This book studies the application of green roofs in ecoregions of the western United States and Canada. While green roofs were intended to sustain local or regional vegetation, this volume describes how green roofs in their modern form are typically planted with a low-diversity mix of sedums from Europe or Asia. The authors demonstrate how in the western USA and Canada many green roofs have been designed with native plants and have been found to thrive. Part I of this book covers theory and an overview of ecoregions and their implications for green roofs. In Part II vegetation from prairies, deserts, montane meadows, coastal meadows, and scrub and sub-alpine habitats are explored on seventy-three ecoregional green roofs. Case studies explore design concepts, materials, watering and maintenance, wildlife, plant species, and lessons learned. Part III covers an overview of ecoregional green roofs and a future outlook. This book is aimed at professionals, designers, researchers, students and educators with an interest in green roofs and the preservation of biodiversity.