A state-of-the-art overview of the influence of terrestrial vegetation and soils within the Earth system. The text deals especially with interactions between the terrestrial biosphere and the atmosphere via the hydrological cycle and their interlinkage with anthropogenic activities. Measurements gathered in integrated field experiments in the Sahel, the Amazon, North America and South-east Asia confirm the importance of these interactions. Observations are complemented by modelling studies, including regional models that simulate flows and transport in river catchments, coupled land-cover...