CASUS Institute Seminar, Dr. Thorsten Wiegand, Deputy Head of Department of Ecological Modelling, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
Abstract of the talk// Ecologists have tried for long to explain coexistence of many competing species in communities such as tropical forests. The overarching objective of the new project “SpatioCoexistence” financed by an European Research Council Advanced Grant is to develop a spatially-explicit theory for understanding the dynamics and stability of plant communities. A key task of the project is to develop methods to transport critical information across scales. For example, spatial patterns such as intraspecific clustering and interspecific segregation, which emerge from neighborhood effects occurring at the “microscopic” scale of individual plants, may play an important role in diversity maintenance of plant communities at a “macroscopic” scale.
Thorsten will present an upscaling approach where the macro-scale interaction coefficients of traditional Lotka-Volterra multispecies models become a function of micro-scale interaction coefficients and indices of the emerging spatial patterns. These “transfer functions” are derived from upscaling neighborhood crowding indices that describe neighborhood competition for individual trees. Information gathered from fully stem-mapped data of the ForestGEO network allow, together with individual-based simulations, for model parameterization. The resulting macroscopic models that incorporate the transfer functions approximate the underlying detailed individual-based model, and allow for studying the role of pattern-generating microscopic mechanisms and processes on macro-scale community dynamics and stability. The individual-based models are important to verify that the hypothesized mechanisms and transfer function approximations work as expected, and they allow for extending the theory into the analytically intractable domain.
CV// Thorsten received a PhD degree in Theoretical Ecology from the Department of Physics at Marburg’s Phillips-University (Germany) in 1992. In 1999, he finished his habilitation in Theoretical Ecology at the Faculty of Forest Science of Ludwig-Maximilians University (Munich, Germany). Working since 1992 at the UFZ’s Department of Ecological Modelling, he is currently the Deputy Head of the department.
Thorsten will be talking live in Görlitz. However, as the event is organized in a hybrid format that includes a videoconferencing tool by Zoom Inc., people interested in the topic have the chance to also join the talk remotely. Please ask for the login details via contact@casus.science.