The project is located at the convergence of three disciplinary directions: biogeochemistry of metals, ecotoxicology of metals and mathematical modeling of the bioremediation of contaminated areas. A major priority in the biogeochemistry of metals is the coupling of knowledge at micro scales with that of metal cycling processes at the scale of socio-ecological systems. A research priority in the ecotoxicology of metals is the expansion of knowledge about the effects of metals through research in ecosystems and real ecosystem complexes, on a large scale. modeling in bioremediation is a research direction in itself, closely related to the previous ones because: 1) contaminated sites are complex ecosystems, 2) modeling requires the existence of some knowledge of biogeochemistry and ecotoxicology, bioremediation actions can be seen as relevant in situ experiments for studying cycling and the effects of metals. In this context, the project proposes the construction of a coherent portfolio of holistic and mechanistic models at meso and macro scales about the cycling of metals in two complex ecosystems: one intensely polluted, the other with moderate pollution. The meso level is approached experimentally using lysimeters with undisturbed soil, and the macro level is approached through field research of local biogeochemical circuits. Beyond the character of fundamental research, the results of the project will be directly relevant for practical problems such as toxicological and ecotoxicological risk assessment, bioremediation strategies and the design of the metabolism of socio-ecological systems. The project will be implemented in close cooperation with a German consortium of research centers in the field of biogeochemistry of metals in contaminated areas.