Birgit Müller

Name: Prof. Dr. Birgit Müller

Position: Head of the Junior Research Group POLISES


Keywords: Socio-environmental and agent-based modelling, human decision making, sutainable agriculture, food security, degradation, livestock

Personal web page

Birgit has a background in economic mathematics (University of Leipzig) and holds a PhD from the Institute of Environmental Systems Analysis, University of Osnabrück. Since April 2022 she holds a joint chair at Brandenburg University of Technology Cottbus on "Modelling of Human-Environment Systems". During her research at the Helmholtz Centre for Environmental Research – UFZ in Leipzig she was engaged in different interdisciplinary research projects with ecologists, geographers and economists. In these projects she used socio-environmental modelling and in particular agent based modelling to explore impacts of human land use decisions on livelihood security and sustainability. Case studies focus firstly on the impact of policy instruments related to agrienvironmental schemes and nitrogen use in European agriculture and secondly on land use strategies to cope with climate risk in Europe and semi-arid regions of Africa.

Birgit likes exploring nature and using wild plants for cooking and colouring wool.

Gunnar Dreßler

Name: Dr. Gunnar Dreßler

Position: Postdoc


Keywords: agent-based modelling, mobility, polarization, human decision making, resilience, remote sensing

Personal web page

Gunnar is a Postdoc at the Department of Ecological Modelling of the Helmholtz Centre for Environmental Research. Within POLISES, he focuses on aspects of mobility of pastoralists and livestock and how polarization between different pastoralist groups can arise, respectively how policy instruments can be used to reduce the inequality between poor and rich herders. He is also interested in the representation of human decision making in agent-based modelling.

In 2010 Gunnar joined the UFZ and has since then worked in the collaborative research centre “Difference and Integration” and the EU FP7 research project “emBRACE – Building Resilience Amongst Communities in Europe”. He graduated from the University of Greifswald in 2011 and holds a Diploma in Biomathematics. For his Diploma thesis he worked with researchers of the University of Maryland on an analysis of spatial and temporal patterns of global vegetation dynamics, using remote sensing data. Gunnar loves photography, good coffee and trying out new delicious baking recipes.

Julia Kunkel

Name: Julia Kunkel

Position: PhD


Keywords: agent-based modelling, insurance products, agricultural policies, human decision making, grassland

Personal web page

Julia is a PhD in the InsuranceGrass project where she explores side and substitution effects of different insurance options for grassland farmers. Within this interdisciplinary project she is working closely together with geoecologists, economists and political scientists to develop an agent-based model. With a background in business mathematics and sustainability management, for her master's thesis Julia developed a two-stage stochastic formulation for an energy system optimization model to include the balancing reserve market.

Julia is passionate about sports and exploring nature in all seasons. She loves (up)cycling, swimming and drinking green tea.


Kaja Jurak

Name: Kaja Jurak

Position: PhD


Keywords: agent-based modelling, human decision making, sustainable agriculture, fertilizer management


Kaja is a PhD student and is interested in the model-based exploration of leverage points to foster sustainable nitrogen management in German agriculture. She did her masters in mathematical physics in Würzburg where she worked on the multi-scale analysis and ill conditioning of the inverse problem of chemotaxis in the Bayesian setting.

Kaja likes hiking, bouldering and working with animals. She is also doing an education as a dog trainer.


Jonathan Haag

Name: Jonathan

Position: Student assistant


Keywords: hay market, network optimization


Jonathan is a student resarch assistant and is interested in the effect of different forms of market organisation on the drought resistance of grassland farmers using methods from network science and optimization.

He is doing his masters in simulation technology in Stuttgart with a focus on data-driven methods for the modelling, optimization and control of dynamical systems.

Jonathan likes hiking, bouldering and reading. He is also frequently trying out new plant-based dishes.



Annika Backes

Name: Annika Backes

Position: Master’s student

Annika has studied Economics and Management Science at the University of Leipzig and is currently finishing her Master’s degree in Economics with a focus on Applied Econometrics. Her research interests are economic and social interdependencies and the impact of regional economic performance on political preferences. She joined POLISES to write her master’s thesis on the effect of networks on the diffusion of microinsurance products.

In her free time, Annika enjoys cooking, going to the theatre and spending time outside.

Hendrik Gelsmann-Kaspers

Name: Hendrik Gelsmann-Kaspers

Position: Master’s student

Duration: December 2016 - December 2017

Hendrik studies Environmental Systems and Resource Management at the University of Osnabrück. In 2017, he wrote his master thesis at POLISES, in which he compares different risk-coping strategies of pastoralists with respect to their long-term ecological and economic impacts. He is interested in modelling human decision-making using the agent-based approach and in searching ways for a system transformation towards a sustainable world.

Hendrik likes football, reading the newspaper with a cup of coffee, and discussions of political and sustainability issues.

Filipp Grcondciel

Name: Filipp Grcondciel

Position: Master’s student

Duration: October 2017 - September 2018

Keywords: Socio-ecological-economic & agent-based modelling, poverty traps, human decision making

Filipp is a master's student in physics. He is interested in complex systems and system dynamics, particularly the application of mathematical-physical methods to socio-ecological problems. During his training he wants to learn something about the dynamics of poverty traps.

Filipp did his bachelor and is now working as a student assistant in the surface/interface science section in Halle (Saale). A scholarship from the Hans Böckler Foundation gave him the opportunity to study and engage in socio-political areas like intercultural exchange or anti-racism.

Lemlem Habtemariam

Name: Dr. Lemlem T. Habtemariam

Position: Research Fellow

Lemlem holds a PhD from the chair of Agricultural Production and Resource Economics, Technical University of Munich. Her research experience and interest lies on understanding the effects of climate change on agriculture, farmers’ climate change adaptation strategies, the impacts of agricultural technologies, farming practices and policies on farmers’ income and food and nutrition security. She joined the POLISES group in July 2019 for a short term research stay. During her stay at POLISES, she will focus on studying the effects of agricultural insurance on rural households food and nutrition security.

Niklas Hase

Name: Niklas Hase

Position: Research Assistant

Duration: January 2015 - August 2016

Keywords: Social Network Analysis, Risk-sharing Networks, Mathematics

Niklas Hase was a Research Assistant at the Department of Ecological Modelling of the Helmholtz Centre for Environmental Research for 20 months. From 2007 to 2014, he studied Mathematics at the University of Leipzig. Within POLISES, he explored social-ecological side effects of policy instruments in eastern Africa. To do so, he used Social Network Analysis to understand the interplay of informal insurance within risk-sharing networks of pastoralists and formal insurance schemes like index-based insurance.

Falk Hoffmann

Name: Falk Hoffmann

Position: Research Assistant

Duration: September 2017 - June 2018

Falk was studying physics in Tübingen when he joined the Department of Ecological Modelling (UFZ) for his Diploma thesis in 2014. Guided by Birgit’s supervision, he investigated polarization among pastoralists due to agent heterogeneity in an agent-based model of Gunnar’s. Afterwards, he left for modelling urban heating systems within the BMBF project “Energy-efficient city Delitzsch” and for gaining experience in evolutionary multi-objective optimization at the Department of Computational Landscape Ecology. Since autumn 2017, he has rejoined to help Birgit prepare an international workshop to be held in March 2018: “Modelling approaches to enhance food security: Synergies from bridging the gap between the micro and the macro scale.”

Apart from that, he is part of a community-supported agriculture project and plays ultimate frisbee. Further fields of interest include philosophy, some politics and alternative forms of society.

Felix John

Name: Felix John

Position: Research Associate

Duration: January 2015 - March 2018

Keywords: agent-based modelling, human decision-making, index-based insurance, sustainability economics

Personal web page

Felix holds an M.A. in Sustainability Economics, focusing on human-environment interactions (using agent-based models) and decision-making processes of boundedly rational agents. Felix joined the POLISES group in January 2015 and analyzes the economic and ecological (side-)effects of index-based insurance for East African smallholders. Other research interests include human decision-making in complex situations, agent-based modelling in the social sciences, the transition towards sustainability, and behaviourally-informed policy design.

Felix is a passionate singer in different choirs and likes playing racket sports (table tennis, badminton, squash).

Sophie Kerchnawe

Name: Sophie Kerchnawe

Position: Master’s student

Sophie studied mechanical engineering, specializing in aerospace engineering, at the TU Dresden and the TU Delft. She then spent 5 years in R&D in the automotive industry, where she worked on the industrial manufacturing of fibre-reinforced plastics. During this time she became more and more interested in design and the presentation of complex information. Now she is studying Information Design (M.A.) and is writing her master thesis in the POLISES group about the possibilities of communicating research results with the help of serious games. After her master thesis, Sophie wants to continue working in research and development with her new focus.

Photography is one of her most beautiful hobbies. She experiments a lot with blurring, so that her pictures are rather abstract and at first glance it is often impossible to recognize what she has photographed. She also enjoys meeting friends and is active as an alumna in the Erasmus student network ESN Alumni Deutschland e.V. and in the women's network Femtec.Alumnae e.V.

Anneliese Koppelt

Name: Anneliese Koppelt

Position: Research Assistant

Duration: October - December 2018

Anne has studied Economics and Psychology at the University of Halle (Saale). Since October 2018, she is a Master student at the University of Dresden in Psychology (Human Performance in Socio-Technical Systems). Anne is interested in sustainable behavior in terms of sustainable consumption and sustainable lifestyle. She joined the UFZ as an intern to support the research on behavioral economics. For modeling the heat sector until the year 2050, she researched heat-relevant behavior of industrial companies. Currently, Anne contributes to a literature research on farmers’ behavior. She will focus on theories of behavior and behavioral change which are foreseen for integration into agent-based modeling.

Martin Kraus

Name: Martin Kraus

Position: Research Assistant

Martin has studied Mathematics in Würzburg and Jena. After going deeper and deeper into abstraction for six years, he decided to have a closer look on application now. The topic of his internship at POLISES is how different types of farmer behaviour can change land use. He is strongly interested in methodological questions regarding agent-based modelling as well, and, being still at the beginning of his journey into applied sciences, he will broaden his interest and maybe find a topic and a supervisor for a PhD position afterwards.

In his spare time Martin likes making and listening to music, reading and social activities of any kind.

David Kreuer

Name: David Kreuer

Position: Project Assistant

Keywords: social geography, pastoralism, drought, youth studies, insurance

Personal web page

David has a background in Middle East Studies and Computer Science. From 2008-12, he was a member of Collaborative Research Centre 586 with the University of Leipzig and the UFZ. Apart from facilitating the administrative side of things for POLISES, he provides the modellers with qualitative insights and quantitative data from his empirical fieldwork among pastoralists in the eastern Moroccan steppes and the High Atlas mountains. In his spare time, David is active in a housing co-op and enjoys distance running.

Jakob Lochner

Name: Jakob Lochner

Position: Intern

Duration: October - December 2017

Jakob studies physics at the University of Leipzig and did his Bachelor at the University of Göttingen. In particular he is interested in techniques to teach complex topics from science. Thus he is doing an internship in the POLISES group and develops a concept for a web based learning game, which teaches secondary class students the global links between decisions of themselves as consumers and food security in the global south.

Jakob likes walking through nature, cooking and hiking in the mountains.

Khadijeh RahimiBalkanlou

Name: Khadijeh RahimiBalkanlou

Position: Guest Scholar

Duration: October 2018 - June 2019

Keywords: Socio-ecological systems, land use/land cover dynamics, degradation, ecosystem services, Urmia Lake

Khadijeh is a PhD student at the University of Kashan, Iran. She joined the POLISES group in October 2018 to spend her sabbatical period at the Helmholtz Centre for Environmental Research. During her stay at UFZ, she investigated the spatiotemporal dynamics of ecosystem services in the Lake Urmia basin which is threatened by degradation. In this regard, she used remote sensing and innovative methods such as ecosystem services assessment matrix. She also has a background of working with social networks analysis on rangeland stakeholders in Iran.

She is the manager of an NGO and active in environmental protection issues in northwestern Iran. Swimming is her favorite hobby and she enjoys reading books and going out with friends.

Andreas Ruby

Name: Andreas Ruby

Position: Intern

Duration: January - April 2016

I study Geography and NwT (natural science and technology) in Tübingen. Normally, with my studies, I'm going to be a teacher in secondary school, but for my orientation and knowledge I prefer to make my experiences outside of the educational system of Baden-Württemberg.

From January through April 2016, I was part of the POLISES group, working on (board) games about the issue of land use by smallholders in developing countries.

Meike Will

Name: Dr. Meike Will

Position: Postdoc

Keywords: agent-based modelling, human decision making, social network analysis, insurance products, agricultural policies

Meike was a Postdoc in the BESTMAP project where she focused on the implications of agricultural policies on the adoption of environmentally friendly farming practices. Meike has studied physics at the University of Leipzig and joined the UFZ for her Master thesis on microbial predator-prey systems in 2016. In her PhD project, she worked in the SEEMI project where she combined the approach of agent-based modelling with social network analysis to explore the effects of microinsurance on informal safety nets.

Tim Williams

Name: Tim G. Williams

Position: Research Fellow

Tim is a PhD student from the University of Michigan (Department of Industrial and Operations Engineering). For his dissertation research, he is using both agent-based modeling and empirical analysis to explore issues of risk and resilience in smallholder agricultural systems. He is generally interested in the intersection of these two forms of analysis. Tim joined the POLISES group from August-November 2019 for a short-term research stay. During this time, he developed a stylized simulation model to compare the effectiveness of leguminous cover cropping and index-based microinsurance in enhancing the climate resilience of smallholder households. He also brewed his own beer and enjoyed playing ultimate frisbee in the Leipzig parks.