As the soil is one major compartment of terrestrial ecosystems, soil parameters to a great extent influence the composition of flora and fauna. In this project it is aimed to analyse the mutual dependency of the soil as a controlling factor of biodiversity and vice versa. This is to be analysed along the entire BIOTA transect following a large continental climatic gradient which spans over high geodiversity. In order to document this diversity with respect to the soil a useful inventory in the methodology has to be established. This includes the selection and proof of useful indicators to document the influence of soil parameters on the biodiversity. An over-all aim - in the long term perspective - is to develop various concept for a sustainable use of the soil in close co-operation with agriculture and forestry. Here various land use practises in southern Africa should be taken into consideration.
The main focus will lie on the inter-disciplinary approach to analyse the structures, reasons, processes, and impacts of biodiversity along a gradient-orientated transect. The hypothesis that a higher variability in abiotic parameters in a given area will necessarily lead to a higher biodiversity is to be proofed. For this project based on soil science it has to be considered that abiotic parameters are of varying importance to flora and fauna depending on the biotic group to be analysed. Therefore, next to a standardised documentation of the geodiversity of the Observatories along the transect, the problem of scale will be considered. Different scales have to be applied when analysing (a) changes in soil parameters within changes in vegetation units, (b) analysing the effect single bushes or trees have on animals (shading effect) or (c) on plants (safe sites for germination). Here, it has to be analysed whether or not a systematic nutrient / salt accumulation takes place, what effects small burrowing mammals create on soil properties and if soil crusts by cyanobacterias or lichens have an impact on the nutrient cycle of the soil. Thus, this project forms an important link between the various biotic aspects (fauna, vegetation, lichens, crusts, fungi) within the BIOTA project. Furthermore, the impact of different land use practises on the geodiversity will be analysed. Here, focus will lie on the impact on the water and nutrient cycle of the soil.