Grasslands are the Cinderella of environmental protection; they are often overshadowed by more favoured environments such as forests or heathland. However, there is a growing awareness among ecologists of the strong links that exist between above- and belowground parts of grassland ecosystem. Under the strong and persistent heavy metal contamination significant functional shifts in grassland ecosystems may result from disturbances of both their above- and below compartments. The aim of the project is to evaluate the impact of heavy metal contamination on the relative contributions of bottom-up and top-down forces acting within and between the different compartments of grassland ecosystems. The identification of the key components and the tracing of the nutrient flow will improve our understanding of the human impact on their functioning and persistence. The identification of sensitive indicators must enable us 1) to recognize early changes in the structural and functional components of the ecosystem and 2) to assess the health status.