Extrapolation through hierarchical levels.

1. Translating results from low hierarchical levels to higher orders meets with difficulties with respect to temporal, spatial and organizational scales. 2. Translating stress effects through hierarchical levels has not yet been possible, thus hampering ecological risk assessment. 3. Three approaches to link the various levels are described; the energetics, the endpoint and the minimal structure approach. 4. A concept to integrate these approaches to enable extrapolation of stress across hierarchical levels is described.