Owing to man-made intervention, the shrub-steppe now represents a rapidly disappearing landscape in the arid regions of North America. This book represents a systems-level study of ecological variables affecting water balance, and responses to perturbation. The study focused on a very large, protected, landscape unit, comprising a natural ``watershed'' area located in the semi-arid western United States. Long-term and concurrent data sets were established with a view towards establishing system-level responses to manipulative interventions, and natural perturbations like wildfire. These data sets were established for micrometeorology, climatology, mineral cycling in soils, nutrient and mineral pathways in springs and streams, vegetational dynamics, and population changes on the site. In synthesizing nearly twenty years of data, the more interesting ecosystem level responses concerned vegetational recovery and water balance. For instance, the synthesis uniquely demonstrates the interaction of biotic and non-biotic factors and their integrated effect on regional water balance. However, special attention was also paid to species diversity and the genetic resource pool represented at this site.This book will be of primary interest as a reference resource to land managers and wildlife specialists, and as a research study for scientists interested in systems-level ecology. Conservation-minded citizens who take more than a cursory interest in ecology will also find it interesting.