Water is an essential resource for life on earth and all living organisms depend on it. The biota, in turn, affects the dynamics of major hydrological processes, thereby determining the rate of the water cycle. Research in ecohydrology focuses on interactions between ecological and hydrological processes. These interactions are particularly strong in the case of dryland ecosystems, where water availability is the main limiting factor to vegetation dynamics and ecosystem primary production. This paper provides a review of the main hydrological processes affecting ecosystem dynamics, as well as of the ecological processes controlling the water cycle on the earth.
