Soil as part of the ecosystem is strongly interrelated with plants and animals living on the soil. Consequently, soil properties influence the composition of the symbiosis. Vice versa, plants and animals may alter soil properties and have an impact on the edaphic geodiversity on various spatial scales. Both biodiversity and edaphic geodiversity (pedodiversity) are to a great extent determined by geology, topography, climate and human activities.

The five work packages of this subproject aim at the understanding and explanation of the above mentioned factor constellation. By the co-operated investigations with a standardised procedure along a climate gradient from the Cape region to northern Namibia the mutual dependencies between pedodiversity and biodiversity will be analysed and tested by index based comparisons. Two work packages concentrate on functional aspects of soil properties as driving factors on plant and animal distribution and on erosion processes. To test the causes of existing erosion phenomena investigations will focus on the development and ecological function of soil sealing crusts. The effects of land utilisation on soil properties and their (positive or negative) effects for biodiversity will be investigated by the comparison of paired Observatories with different forms and intensities of land use. The assessment of soil properties on the farming system level will facilitate a continuous interpretation of the different scales of investigations on biodiversity and on the socio-economic issues. This will be achieved by the use of satellite and airborne image data for the soil survey. Furthermore, the assessment of soil properties will contribute to restoration and management experiments carried out within other BIOTA Southern Africa subprojects.

With the knowledge of the function of the soil as a factor for plant / animal key species, biodiversity and economic land use, it will be possible to develop suitable land use concepts which will facilitate sustainable protection of both, soil quality and biodiversity.