the profession has taken account of inclusion issues?

    The situation has improved considerably over the last ten years. In the past, paleontologists considered it normal to collect material in a distant country, bring it back and publish the data, without taking into account the people and the region of origin of the samples. 

    The desire to integrate local communities and the importance of documenting the origin of fossils in research have emerged. These are really radical changes, because when I started my thesis in 2017, nobody was talking about these ethical issues. I myself was not very aware of these topics.

    Some countries, such as Brazil and China, now have laws banning the export of fossils (some even date back to the 80s). In Morocco, where I work a lot, the political will to protect our heritage is increasingly present.Countries with large fossil collections, such as Switzerland, France and the UK, are also putting in place regulations and principles to clarify field interactions linked to acquiring and working with fossils. Some countries are still lagging behind on these issues, particularly when it comes to the restitution of geological heritage, but the situation is improving and awareness is international.

    Of course, the restitution of fossils is costly, and it takes time to set up the infrastructures needed for their proper preservation on site. Morocco, for example, is in the process of building new museums to accommodate the large number of Moroccan fossils, in addition to the existing ones. To increase local expertise too, scientists are starting to work with local communities, involving them in research and training students.

    Publishers also play a role in changing practices. Some require proof of the origin of fossils, asking for export permits, the name of the person who collected them, etc. This is also a guarantee for them, as scientific papers have sometimes been retracted, for example because the authors were unable to demonstrate the legal provenance of their fossils, or because the fossils were illegally registered outside their country of origin.

    As part of your work as Diversity Officer, have you also worked on issues of gender or LGBT+?

    The diversity study carried out at Palaeontological Association showed that the LGBT+ community was not under-represented among its members, which is very good news. So we haven’t carried out any projects in this area for the time being. Nevertheless, we strive to create a supportive and secure environment in all our meetings, events, and sponsored activities. Any form of discrimination or harassment against members of the LGBTQ+ community is strictly unacceptable and is completely prohibited per our Code of conduct3.

    On the other hand, women are still in the minority. The association is now encouraging better representation of female researchers. My personal experience has also made me think about these issues. When I wrote my first scientific article, there were four co-authors – all men, none women. And yet, in my laboratory in Lyon at the time, I could easily have knocked on the door of the office next door to seek the advice of several female paleontologists. However, I considered our work to be of sufficient quality.

    But once the article was published, I had the opportunity to present it at a seminar, and a female expert I knew well gave constructive and useful criticism that could have improved our work! I’ve now got into the habit of presenting my results at conferences before publishing them. This approach allows me to refine them further and take a step back. Although some people argue that we should be wary of the risk of spoliation by revealing unpublished results, I consider these risks to be minimal compared to the benefits I derive from the valuable advice I receive. 

    Interacting with a large number of people allows me to discover databases and offers me new and different perspectives. I want to avoid building walls around myself, and I’m convinced that a diversity of viewpoints enriches our understanding.

    During your own fieldwork, which partners do you work with? In which countries?

    During my thesis, I worked on the Moroccan site of Fezouata, well known for its exceptionally preserved and diverse fossil assemblages. In Morocco, it’s often local people who collect the fossils. We work closely with Mohamed Ben Moula, a professional fossil collector. It was he who discovered the Fezouata formation, arguably Morocco’s most important fossil site, in the late 90s. The Paleontological Association recognized the value of his work and expertise by awarding him the Mary Anning Prize4 in 2017. Ce prix récompense les amateur·rices en paléontologie, mais dont la contribution a eu un impact important dans le domaine. This award recognizes amateurs in paleontology, but whose contribution has had a significant impact on the field.

    I then worked for two years with China, for a postdoc. And I never touched a Chinese fossil! It was a special situation, because it was during the COVID pandemic and I was working remotely. But you should know that in China, it’s almost impossible to export fossils. This is due to very protective laws and a very strong local infrastructure and expertise. So I was able to carry out my project from my place of confinement.

    In addition to collaborating with international amateurs and paleontologists, it’s also important for me to train local people, so that they in turn can make the most of their geological heritage. When we were in the field last May in Morocco, for example, we helped a motivated student to collect data and put together a solid thesis project in Switzerland.

    What advice would you give young researchers to promote inclusiveness?

    A fundamental principle to which I attach great importance is that of fostering collaboration and making it visible. It’s a principle I’d like to pass on to young researchers. One way of putting it into practice is to include in the list of authors of an article all the people who made that article possible.

    For me, this principle is of the utmost importance. According to some scientists and journals, a person only deserves to be a co-author if he or she has contributed to the “scientific” aspect. But is writing a paragraph or changing the discussion more deserving than discovering fossils? In my opinion, a scientific article is the fruit of the accumulation of various skills: from the person who found the fossil, prepared it and allowed it to be exported, to the person who analysed it or wrote up the results.

    As you can see, my papers often comprise a long list of contributors! For example, the colleagues who helped us obtain export permits are included in my thesis publications. Without them, the thesis wouldn’t have happened, and I’m grateful for their help. And although it’s not yet widely accepted, I’m not the only paleontologist to include amateurs in scientific articles. This shows that, in the field, their role is increasingly seen as essential. I think their inclusion also reveals the importance of the human aspect in paleontological research, over and above the scientific aspect: don’t forget that samples have a history, that they come from somewhere. What’s more, there is sometimes a lack of local academic paleontologists with whom to collaborate. This is partly due to our colonial past. Thinking about broadening the scientific community and valuing each other’s work is essential to advancing expertise in middle- and low-income countries.

    Farid Saleh, Institute of Earth Sciences

    Dr Farid Saleh is a taphonomist: he studies the degradation (physical, chemical, biological) of organisms in nature. On fossil deposits, this means trying to resolve these questions: to what extent do the fossils found reflect the original ecosystems? To what extent are they biased by preservation? If animals A and B are found in a fossil site, does that really mean they were the only ones present? Or did other animals live at that time, but their traces have not come down to us? 

    He is particularly interested in the first complex ecosystems – dating back over 520 million years. After studying in Lebanon and writing his thesis in Lyon, Farid Saleh now works at ISTE. To carry out his project, he has set up numerous international collaborations, with France, Morocco, China, Australia, Canada and the United States.

    Notes

    1. The results and recommendations of the diversity study are on the Palaeontological Association’s website ↩︎
    2. Find the Code of Conduct on the Palaeontological Association’s website ↩︎
    3. The Palaeontological Association’s Code of Conduct expresses its commitment to creating a diverse and inclusive environment. « The Palaeontological Association will not discriminate on the basis of race, colour, ethnic origins, immigration status, religion, age, marital status, parental status, sex, sexual orientation, gender identity or expression, socioeconomic background, educational background, or disability. » ↩︎
    4. Mary Anning (1799-1847), after whom the Palaeontological Association’s amateur prize is named, was a pioneering, self-taught paleontologist and fossil collector. Anning’s discoveries – such as early ichthyosaurs, plesiosaurs and pterosaurs – helped change our view of Earth history. To this day, her discoveries form an important part of the UK’s major collections. ↩︎
  • Fossil stories: testimony to a field in transition

    Fossil stories: testimony to a field in transition

    This series of conversations brings you the thoughts of our research community on field practice and how it is evolving. See also :

    Allison Daley, Institute of Earth Sciences

    As a paleontologist, prof. Allison Daley is passionate about the major events in the history of life and the early evolution of animal species. Her approach is to focus on specimens of exceptional preservation quality, enabling her to unravel the mysteries of animals long since extinct.

    Working in the laboratory at ISTE, but also on fossil sites in Morocco, she tells us about the changes taking place in her field and her actions to promote more inclusive teamwork.

    What’s field work like in your field?

    In my field of paleontology, there are two main types of fieldwork. 

    The first is exploration, with the aim of finding new fossil localities. This can be a challenging quest, even if you have good geological maps and try to target outcrops where you are likely to find new fossils. Access is also sometimes complicated, and a helicopter may be required.

    The second involves collecting samples from sites that are known to be rich and interesting. We spend weeks or months sampling specimens, and documenting their stratigraphic and sedimentological context.

    Where is your main fieldwork based?

    My work is based mainly in Morocco. I work a lot on the Early Ordovician Fezouata site, which contains fossils in an exceptional state of preservation. We can find animal soft parts, sometimes even their internal organs. And this site dates back to a period that fascinates me: just after the Cambrian explosion, but before a second great evolutionary radiation that followed during the Ordovician. Analysis of these fossils opens up fascinating perspectives on the early history of the Earth and the origins of biodiversity.

    What local partners do you work with? 

    My team and I go there on average once a year. But most samples are collected by a local professional collector, Ou Said Ben Moula, and his family, with whom we work a lot. He’s the one who found this exceptional outcrop and introduced it to paleontologists. He has no training in geology, but he knows the terrain like the back of his hand and has acquired incredible knowledge. 

    Mr Ben Moula attaches great importance to scientific research and knows how to recognize rare fossils of great value to paleontology. He therefore offers these specimens to museums and research institutes in the field (in Lausanne, Harvard, the Czech Republic…). He also runs a fossil shop, where he sells more standard fossils with less scientific value from all over Morocco.

    In certain regions of Morocco, the economy is based on the sale of fossils. Entire villages are dedicated to the research and preparation of specimens – such as the trilobites sold in “fossil fairs” – and to the sale of rocks containing shelly fossils, often used in construction as decorative building stone.

    In Morocco, ISTE researcher Dr. Pierre Gueriau (middle) and former ISTE PhD students Dr. Lorenzo Lustri (left) and Dr. Francesc Pérez Peris (right) examine Fezouata Shale fossils together with Moroccan fossil collector Lahcen Ben Moula (at back) (Photo credit: A. Daley).

    What happens to fossils from Morocco?  

    Today, the sale of fossils is a highly controversial business. The practice is sometimes perceived as “plundering” a region’s natural heritage. For my part, I understand the aspiration to preserve fossils locally within a Moroccan institution, and I hope that in time this will be possible thanks to the development of infrastructure in Morocco. However, as things stand at present, exporting is still the best way of studying these specimens and preserving them for the long term. 

    Paleontology is undergoing major changes. There is a growing awareness of a colonialist past. It’s true that Western countries have collected and appropriated many specimens, often without any compensation for the regions from which they came. Fortunately, attitudes and mentalities are changing, and there is hope that the situation will improve.

    Interesting initiatives are beginning to emerge. For example, each sample of the Fezouata collection currently housed at the University Claude Bernard Lyon 1 was imported from Morocco and assigned a specimen number belonging to the Marrakech Collections of the Cadi Ayyad University of Morocco, with a view to eventually return them to a future museum in Marrakech. For the moment, Lyon is simply housing these specimens, pending the establishment of a local infrastructure when the samples are returned.

    This initiative has inspired me personally, and I’m currently building collaborations with professors and museums in Rabat and Agadir. I hope that when the right equipment is available locally, we’ll be able to transfer the collections to these Moroccan institutions. In this way, we will contribute to the preservation of the country’s paleontological heritage and promote scientific research at a local level.

    “I think practices are evolving in the right direction, and I’d like to be part of the change.”

    Allison Daley

    What local collaborations exist with researchers?

    The scientific expertise and interest of local people in paleontology has increased. Khadija El Hariri is an active researcher and champion of the Fezouata locality, with whom we have co-authored several articles on the analysis of the preservation of soft parts from the Fezouata site. Vice-President of the International Paleontological Association and a researcher at Cadi-Ayyad University, Khadija El Hariri is extremely committed to the preservation of fossil sites. Together with Khadija and other researchers from Morocco, France, Belgium, Spain and Switzerland, we worked towards having the Fezouata locality designated as one of the First 100 IUGS Geological Heritage Sites.  Led by a collection of Moroccan universities and local organizations, there is also an initiative to create a UNESCO geopark in the Draa Valley region, so that the paleontological and archeological sites can be recognized and protected as a landscape of international importance, and contribute to education and sustainable development.

    Requests for geoparks always come from the country concerned, because if the project goes ahead, it will bring a huge amount of change. For example, the direct sale of fossils will be prohibited, even though many families make a living from this trade. In return, however, the project will enhance the region’s natural heritage and promote tourism. This could create a number of wonderful opportunities, such as the creation of a local museum in Zagora, or awareness-raising activities in schools. It could also strengthen people’s connection to their region.

    Moroccan fossil collector Mohammed Ou Said Ben Moula stands near the Fezouata Shale locality, with the sign announcing it as one of the First 100 IUGS Geological Heritage Sites (Credit photo : A. Daley)

    What do you see as your role as a researcher in a Swiss institution?

    I’ve been invited to sit on the scientific committee for this UNESCO application. I comment on the documents, explaining the scientific importance of the site. But I’m not involved in the political decision, which is up to the region.

    My role as a foreign researcher is also liked to training early career researchers, for example in the scientific methodologies of phylogeny and taxonomy. This is not always easy. Some Moroccan students, although brilliant and motivated, do not qualify for a PhD in Switzerland, or not directly, if they come from a university that’s too technical, for example, or because we can’t get funding. Our university certainly needs to think about how it can welcome and train promising foreign candidates. 

    For my part, I support early career researchers from Morocco in their applications to federal grants, and I hope that soon I will be able to welcome doctoral students and postdocs from Morocco here in Lausanne.

    Do you need special authorization to collect and bring back samples?

    Yes, we have to announce our arrival locally and regionally. This is important for safety and transparency. During our last exploration, it was professors from Agadir who helped us with these formalities and notified the village council.

    The export of collected samples is also regulated by permits. It’s a fairly cumbersome, time-consuming procedure. But it ensures the traceability of the fossils. The Fezouata fossil collection we purchased for UNIL was exported after permits were obtained from the Ministry of Energy, Mines and the Environment of the federal government of Morocco.

    Any advice for young researchers? What do I need to do before going out in the field?

    It’s not always easy to find out what you need to do before going out into the field. Who should I contact? Who provides authorizations? Good information is essential. For this, of course, a local contact is ideal. He or she will be in a better position to know the procedures, which are not always available on the Internet.

    What do you pay attention to when preparing the site? What’s changed today in the way excavations are organized?

    When I started conducting fieldwork as a young researcher, the question of inclusion didn’t arise at all. I sometimes reported situations in which I felt uncomfortable, or even dangerous. I was then confronted with insulting reactions aimed at ridiculing me.

    These are now discussions that I consider essential and that I lead within my group. I don’t want people to find themselves in situations like mine. We attach great importance to mutual respect, so that concerns and difficulties are expressed and taken into account. We have these exchanges before going out into the field, but also in our day-to-day work. We therefore go beyond the FGSE’s recommendations, which include a pre-departure risk assessment [Directive sur la sécurité et les mesures de protection pour le travail de terrain]!

    It’s encouraging to see that these ideas are gaining in visibility, not only at palaeontology conferences, but also in scientific journals in the field. This testifies to a positive evolution in the scientific community. Discussions also address issues specific to women, such as pregnancy, to ensure participation in fieldwork without discrimination.

    Allison Daley in Morocco examining specimens from the Fezouata Shale (Photo credit : P. Gueriau).

    What are your plans for the future?

    An ambitious project that combines paleontological studies with tourism studies… There are some exciting collaborations in the pipeline, notably with a partner involved in the Geopark.

    More information

  • From the farm to our plates: what are the margins in the supply chain?

    From the farm to our plates: what are the margins in the supply chain?

    How is the price we pay for our food distributed? Scientists at UNIL have launched a new research project aimed at shedding light on the margins achieved from agricultural production to household consumption, for a whole range of agri-food products. The project is funded by the canton of Vaud, and will put fruit and vegetables under scrutiny, as well as Vaud’s production of milk and cheese, meat, bread and wine.

    Transparency of costs and margins between production and retail is a sensitive issue, and one that often crops up in the Swiss media. But answering the question of margins is a complex and painstaking task, requiring trusting discussions with the entire chain: from farm to processing to distribution. This is the ambition and daily work of Floriane Gilliand and Armelle Rochat at the Faculty of Geosciences and Environment.

    Fair food prices are increasingly important to consumers. For their part, players in the agricultural sector are also calling for fairer negotiations and a better distribution of prices throughout the value chain. This is the background of this ambitious research project Transparence économique de filières agricoles vaudoises. Supervised by Dominique Barjolle (IGD), this project focuses on the canton of Vaud, and is financed by the Direction générale de l’agriculture, de la viticulture et des affaires vétérinaires (DGAV).

    By promoting transparency and sparking discussion between the various players, this project aims to lay the foundations for a fairer distribution of prices, strengthen trust between stakeholders and respond to growing expectations for economic justice in the agri-food sector.

    Floriane Gilliand and Armelle Rochat, the agronomists hired for this project, have the crucial task of convincing as many stakeholders as possible to participate and embrace transparency. The aim is to build a relationship of trust, in order to overcome the reluctance associated with the in-depth analysis of accounting data. Although this may seem a delicate task at first glance, it appears that many of their contacts are already aware of the benefits that increased transparency can bring.

    Floriane Gilliand is passionate about this economic issue, and devoted her Master’s thesis to it. “When you buy a cheese, you have no idea where the pennies you pay are going”. Armelle Rochat, who has also worked as a market gardener, is well aware of the difficulty of deciphering the costs of certain processed products. A basic product like bread, for example, passes through a variety of hands: wheat sown and harvested is ground into flour, then processed in the bakery. But this complexity and the passionate interaction with all the trades in the chain are a source of motivation for the two agronomists in charge of this fieldwork. They are also convinced that transparency will be a marketing advantage for stakeholders who play the game. “It will help bring credibility to the price we pay for food.”

    Data Analysis

    Once the data has been collected, it will be processed in complete confidentiality using software developed by UNIL doctoral student Inès Burrus at start-up Equal Profit. Specializing in the analysis of the fair benefits of exotic products, this tool will be adapted for application to products from the canton of Vaud.

    The results of field surveys, combined with anonymized databases, will be analysed according to the Transparent Profit and Equal Profit methodology. On the basis of these concrete results, workshops bringing together the parties concerned will encourage constructive dialogue between each of them.

  • Studying the impact of glacier retreat on biodiversity

    Studying the impact of glacier retreat on biodiversity

    Gianalberto Losapio, Institute of Earth Surface Dynamics (IDYST)




    Glaciers are the guardians of an entire ecosystem, and their disappearance caused by global warming will lead to a dramatic decline in biodiversity.

    In the field, the members of the Biodiversity Change Group are studying and documenting the impact of glacier retreat on biodiversity and ecosystem. Meet the group.


    “It may seem counter-intuitive, but glaciers and their surroundings provide very favourable conditions for biodiversity,” explains Gianalberto Losapio, PI at the Institute of Earth Surface Dynamics from the Faculty of Geosciences and the Environment (FGSE). “With the disappearance of glaciers, we are losing plant species, some of which may have strong medicinal potential, but also the fauna such as pollinators and predators associated with them”.

    With his Biodiversity Change research group, Gianalberto Losapio is spending part of the summer in the field at Ferpècle in Valais, documenting and studying the impact of glacier retreat on biodiversity and ecosystem functions. For several weeks, Bachelor and Master students, doctoral candidates and scientists from various countries are carrying out insect and plant surveys, analyzing soil and gas emissions, and parametrizing models to predict the distribution of species and conserve biodiversity.

    “Overall, we know that melting glaciers initially lead to an increase in biodiversity, with the arrival of pioneer plants and the colonization of insects. But over time, only few competitive species gain the upper hand such as larches and rhododendrons which ultimately dominate the scene”, explains Losapio. “This mechanism is already clearly visible to the nake eye. One of the missions of our group is to study ways of preserving this biodiversity”.


    This is the case of Luca Eiholzer, who is doing a master’s degree in environmental sciences at the FGSE. Equipped with a square meter and a GPS, he lists the presence/absence of targeted species – i.e. bioindicator species such as trees, moss, etc.– in around a hundred randomly distributed points in the proglacial margin. This data is then used to draw up an assessment of the current situation and projections for the distribution of species, with the help of machine-learning algorithms. “We hope that this information will be useful for the authorities, helping them, for example, to define areas to be protected. At the same time, being out in the field allows me to come face to face with the difficulties of collecting data. It’s very instructive.

    ”Eléa Pierre, a Master student specializing in geosciences, ecology and the environment, is interested in the influence that the presence of livestock can have on glacier margins. “I’m carrying out plant surveys around the Zinal, Arolla and Ferpècle glaciers,” she explains. “The idea is to compare changes in biodiversity depending on whether or not there is grazing around the glacier.
    There is a lot of uncertainty around the effects of livestock in these novel ecosystems.

    But according to our knowledge, large herbivores shape their environment, and not the other way round, through their diet, their dropping, trampling and their general behavior. These data could therefore be used to develop different conservation scenarios for sustainable management as these pastures are currently used by local population”.”


    Preparing for professional life

    Data collection generally lasts all day and is carried out by around fifteen people. The members of the group then meet up in a refuge, where they have their meals and spend the night. “Fieldwork is a great experience because, even though everyone is working on a specific project, we can talk to other researchers, help each other and work together,” says Eléa Pierre. Gianalberto Losapio adds: “We want the projects to be carried out independently, from start to finish. The idea is to prepare students for professional life.”

    Art meets science

    The work and research carried out at Ferpècle also include an artistic component. Gianalberto Losapio is collaborating with visual artist and artistic researcher Maëlle Cornut, who is following the group in the field. Funded by Pro Helvetia and the Swiss Polar Institute, the art-science project, which will run for almost two years, focuses on the consequences of the extinction of glaciers on ecosystems, but also addresses broader concepts such as ecofeminism, ecology decolonization and climate justice. It will include videos superimposing micro images of plants and insects and landscape images to show the interconnections between the various scales. “So far, we’ve done a lot of research and shared our practices and ideas. I’ve now started the production phase, installed several cameras traps, and the concrete part of the project is about to begin”, she explains.

    Gianalberto Losapio, Luca Luca Eiholzer and Maëlle Cornut
  • Jorat Natural Park : first steps towards long-term monitoring

    Jorat Natural Park : first steps towards long-term monitoring

    A new peri-urban park was born in the Jorat woods in 2021, becoming the second of its kind in Switzerland.

    Pascal Vittoz (IDYST) is involved in the initial monitoring of this forest, which is entering a new phase following the complete cessation of logging. How will this forest landscape, a favorite walking spot for Lausanne residents, evolve over the next 50 years? The first milestones have been set, and now we’ll have to let the forest give us the answers, at its own pace.

    Armed with a map and a compass, Pascal Vittoz ventured through the thicket in search of the plot he was to survey today. A traverse through the brush reveals an area dominated by spruces. These conifers, planted in the 19th or early 20th century because of their rapid growth, are still predominant today. Without human intervention for economic reasons, this area would be covered with fir and beech today.

    How will the forest, its wildlife and its inhabitants evolve in the future? That’s what this study is all about. Pascal Vittoz is in charge of monitoring the flora, in particular the undergrowth, in order to study the consequences of the creation of the forest reserve on floristic diversity. These surveys will be carried out every 10 years, in collaboration with a commissioned botanist, Loïc Liberati, former student at FGSE (Faculty of Geosciences and Environment) and Patrice Descombes, former student at FBM (Faculty of Biology and Medicine), and current curator at the Lausanne Botanical Garden. They share the 132 monitoring points randomly distributed throughout the forest plots, according to a plan drawn up by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), with the aim of observing the future of the forest.

    The Jorat Natural Park is divided into parcels to facilitate and organize flora monitoring. In the north, the park’s “core zone” is no longer managed by foresters. (Photo: A. Dreiss).

    The new Jorat Natural Park aims to encourage the presence of dead wood. With it, certain birds that burrow into old trunks, beetles whose larvae feed on wood and fungi that decompose dead trees will flourish. One part of the forest – the central zone of the park – will remain untouched for the next 50 years: no cutting, no logging, no off-trail passage. It will simply be left to its natural evolution, with the exception of a few necessary cuts to ensure trail safety. In the transition zone further south, towards the Chalet à Gobet, logging will continue as before, but certain measures will be put in place to promote biodiversity and welcome the public.

    In each plot, the botanists examine two concentric surfaces around the point selected at random by WSL. They describe the structure of the forest and list the flora in the herbaceous, shrub (less than 3 meters high) and arborescent (more than 3 meters high) strata. This gives us an idea of regeneration: if a tree type is present in all strata, it has a good chance of remaining in the future forest.

    The botanists draw up a complete inventory of the flora in two concentric zones, starting from a central point marked on the photo by a blue stake. The first disc, measuring 10 m², corresponds to the standard used for biodiversity monitoring in Switzerland. The second, measuring 200 m², gives a more complete picture of the undergrowth flora, providing a better description of forest structure, such as tree size and proportion of dead wood.

    Pascal Vittoz measures the tree stratum using a convex grid mirror.

    A beetle trap suspended in the middle of the plot bears witness to the various monitoring activities carried out by other groups of scientists. To explore the future of the forest, regular surveys are carried out to study its uses (pedestrians, bicycles, horses) and fauna (beetles, batrachians, deer…).

    After logging ceases, we can expect the trees to age, leading to a denser, darker forest, with less light reaching the ground and therefore fewer plant species in the undergrowth. However, the vagaries of storms and climate change make predictions difficult. Spruces, for example, could suffer from the heat and be partly decimated by attacks from the bark beetle. In a conventional forest, foresters cut down affected trees to contain their proliferation. But what will happen when there are no longer any health checks on the trees? Will the bark beetle spread further? Will their presence favor species other than spruce?

    « This reserve is set up for 50 years, which is more than half a human lifetime, or about ten times a standard research project. » Pascal Vittoz

    So we’ll have to wait to see the benefits of this park materialize. Typical research projects are planned to last 3 to 4 years. In this case, that’s not long enough to study forest flora, which evolves very slowly. This study, which spans the entire lifespan of a tree, will not deliver its results for several decades.

    What do botanists find in the Jorat woods?
    Wood horsetail
    (photo : P. Vittoz)

    The forest is dominated by spruce and beech, with undergrowth often lacking in plant diversity. However, some wetter areas, such as ash groves, offer surprises and less common species. Horsetail, a common species in the Alps but much more widespread on the Plateau. Horsetails are among the oldest plant species, having appeared nearly 400 million years ago. Some species were important trees in the Carboniferous period, while today’s largest representatives grow to around 1 m.

    More informations

  • Uncovering the secrets underground: how micro-scale processes in soils have global impact

    Uncovering the secrets underground: how micro-scale processes in soils have global impact

    Marco Keiluweit is a specialist expert in soil biogeochemistry who joined the Institute of Earth Surface Dynamics in July 2022. He is particularly interested in the role of soils in climate change and the global carbon cycle. His current research focuses on fundamental processes that regulate soil organic matter dynamics, which determine soil carbon sequestration and soil health. Here, he and his first assistant Emily Lacroix talk about the team’s ambitious agenda. It encompasses both the grand scale of natural environments and the microscopic intricacies at play within them. By connecting these dots, their work will pave the way for advancing our understanding of the complex interplay between soils, climate change, and sustainable agriculture.

    Exploring a complex universe

    Marco Keiluweit: Conducting research in soils is a challenge: they are highly complex and dynamic systems. Plants, microbes, minerals, and organic matter interact and are in a constant state of flux. My aim is to gain a better understanding of the dynamics governing soils. Isolating and describing the physical, biological, and chemical processes involved is a long-term quest.

    Soils are much more than just a pile of dirt; they are teeming with life, with plants, microbes, and minerals interacting in a complex choreography. The physical, biological and chemical processes animating this dance are so intimately interwoven that it becomes difficult to isolate and study them individually.

    The carbon cycle in soils is the key focus of  our research. We are seeking to better understand the mechanisms that store carbon in soil or release carbon from soil. This capacity determines whether soils will accelerate or help mitigate climate change in the future. In fact, soils store around three times more carbon than the atmosphere and biosphere combined. Understanding how soil carbon cycling is affected by climate change is therefore of the utmost importance. 

    Beyond the environmental aspect, the study of soils is also of crucial economic interest. Agricultural fertility and productivity are closely linked to soil carbon cycling. Understanding how this precious element influences the quality of arable land paves the way for more sustainable and efficient farming practices.

    From macro to microscope approaches

    Marco Keiluweit: Delving into the intricate mechanisms of the carbon cycle and deciphering the impact of environmental perturbations such as climate change on these processes requires a multi-level approach. At a macroscopic level, our ultimate goal should be to tailor land management strategies to the unique characteristics of each soil type, achieving the delicate balance of optimizing plant productivity while curbing CO2 emissions.

    By unravelling the intricate relationship between soil management and carbon storage in the soil, scientists hope to unlock the key to maximizing yield while minimizing the carbon footprint of agriculture.

    We are also studying natural ecosystems, for example in the Alps. In alpine soils, 90% of carbon is stored in soils. We are interested in assessing how this vast soil carbon pool responds to changing snow cover. We are currently monitoring how the soil carbon cycle in these systems responds to changing snow melt dynamics in alpine regions.

    Soil microelectrodes that continuously measure the chemical parameters influencing carbon cycling in soils, for example nutrient levels, oxygen content, moisture, etc. Placing several of these sensors in a field allows scientists to assess the spatial, seasonal and temporal variations in soil carbon dynamics in the field.

    Marco Keiluweit: On a smaller scale, our research focuses on the rhizosphere. This is the soil zone where plant roots meet the soil. Roots release carbon compounds into the soil (sugars, organic acids), which microbes absorb, fix in the form of organic carbon, then metabolize and release in the form of CO2. A detailed understanding of these plant-microbe-soil interactions and their variations will enable us to determine under which conditions the soil will tend to store or release carbon.

    A prototype for studying the root system under controlled conditions. The plant is grown in vitro in a medium contained between a glass plate and a molded polymer. It is also possible to test different factors such as nutrient and humidity levels or the presence of micro-organisms on gas transport and consumption.

    Emily Lacroix: My particular interest is in anoxic microsites: pockets in which there is no oxygen. This is particularly true in the vicinity of roots. These pockets have an influence on the global carbon cycle, as microorganisms there convert organic carbon into CO2 less rapidly. My main questions are: where and how do such microsites form in the rhizosphere? Is their frequency linked to soil moisture or texture? Can we measure their influence on the soil’s capacity to fix or release CO2?

    To observe the formation of anoxic pockets (microsites) in situ, Emily Lacroix inserted soil into a reactor. The same soil is mixed with quartz crystals (not very reactive) of different sizes to simulate variations in texture without changing the nature of the soil (see different colours of samples in the image on the left).
    A “false root” – corresponding to a microdialysis probe (photo right) – releases carbon into the soil, just like a real plant root. Its advantage is that it allows precise control of the amount and type of carbon released into the soil.
    The soil’s moisture content can also be modified to identify its potential influence on the formation of anoxic pockets.

    At the end of the experiment, Emily Lacroix measures the oxygen level and its distribution in the sample: a chemical foil reacts to the presence of indicator oxygen (pink square on the left image). This paper is then exposed to a camera equipped with a UV lamp (central image). On the screen, oxygen-rich areas appear orange-red and anoxic areas yellow-green (right image). In this way, it is possible to quickly identify the distribution and number of anoxic zones in the vicinity of a root.

    Marco Keiluweit: Finally, on a microscopic scale, we analyse soil samples using a cutting-edge, high-resolution infrared microscope. Its high level of resolution enables us to describe the interactions of organic matter, minerals or microbes in our samples.

    Characterizing the associations of microbes and minerals in soil samples is one of the feats made possible by the infrared microscope. The resolution of this microscope makes it possible to distinguish different types of soil organic matter (dead or alive) and minerals in soil samples.
    This is the only infrared microscopes of this kind in Switzerland and has a rapidly growing user base FGSE as well as at other  institutions in the fields of geosciences, microbiology and engineering.

    The Road Ahead: Linking fine scale mechanisms to macroscopic observations

    Marco Keiluweit: Our aim is to better predict how soils respond to climate change going forward. And we can only improve our predictions of this response by linking macroscopic observations of change to microscopic mechanisms. We have seen a rapid advance in our understanding of soil carbon dynamics in recent years, which makes me hopeful that we will be better equipped to address the mounting pressures on our soils arising from climate change and intensification of land use in the future

    Emily Lacroix: I hope that my first experiments under controlled conditions will be conclusive, so that I can measure the formation of anoxic pockets (microsites) close to real roots under real conditions. With successful results, I aim to conduct measurements that will enhance our understanding of how these crucial processes influence soil carbon dynamics. 

    Pour en savoir plus

  • Investigation in Madagascar – ethnographic fieldwork in a rural landscape

    Investigation in Madagascar – ethnographic fieldwork in a rural landscape

    This series of conversations brings you the thoughts of our research community on field practice and how it is evolving. See also :

    Christian Kull, Institute of Geography and Durability

    Christian Kull is interested in environmental management in rural landscapes. He has worked in Tanzania, Kenya, India, Vietnam… But it was in Madagascar that he completed his master’s and doctorate. He fell in love with the landscapes of the country’s high plateaus, a mix of forests, terraces and small farms. He tells us how he conducts his ethnographic fieldwork.

    Christian Kull is a geographer. His work aims to shed light on the global environmental issues of our time. Environmental management is a central issue affecting human well-being, economic prosperity and sustainability. Rooted in the scientific disciplines of Political Ecology, Development Studies and Environmental Humanities, Christian Kull explores the historical, ideological and political-economic genesis of environmental problems and the conflicts that accompany them. To understand the dynamics of governance and foreign intervention, he has worked in deprived regions of the world.

    Christian Kull was president of the CER-GSE when it was launched in 2020, and helped to set it up. In this interview, he talks about his long-term work on wildfires and invasive plants.

    What partners do you work with?

    I have a particular interest in local stakeholders. I try to understand how people manage the environment around them, why they plant this or that, cut down trees, burn vegetation… And how these practices interact with national and international policy.

    So I work mainly with peasants, but also with people in the rural world – those with administrative positions, the pastor (churches play an important role here), the local school teacher – and on a more global level, with government and NGO officials, people in bilateral aid and at the university.

    Malagasy farmers explaining land use (Photo: Ch. Kull, 2006).

    How did you first come into contact with the people you want to interview?

    Now, I almost always undertake a project in partnership with the local university, in particular with their school of agronomy, forestry and environment, but also with the geography department. For my Master’s, it was totally different: I bought a plane ticket without knowing whether the professor to whom I had sent a handwritten letter had received it. As soon as I arrived, I knocked on the doors of people at the University of Antananarivo whom I knew only through their articles.

    They introduced me to a student, Arsène Rabarison, whom I then hired as a field assistant, as I didn’t speak Malagasy yet. Arsène also helped me in my learning: discovering rural life, knowing how to behave, learning about networks and how to find accommodation, etc.

    The peasants are welcoming, and in the hamlets you’ll always find someone to offer food and a place to sleep. The next day, they sometimes send a child to show you the way for a few hours.

    “In 1994, I set off with the 1969 Atlas of Madagascar. Some of the plates caught my interest: very precise field maps, 1 km by 1 km, where land use was mapped. My idea for the Master’s degree was to go and see 25 years later what had changed, and to explain these changes by talking to the people on the spot. I arrived in a village I’d chosen without knowing anyone there. But I could show them this map. Some of the elders even remembered the ‘French professor’ who had made it!”

    Do you need permission to discuss your research questions?

    I deal mainly at the local level, with the local town hall. But I also have a letter from the university. For local officials, it’s already a passport if someone in the capital has validated the project.

    When I worked at Monash University in Melbourne, Australia, I had to follow a more bureaucratic ethical procedure, guided by the challenges of medical research, and aimed at avoiding past abuses towards Aborigines – who suffered from exploitative research. In Madagascar, I always managed to argue for oral consent adapted to local traditions (including formulas for thanking God…). I think the farmers appreciated this effort! For them, signing a piece of paper is rather worrying, and they don’t always read well, so oral consent is preferred.

    The ethical form advocated by my thesis university in the USA and by Australian universities was based on the premise that we alone are in a position of domination and power in relation to the locals in these exchanges. Although I have also observed that the figure of the researcher sometimes still commands too much “postcolonial” respect, I am critical of this perspective. I have chosen an oral consent procedure for pragmatic reasons, but also out of conviction. I consider that the people I interview also have a form of power, so I don’t need their signature to formalize our interaction. And I observe it too: if they don’t want to answer, they skirt around the questions with ease, they lie… I trust them! The key point before an interview is to say what I’m doing, that I’m not going to use their name and that they can choose not to answer.

    (Photo : Ch. Kull, 1998)

    How do you deal with sensitive issues that can get people into trouble?

    I’ve worked on fires, which are often illegal. But I never ask directly who started a fire. Instead, I’d say: “Did you see the day before yesterday, there was a fire up there. Why?”. And I’m never told, “I lit the fire for that reason”; but, for example, “I suspect that whoever lit it did so for that reason”.

    In my research, I move forward by piecing together observations, by triangulation, building up an argument little by little as if I were conducting an investigation. The Malagasy way of speaking is also rather indirect, so you have to know how to decode!

    How do you protect data on illegal practices, such as fire? Do you need to ensure source anonymity?

    The issues I’m working on with my partners and team are not highly sensitive, and again, the evidence is indirect since no one says “I started that fire” or “I cleared that forest illegally”.

    However, from the outset, the information gathered is separated from the real name of the source. And no file contains both elements, thus preventing cross-checking. If necessary, a correspondence file exists, but separate and password-protected (the name of the file shouldn’t be obvious about the nature of its contents either!).

    During my PhD, in my notebook, there were no real names. “Goatee” referred to someone with a small beard. I named a peasant “Ruedi”, who reminded me of my uncle of the same name…

    “The context of the interview is important: are we going to people’s homes? Is it relevant? Socially possible? Do we have their trust to do so? What do we have to give in return? Farm families often offer food. During my thesis, I decided to take a photo of the family – back in the days of 35mm film camera, when you had to go up to the city to develop the photos. It wasn’t a means of exchange, but a way of thanking them… That said, after 20 families, word got around, and when I arrived for an appointment, they’d put on their Sunday clothes. It made them really happy.” (Above: examples of family photographs to thank participants. Photo: Ch. Kull, 1998)

    What advice do you have for young researchers before they head out into the field?

    I brainstorm with them on interview guides, but the field is really a learning experience. I trust them. You have to dare to try things out, see what works and adjust if necessary.

    At Bachelor’s level, students are introduced to qualitative research and learn how to construct a survey. So they have a good grounding, and good manuals too. But it’s all theory … until you’re facing someone you want to interview!

    How do you get people to agree to talk about their practices? It’s a social process, where a smile and the way you present yourself are just as important as your knowledge of cultural codes (what’s acceptable, what’s not). Sometimes it’s explaining what you’re doing that’s decisive, sometimes it’s convincing the mayor beforehand. But fortunately, in Madagascar as elsewhere, people like to talk about their lives, as long as someone is interested.

    In the Master’s program, we also try to expose students to an “exotic” context. It has to be justified in terms of budget and climate impact, but these are essential learning moments.

    Are there any mistakes to be avoided when designing an interview?

    A subject close to my heart is that of invasive species. At the beginning, some students ask questions that already contain the answer: “What do you think of these invasive species?” If we ask the question like that, the foresters or farmers will try to please us, and say that these species “invade” them… If we ask them, “What do you think of eucalyptus, their strong and weak points?”, we’ll get other answers. Only then can we go further: “Have you heard that they are invasive? What does that mean to you?” It’s not the same conversation.

    “Here I am with farmer and shop-owner Augustin “Radatatoa”, in 2018, in Laimavo, Madagascar. He’s carrying photos taken in 1994 during my master’s work, which I mailed to him.” (Photo: Ch. Kull)

    How has your relationship with local people developed over time?

    For my PhD, I decided to spend four and a half months immersed in the culture and taking intensive Malagasy language courses. Every afternoon, I got on my bike and went to practice basic exchanges with farmers (“Do you grow rice?”). Then I lived in a village for 10 months. Staying in the field for so long allows you to learn a lot about the context in which specific issues are situated. For me, this is invaluable, and it’s the only time in a career when you have the freedom to do this. Little by little, you come to understand the networks, the stories of friendship, family, clan, religion, all those things that are so opaque at first. That’s what our students don’t always have the time to do now.

    The ethnographic approach takes time. It’s quite different from the more formalized research interactions that are now being taught more and more.

    “I work the old-fashioned way, notebook in hand. At the end of the day, I add notes, reconstruct, sort. I note down my observations, my conversations, but also all my encounters. Otherwise, two years later, I get everything mixed up, and it’s essential to remember people.”

    To go further

    Christian Kull, Institute of Geography and Durability

    Christian Kull is an expert in research on wildfires, a phenomenon that has a major impact on carbon dynamics, biodiversity and ecosystem services. As part of a SNIS project (Swiss Network for International Studies), he is currently exploring the most balanced fire management strategies to meet the needs of local communities and the challenges of climate change. With partners from Swansea University (UK), Antananarivo University (Madagascar), Eduardo Mondlane University (Mozambique), the South African National Parks and the UN Food and Agriculture Organization Madagascar, he is targeting biodiversity hotspots in Madagascar and southern Africa.

    He has also contributed to our understanding of invasive species and plants, deforestation and reforestation, protected areas and agricultural conversion.

    Discover Christian Kull’s profile, blog and scientific publications.

  • The University of Lausanne and the Natural History Museum of Geneva receive samples of the famous asteroid Ryugu for their scientific research

    The University of Lausanne and the Natural History Museum of Geneva receive samples of the famous asteroid Ryugu for their scientific research

    Johanna Marin Carbonne (FGSE) and Nicolas Greber (MHNG)

    Scientists from the University of Lausanne (UNIL) and the Museum of Natural History of Geneva (MHNG) have been selected by the Japanese Aerospace Exploration Agency (JAXA) to work on two samples of the asteroid Ryugu, one of the most primitive objects in the solar system.

    The specialists have one year to analyze the chemical composition of these samples, which arrived in Lausanne recently. Their study aims at a better understanding of the water and sulfur cycle in the early solar system.

    • Ryugu is a witness of the time when the solar system and the planets were formed.
    • The samples, taken directly from the surface of the asteroid, are in a unique state ofpreservation.
    • Ryugu is a mine of information and it could help to lift the veil on fundamental questions suchas the formation of the solar system and the origin of life on Earth.
    • The UNIL and the MHGN will study the evolution of sulfur and the nature of water on Ryugu.They will contribute to the question of the origin of water on our planet.

    In 2020, the Japanese space probe Hayabusa 2 brought back to Earth 5.4 grams of the asteroid Ryugu, located at nearly 300 million kilometers from Earth. This exceptional celestial object, rich in carbon and with a diameter of 900 meters, is one of the most primitive in the solar system.

    Echantillon Ryugu (photo credit: Jaxa)

    Many studies are underway around the world to analyze the composition of Ryugu and to trace its evolution. The first studies have already delivered groundbreaking results, and scientists are going from discovery to discovery. The last one revealed that on Ryugu, the necessary building blocks for life are available. The future research should allow to lift the veil on fundamental questions concerning the constitutive elements of the solar system – which also make up the earth – or the appearance of life.

    At the University of Lausanne (UNIL), specialists from the Faculty of Geosciences and Environment, in collaboration with the Natural History Museum of Geneva, will contribute to the study of two asteroid samples entrusted by the Japanese Aerospace Exploration Agency. The scientists will analyze small mineral grains, about 50 to 500 micrometers in size. For comparison, the thickness of a human hair is about 80 microns.

    The measurements will be performed with the SwissSIMS ion probe, a very powerful analysis instrument unique in Switzerland and installed at UNIL as part of the Advanced Center for Surface Analysis (CASA).

    Did asteroids bring water to Earth?

    “Originally, Ryugu was formed by condensation of dust and ice,” explains Johanna Marin Carbonne, co- director of the research, and professor at the Faculty of Geosciences and Environment of UNIL. “Then the ice melted, and fluids started to flow on the surface of the asteroid. With our team, we will study the composition of the rocky part of Ryugu, and how it was altered by the passage of the fluids.”

    Scientists will focus on the analysis of two minerals: sulfides and apatites, which are rich in volatile components (elements with a low boiling point) such as chlorine, sulfur or fluorine. These analyses should give valuable information on the initial composition of sulfur on Ryugu, and by extension, that of other elements in the solar system, as well as on the nature of the fluid that passed through Ryugu.

    “We will try to reconstruct the composition of the oldest water on Ryugu and to see if the chemical signature of this water is comparable to that found on our planet,” says Nicolas Greber, co-initiator of the project and researcher at the Museum of Natural History in Geneva. “One of the major underlying questions is whether or not the asteroids brought the water to Earth,” he says.

    Two Swiss projects selected

    In Switzerland, two projects have received Ryugu grains for this round of sample allocation. The joint project UNIL & MHNG, and the one of ETHZ, led by Professor Henner Busemann. “It is an invaluable chance to be able to study these samples”, rejoices Johanna Marin Carbonne from UNIL. “There are meteorites on Earth of the same family as Ryugu, but they have been altered by time and by the passage through Earth’s atmosphere during their fall. In this sense, the Ryugu samples are unique”.

  • Digital Twin Cities : the need to integrate more complexity in the analysis

    Digital Twin Cities : the need to integrate more complexity in the analysis

    Céline Rozenblat, Institute of Geography and Durability (IGD)

    Virtual representations of cities – or Digital Twin Cities – are in full expansion and are intended to facilitate the management and planning of urban systems in the short and medium term. But are they relevant?

    The European Union has mandated a group of experts in modeling, which includes Prof. Céline Rozenblat, in order to evaluate them. The result: the models suffer from a lack of complexity, and neglect in particular the socio-economic components of the urban fabric, as well as the approaches at different levels and scales necessary for long-term sustainable urban development planning.

    Created more than fifty years ago by NASA to test rockets, the “digital twins” have progressively developed in many fields. In the last few years, the development of Digital Twin Cities has grown in parallel with the research conducted on the subject (> 400 articles published in 3 years). 

    They are the virtual representation of the processes and systems that make up the city. They aim at facilitating its management and planning in the short and medium term. Their modeling relies on large amounts of data from human and physical systems, for which automated sensors are available to provide this data in near real time.

    In 2022, a commission of experts, including Céline Rozenblat, professor at IGD, has been mandated within the European Union to establish an ISO standard defining the criteria to be met for the establishment of local digital twins. An article published in Nature computational sciences “The role of complexity for digital twins of cities” (full-text access to a view-only version of your paper by using the following SharedIt link) reviews the existing models and addresses several criticisms: lack of transparency of the data and models used; focused on the infrastructures and buildings of the cities; analyses carried out at the same scale and stopping most of the time at the administrative limits of the central city. This “mechanical” approach shows significant shortcomings and neglects elements that are crucial to the development of a city, such as the economic fabric and social links. Also, interactions at micro-levels can influence elements at a larger scale.

    Thus, according to the experts, it is necessary to introduce in digital city models several levels of complexity and different types of data, in order to have the most faithful representation of real cities. It will thus be possible to meet the needs of the governance of these cities by giving them the means to act at several levels, as well as at different scales of space and time.