structure > project group C > scientific project C3Scientific Project C3 - Measuring and modeling surface structures as determinants and results of the primary succession of an ecosystemThe Project C3 comprises a metrological descriptive part, and a part which aims for constructing a simulation model. Both parts contribute to testing all five of the SFB/TRR’s central hypotheses. The metrological part aims for measuring the spatial structure of the terrain surface and the vegetation in monthly intervals and to statistically describe their states and changes. A terrestrial laser scanner is used to obtain this three-dimensional information in the high resolution desired. Thus, all other projects in the SFB/TRR can be supplied with quite up-to-date information concerning the state of surface structures in the investigation area. The modelling part of project C3 is closely connected to the metrological approach. Data and research results in C3 as well from the other projects are used to build a spatially explicit simulation model in order to cover the feedback between vegetation and surface dynamics. The role of this model is to be seen as a means of up-scaling high resolution (in a temporal and spatial sense) insights to somewhat coarser temporal and spatial scales. On the other hand, the model can serve to generate frame scenarios for high-resolution model approaches in other projects which for example also deal with subsurface processes. The model’s core idea is to simulate the feedback between vegetation dynamics (biomass accumulation, succession, dispersion) and terrain surface dynamics. It’s the goal of the simulations to contribute to a deeper understanding of the geared development of surface and vegetation patterns. Thus, the model helps to reject or accept the central hypotheses of the SFB/TRR. With the model development we strive for bundling and structuring detail knowledge and for supporting the scale-transfer of knowledge. The model is intended to be useful for areas of some 100 m² up to the size of the investigation area. The spatial resolution can vary between 0.5 and 10 m², the temporal resolution varies between monthly and annual intervals. The time horizon for scenario simulations is five up to 25 years. The model is a cellular automaton. The area of interest is covered with a quadratic raster, where the size of a single raster cell constitutes the highest spatial resolution. For each cell a set of variables concerning terrain height, substrate and vegetation is defined which may change during a simulation. Neighbour cells interact in terms of e.g. plant competition, plant dispersion, material transport. Inside each cell the model reflects the most important (more precise: most important considering the model’s spatial and temporal resolution) feedback loops concerning vegetation dynamics and their interaction with the surface.
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