Dr. Stephen Wirth

I hold a PhD in agricultural sciences from Kiel University and am a postdoctoral researcher in the Land Biosphere Dynamics group (LBD) at the Potsdam Institute for Climate Impact Research (PIK). My work sits at the intersection of ecosystem science, biodiversity, and land-based climate mitigation.

During my PhD, I investigated how functional diversity in managed grasslands shapes forage supply, soil organic carbon, and biogeochemical cycles. The core of this work was integrating CSR theory and simplified trait-based approaches into the dynamic global vegetation model LPJmL — enabling explicit large-scale simulations of how plant community composition mediates grassland responses to changing climate and management.

Land-based carbon dioxide removal (CDR) and carbon farming are now at the centre of my postdoctoral research. As part of the CDRterra initiative, I contributed to the ABCDR project, where I used LPJmL to assess the biophysical CDR potential of agroforestry systems across different climate and land-use scenarios. I now coordinate CDRfarm, which investigates the permanence of carbon stored through different farming practices under future climate change, including overshoot scenarios, and develops decision support tools to evaluate and compare a portfolio of carbon farming options — bridging process-based modelling with the practical needs of land managers and policymakers.

Across all my work, I bring strong expertise in model development — including contributions to lpjmlkit and lpjmlstats, the open-source R toolkits for LPJmL — and am expanding into hybrid modelling, combining mechanistic and machine learning approaches. My broader research interests include ecosystem functioning, animal-plant interactions, biodiversity, and functional ecology.