Hauptinhalt
Topinformationen
32nd Systems Science Colloquium
Winter semester 2025/26
The colloquium takes place on Wednesdays from 16:15 to max. 17:45, in room 66/E01 (Barbarastraße 12).
Program
17 October 2025
Dr Marianna Cerasuolo, School of Mathematical and Physical Sciences, University of Sussex (UK)
Mathematical Insights into Soil Carbon and Sustainable Agriculture
Climate change affects various aspects of agricultural production, including fluctuations in temperature and precipitation that impact nutrient cycling, soil moisture, pest occurrences, and plant diseases. In response, crop diversification and a range of management practices are being explored as methods to address these challenges. The amount of carbon in soil is often used as a proxy for soil health, and increasing the capture and storage of carbon dioxide has the potential to positively impact climate change mitigation. However, soil carbon dynamics are slow, and data-informed mathematical models are necessary to support research in agriculture, such as predicting the impact of innovative cropping strategies.
In this seminar, I will present results from the research undertaken within the Diverfarming project (www.diverfarming.eu), which aimed to promote sustainable agriculture in Europe through crop diversification and reduced-input farming. A central aim was to apply mathematical and statistical methods to evaluate the environmental and economic consequences of diversified cropping systems. Our analyses showed that while such systems may yield less in the short term, they often enhance resilience, improve soil function, and lead to comparable or improved profitability over time. Using the experiment-based mathematical model ECOSSE-M, developed within the project, we examined the effects of diversified cropping systems across six European countries, considering soil–water–atmosphere– plant interactions at both farm and landscape scales. In particular, I will focus on the Po Valley in Northern Italy, where mathematical, statistical, and machine learning approaches were employed to investigate the spatial dynamics of soil carbon in intensive agricultural systems. This allowed us to quantify the effects of different management practices and identify key drivers of carbon storage.
Our results provide science-based evidence on the role of crop diversification in improving soil health and mitigating climate change, and demonstrate how sustainable agricultural practices can enhance resilience, reduce environmental impacts, and support long- term ecosystem health.
22 October 2025
Dr. Christoph Schünemann, Leibniz-Institut für ökologische Raumentwicklung (IÖR) Dresden (Germany)
Integrating Social Complexity in Policy Advice to better understand Transformation Processes
Traditional policy modelling often relies on rational economic assumptions, overlooking real-world decision-making complexities influenced by psychological, social, and systemic factors. Existing psychological or socioeconomic decision-making and behavioural change theories provide insights into how cognitive biases, social identity, values and norms or bounded rationality affect behaviour. Despite their relevance, these theories are underrepresented in policy assessment and modelling, often due to their conceptual fragmentation and the lack of psychological expertise in the policy development process. To address this gap, the use of systemic behavioural change modelling is proposed, combining psychological decision theories with complexity science, i.e. system modelling approaches. A case study explores this approach by developing a systemic decision-making model for homeowners’ decisions to adopt energy retrofit of their houses. The model builds on the Rubicon Model and maps decision-making phases—pre-decisional to post-actional—while integrating societal influences like media and social norms in several feedback loops.
05 November 2025
Dr. Judith Klein, Fraunhofer-Institut für Molekularbiologie und Angewandte Oekologie IME (Germany)
From Molecules to Models: Computational Approaches for Ecological Risk Assessment
Assessing the environmental risks of chemicals requires an understanding of both exposure and effect processes. This presentation provides an overview of key modelling approaches used for environmental risk assessment—from exposure models such as FOCUS PELMO and GeoPELMO, which estimate chemical concentrations in groundwater, to effect models like the GUTS model that describe survival of organisms under dynamic exposure conditions. The integration of mechanistic modelling, bioinformatics, and geospatial data enables more realistic, science-based evaluations to support regulatory decision-making and sustainable environmental management.
12 November 22025
Prof. Dr. Andreas Beyer, Universität zu Köln (Germany)
Analysis of molecular high-throughput data to understand cellular systems
Cells are very complex systems that are composed of billions of highly diverse biomolecules. These biomolecules execute enormously complex cellular functions in a highly coordinated way. Clearly, understand how a cell works requires a systems approach. We have contributed computational methods that extract mechanistic biological insight from high-throughput profiling data of DNA, RNA and protein molecules (genomics, transcriptomics and proteomics data). I will present exemplary present methods that integrate such data using network-based approaches, machine learning, and relatively simple, yet powerful statistical approaches. Using these examples I will show how insight about the functioning of molecular systems and their malfunctioning during aging and disease can be inferred from large molecular datasets.
19 November 2025
Dr. Geeske Scholz, Bremen University (Germany)
Formalizing social science theory for computational models
Behaviour and behavioural change are crucial to many of our current challenges, such as climate change mitigation and adaptation. The importance of social dynamics and situated behaviour (which is triggered by and follows situational cues) is something I studied empirically and also addressed with agent-based models. Agent-based models reflect great potential to better understand the macro effects of behavioural dynamics. However, the representation of human behaviour in models is often oversimplified and not backed up by research, with significant consequences for model validity. Using the broad body of theories of human behaviour remains a significant challenge for modellers, and the learnings of formalization and modelling for social science research still need to be explored. In this talk, I discuss the potential of combining social science research with social simulation models, focusing on the formalization of theory. I will discuss current work on selecting, formalizing, and incorporating theory from the social sciences in computational models.
26 November 2025
Dr. Maria Gerullis, Department for Agricultural Economics and Rural Studies, University of Göttingen (Germany)
Economics of Social-Ecological Diversity: Governance Pathways for Crop Genetic Resource Systems
Crop genetic resource systems are complex, nested systems that comprise multiple levels of human and resource interactions, from individual crop varieties to entire genetic pools of crops. The governance of these systems has significant implications for the conservation and utilization of crop genetic diversity, which is essential for sustainable agriculture and food security. This presentation explores some of the economics of social-ecological diversity in crop genetic resource systems across multiple levels, examining how nested systems shape diversity outcomes through their multi-level incentive structures. Through the lens of seed choice and the evolution of the seed industry in Germany we will illustrate how different mechanism have impacted genetic diversity of major crops over time. We will discuss the implications of this trend for the long-term sustainability of these cropping systems.
03 December 2025
Dr. Karin Mora, Institute for Earth System Science and Remote Sensing, Leipzig University (Germany)
Phenoplexity: Phenology of the Future
Plant phenology studies short-term dynamics, such as daily and seasonal changes, measured on the ground as well as with satellite sensors. However, what does an observation of an individual plant, recorded via a smartphone using apps such as Flora Incognita, tell us about the wider plant community or ecosystem, and how well they cope with the impact of climate change? To answer such questions, we have to adapt machine learning approaches typically developed using synthetic data to work with these complicated, noisy, real-world datasets: from analysing time series under driving forces to linking observations from different sources—such as country-scale citizen science data, satellite-derived vegetation indices, and eddy-covariance flux tower data—across species and spatial and temporal scales.
I will give an introduction to these multi-scale plant phenology measurements before discussing specific methodological challenges in time series analysis, such as extracting dynamical characteristics of the seasonal cycle in noisy data using dimension reduction approaches, and the use of neural networks for modelling vegetation responses. I will show how these approaches can reveal surprising patterns of synchrony and asynchrony across species and on a country-wide scale.
Ultimately, this work aims to predict ecosystem responses to climate change and improve our understanding of feedback mechanisms and plant resilience at global scales, as well as whether biodiversity can have mitigating effects. I will discuss how, on the one hand, big data can help overcome knowledge gaps and yield spatio-temporal patterns, and on the other hand, how it can pose significant computational limitations that themselves constrain the types of system-level questions we can currently ask.
10 December 2025
(online) Dr. Maria Claudia Lopez Perez, Department of Community Sustainability, Michigan State University (USA)
The use of visioning to co-create energy systems for the Amazon
Approximately, one million people in the Amazon live in off-grid communities where electricity is either unavailable or limited to diesel generators. To expand energy access in a fair and sustainable way, participatory processes that emphasize energy justice and energy sovereignty are essential. In this presentation, María Claudia will share results from a project she have led in the Brazilian Amazon over the past four years, namely, a participatory co-design project involving visioning in which community members were actively involved at every stage of energy-system development — planning, dimensioning, installation, training, and management. The resulting systems combine photovoltaic panels, hydrokinetic turbines, and microgrids to enhance reliable and locally governed energy access.
17 December 2025
Prof. Dr. Dr. Johannes Halbe, Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB) and University of Osnabrück (Germany)
Systems Approaches for Steering Transformational Change
Given the scale of today’s social and environmental challenges, solutions require structural change rather than incremental problem‑solving. Transformative research seeks to foster such change by actively supporting innovations and generating three complementary types of knowledge: systems knowledge, target knowledge, and transformation knowledge. This talk will present a range of systems approaches and examine their potential for transformative research, with particular emphasis on methods for visioning, vision assessment, and steering multi‑stakeholder processes. Two case studies on groundwater pollution and sustainable universities will illustrate how these methods can be applied. Although the case studies address different topics (i.e., an environmental problem and an organizational issue), they reveal commonalities that can point toward general insights for steering transformative change.
07 January 2026
Dr. Stefanie Lutz, Utrecht Univerity (The Netherlands)
The hidden complexities of sustainable water quality management
Water quality is often an overlooked aspect in current sustainability challenges. This is partly due to legacy effects, i.e., the delayed impact of contamination on water bodies due to contaminant retention in soils and long transport times in groundwater. Moreover, problems related to water quantity (e.g., droughts and floods) are often more visible than those related to water quality (e.g., pesticides in drinking water resources). Hence, linking human activities and mitigation measures to their impact on water quality is not straightforward. In this talk, I will present novel modelling approaches for nutrients and pesticides incorporating legacy effects. Moreover, I will highlight ongoing research on reducing legacy pollution from nutrients and PFAS through nature-based solutions and sustainable remediation strategies. The talk will end with a broader perspective on sustainability challenges in the cut-flower sector, illustrating how water quality issues are embedded in a complex system of socio-economic, environmental, and human health factors.
14 January 2026
Dr. Elke Kellner, Hochschule Luzern (Switzerland)
Fast-Track Procedures to Mitigate Climate Change: Are We Really Accelerating Towards Sustainability? A Perspective Informed by a Relational Approach
Fast-track procedures are increasingly used worldwide to accelerate permitting and approval processes for climate-relevant infrastructure in response to the urgency of climate change. Infrastructure for climate mitigation is characterised by complex spatial and temporal trade-offs, which frequently give rise to local conflict, resistance, and justice-related concerns. These dynamics often contribute to prolonged planning and approval processes, despite the importance of timely implementation for achieving climate targets. Fast-track procedures are therefore introduced as a governance response aimed at reducing delays and increasing implementation speed.
This talk examines fast-track procedures as a global governance trend and highlights how acceleration efforts are commonly accompanied by shifts away from polycentric governance towards more centralised decision-making under time pressure. Drawing on a perspective informed by a relational approach, the presentation argues that acceleration does not necessarily require procedural centralisation or the curtailment of participation. Instead, it shows how strengthening relational capacities can contribute to navigating trade-offs and mitigating escalation dynamics, thereby enabling speed without abandoning polycentric and participatory governance arrangements.
21 January 2026
Dr. Jonathan Donges, Potsdam Institute for Climate Impact Research (PIK) (Germany)
Cascading interactions between climate and social tipping elements in the Anthropocene Earth system: Risks and Opportunities
Tipping elements in the Earth's climate system are continental-scale subsystems that are characterized by nonlinear threshold behavior. These components include biosphere elements, such as the Amazon rainforest and coral reefs; cryosphere elements, including the Greenland and Antarctic ice sheets; and large-scale atmospheric and oceanic circulations, such as the thermohaline circulation, ENSO, and Indian summer monsoon. Once operating near a threshold or tipping point that may be approached due to anthropogenic climate change, these components can transgress into a qualitatively different state by small external perturbations. The substantial environmental repercussions could potentially affect the subsistence of millions of individuals.
In this colloquium, Dr. Jonathan Donges will present a report on recent research on the risks of climate tipping elements, their potential effects on overall Earth system stability and resilience, and the interactions between climate tipping elements and the risk for resulting tipping cascades. Furthermore, the presentation will address the potential for positive societal tipping dynamics to facilitate the rapid decarbonization of the world's social and economic systems. This is necessary to achieve the stabilization of the Earth's climate in accordance with the objectives of the Paris Climate Agreement. In conclusion, the speaker will present a discussion on the emergent feedback dynamics of co-evolving potential climate and social tipping elements. This discussion will include the risks of destabilizing effects that are key to understanding polycrisis dynamics and global systemic risks in the Anthropocene.
