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Research Projects

Simulation models in ecology are useful tools to investigate patterns and processes at spatial and temporal scales that are impractical to study in the field of laboratory. Manipulations of whole landscape structures or the long-term management effects on ecosystems are examples that are very difficult to study in real systems.
My idea of ecological modeling is to gather the knowledge that is available and cast it into a simulation that models a specific part of the real system. I usually work closely together with field ecologists and make sure that the model inputs and outputs are comparable to actual field data. Ideally, the model helps then to untangle important ecological processes that may act at different spatial and temporal scales. The aim of ecological modeling is to improve ecological theory and find possible explanations of patterns found by field ecologists. Also new ideas for lab experiments and/or field studies can emerge from simulation experiments.
I often use pattern-oriented approaches and develop my models in C++ and NetLogo.

Ground beetle model

simulated ground-beetle subpopulations on a landscape The aim of this project is to better determine and understand the influence of different landscape characteristics on biodiversity. The idea is to develop a spatially explicit multi-species simulation model with stochastic birth, death and dispersal processes. The empirical basis for the model is previously collected data on different taxonomic groups of invertebrates in agricultural landscapes. Status: Current project. For starters we simulate ground-beetle populations on artificial landscapes where we can completely control the landscape measures like landscape configuration and composition.
Cooperations: Katrin Meyer, Teja Tscharntke, Kerstin Wiegand

Fairy Circles

competition-facilitation heatmap of simulated fairy circles Fairy circles are circular bare patches that form strikingly regular patterns over huge areas. They occur in the millions in parts of Namibia, South Africa and Angola. Despite years of research, the origin of the fairy circles still remains unclear. With our fairy circle simulation model, we aim to identify and understand processes that may cause the genesis and maintenance of fairy circles based on spatial self organization.
Status: Current project. Bachelor thesis of Theresa Möller-Lindenhof: Ecological drivers of fairy circle patterns in dryland vegetation (supervision together with Stephan Getzin and Katrin Meyer).
Cooperations: Stephan Getzin, Katrin Meyer, Kerstin Wiegand

Molopo

simulated vegetation dynamics due to intense grazing around a watering point Land degradation and desertification are serious threads to extensively farmed arid and semiarid savanna rangelands. Land degradation processes such as bush encroachment and loss in vegetation cover are strongly influenced by the applied farming practice, but it is very difficult to identify the actual causes and effects in such complex ecosystems. Computer simulation models can be valuable tools to help to better understand the complex processes of rangeland dynamics under different management scenarios.
During my diploma thesis we developed a spatially explicit, grid-based based rangeland simulation model which allows simulations on real landscape data. The model is able to resemble vegetation patterns as the formation of a specific sequence of vegetation types along a gradient of different grazing intensity - a so-called piosphere. The model is adaptable for different management (i.e. stocking rate, livestock composition, camp rotation) and climatic scenarios (spatio-temporal precipitation pattern, temperature).
Status: Kick-off model for a follow-up project: IDESSA.
Cooperations: Klaus Kellner, Theunis Morgenthal, Kerstin Wiegand, Thorsten Wiegand

Tiger bush

simulated tiger bush vegetation on a slope gradient Tiger bush is a striped (or banded) vegetation pattern that is caused by local facilitation and not-only-local competition for water. It occurs on slight slopes and the vegetation bands are parallel to the contour lines. The idea of this model is to make the slope variable and include adjacent ecotopes without slope to better understand the development (and conservation) of tiger bush. The model is based on the TIGREE-model.
Status: This model was part of a term paper during my studies in mathematical biology in Jena.