Soil protection, restoration and revitalisation are becoming a priority in European Union strategies. Soil protection to date has been based mainly on the measurement and use of soil physical and chemical properties and research into the ecology and ecotoxicology of individual species or taxonomic groups. Until now, the biotic factors of the pedosphere have rarely been considered as distinguishing features for soil characterisations and classifications. In the last twenty years, the importance of ecological functions as crucial components of ecological services and as important factors for the stability of ecological soil systems has been recognised. The primary hypothesis of this proposal is that soils may differ from each other in terms of their taxonomic and functional biodiversity. Furthermore, we hypothesise that differences in these biodiversities are also highly correlated with the biotic potential of individual soils and that ecological stability is related to the range of ecotoxicological tolerance. A special focus of the research is on arsenic, a naturally occurring element in the soils of Croatia. In addition to new knowledge, this proposal includes an innovative approach to research methodology, using high-performance scientific computing to conduct in silico experiments. Such a research methodology enables the optimisation and fully adaptive design of experiments, ensuring predictability of the research process and results yield. The expected results will make a scientific contribution to ecology and ecotoxicology in terms of quantification and research methodology of ecological functions in soils. The applied significance of the results will be in agriculture and forestry, in the part that deals with maximum soil conservation. An exceptional contribution of the planned research is expected in the recommended methods and measured parameters, which will serve as a basis for harmonisation of Croatian legislation within the legal framework of the EU.