Ecohydrology emerges as a new field of research aiming at furthering our understanding of the earth system through the study of the interactions between the water cycle and vegetation. By combining the analysis of biotic and abiotic components of terrestrial ecosystems, this volume provides a synthesis of material on arid and semiarid landscapes, which is currently spread in a number of books and journal articles. The focus on water-limited ecosystems is motivated by their high sensitivity to daily, seasonal, and decadal perturbations in water availability, and by the ecologic, climatic, and economic significance of most of the drylands around the world. Conceived as a tool for scientists working in the area of the earth and environmental sciences, this book presents the basic principles of eco-hydrology as well as a broad spectrum of topics and advances in this research field. The chapters collected in this book have been contributed by authors with different expertise, who work in several arid areas around the World. They describe the various interactions among the biological and physical dynamics in dryland ecosystems, starting from basic processes in the soil-vegetation-climate system, to landscape-scale hydrologic and geomorphic processes, ecohydrologic controls on soil nutrient dynamics, and multiscale analyses of disturbances and patterns.