Kerstin Wiegand		Ecosystem Modelling University of Göttingen
Home Curriculum Vitae Publications Research Teaching Links		General reserach concepts Spatial ecology The spatial distribution of organisms and resources is important for understanding many ecological questions, making spatial ecology a promising field of research. My work has a strong methodological emphasis on spatial simulation models (always in combination with field research) and spatial statistics (based on field data or remote sensing).  Biocomplexity The dynamic behaviour of ecosystems emerges from interaction at multiple spatial and temporal scales. From my point of view, a key to understanding ecosystems is to investigate the same system from changing viewpoints, i.e. at a range of spatial and temporal scales. By understanding pattern formation at different hierarchical levels, one may disentangle step by step how local effects translate into global behaviour of complex ecological systems and vice versa. Nature conservation I started my career as an ecologist doing population viability analyses of plant and animal species. Since then, Nature Conservation is still the guiding principle and ultimate goal behind my research. In projects related to say biodiversity, savanna ecology or plant ecology, I aim at understanding basic mechanisms and using this basic knowledge to derive scientific fundamentals of nature conservation.  Main current research topics Biodiversity in cultural landscapes Species richness is determined by evolutionary history, ecological processes, and management. I'm specifically interested in understanding how ecological processes at different spatial scales affect biodiversity and how this interacts with management and human welfare. Recent projects include: CRC 990: Ecological and socioeconomic functions of tropical lowland rainforest transformation systems (Sumatra, Indonesia) (Projects B10, Z01, Z02) ELUC: Integrated modelling of land-use changes at rainforest margins in Indonesia STRUCTURE: The effects of land-use and structural heterogeneity on biodiversity: A new assessment method using cost-effective remote sensing and fine-scale pattern analysis BEAM: Towards a mechanistic understanding of biodiversity and its functional consequences - the biodiversity exploratory additional modeling component Savanna ecology Savannas are ecosystems where a mixture of two contrasting life-forms, trees and grasses, is dominant. Looking for the mechanisms maintaining tree-grass coexistence, I have developed the hypothesis that tree-grass coexistence can be explained by viewing savannas as patch-dynamic systems composed of many patches in different states of transition between woody and grassy dominance. This hypothesis also puts the phenomenon of bush encroachment (suppression of palatable grasses and herbs by encroaching woody species forming impenetrable thickets) into new light. Bush encroachment can be a natural phenomenon and cannot exclusively be attributed to mismanagement. In collaboration with David Ward, I have found ample evidence for patch dynamics in arid savannas, both based on data and modeling. Next steps will be to test the hypothesis in moist savannas and to understand its socioeconomic consequences. Plant ecology How do plants establish, grow and die? How do plants interact with each other in terms of competition and facilitation, and how do plants interact with animals? How do these patterns change with changing abiotic environments? Answers to basic questions such as these form the basis for research into more complex problems because any plant ecological model involves assumptions on spatiotemporal dynamics and interactions. My research in this direction has always been geared towards trees and, having moved to a forestry department, it now has a focus on ecology of forest trees. Recent projects include: RTG 1086: The role of biodiversity for biogeochemical cycles and biotic interactions in temperate deciduous forests RTG 1644, P8: The role of heterogeneity in spatial plant population dynamics Main methods Ecological modelling and Spatial statistics My lab members and I have special expertise in Ecological modelling (individual-based models, agent-based models, grid-based models) and Spatial statistics (Point pattern analysis). However, we are always happy to wander off and use other methods such as matrix modelling or to collect field data if this appears to the most promising route to finding answers to an interesting question.  Recent projects include: RTG 1644: Scaling problems in statistics