Samia Ghersheen

I am a mathematician working on nonlinear dynamical systems in biology, developing and analysing process-based models to understand how mechanisms and feedbacks shape long-term behaviour in complex biological systems.

My research lies at the interface of mathematics and biology. I use a mathematical lens to understand how biological systems evolve over time, why they remain stable, when they undergo abrupt shifts, and whether recovery is possible.

Across applications ranging from infectious disease dynamics to microbial ecology, I work with nonlinear dynamical systems to understand how biological mechanisms and feedbacks generate observed patterns. My work combines qualitative analysis, such as stability and bifurcation analysis, with quantitative approaches, including data-informed parameterisation and empirical evaluation.

In my current project, I work with process-based mathematical models of litter decomposition to investigate how fungal adaptation to nitrogen limitation shapes long-term decomposition dynamics in forest soils.

•  Ghersheen, S., Manzoni, S., Spohn, M., & Lindahl, B. D. (2025). Modelling mycelial responses to nitrogen limitation during litter decomposition. Soil Biology and Biochemistry, 109899.
• Schwarz, E., Ghersheen, S., Belyazid, S., & Manzoni, S. (2024). When and why microbial-explicit soil organic carbon models can be unstable. Biogeosciences, 21(14), 3441-3461.
• Andersson, J., Ghersheen, S., Kozlov, V., Tkachev, V. G., & Wennergren, U. (2021). Effect of density dependence on coinfection dynamics. Analysis and Mathematical Physics, 11(4), 166.
• Andersson, J., Ghersheen, S., Kozlov, V., Tkachev, V. G., & Wennergren, U. (2021). Effect of density dependence on coinfection dynamics: part 2. Analysis and Mathematical Physics, 11(4), 169.
• Ghersheen, S., Kozlov, V., Tkachev, V. G., & Wennergren, U. (2019). Dynamical behaviour of SIR model with coinfection: the case of finite carrying capacity. Mathematical Methods in the Applied Sciences, 42(17), 5805-5826.
• Ghersheen, S., Kozlov, V., Tkachev, V., & Wennergren, U. (2019). Mathematical analysis of complex SIR model with coinfection and density dependence. Computational and Mathematical Methods, 1(4), e1042.