Running water ecosystems — a bare field for modelling?

The development and the present state of running water limnology is briefly reviewed. Spatially, the importance of the vertically three-layered structure of most streams is stressed, as well as the importance of riparian forests and flood plains. Temporally, emphasis is laid on the impact of stochastic hydrological events and the distribution, size and dynamics of patches. A consideration of chaos theory in modelling stream ecosystems is suggested.