As our world becomes increasingly urbanized, an understanding of the context, mechanisms, and consequences of city and suburban environments becomes more critical. Without a sense of what open spaces such as parks and gardens contribute, it is difficult to argue for their creation and maintenance: in the face of schools needing resources, roads and sewers needing maintenance, and people suffering at the hands of others, why should cities and counties spend scarce dollars planting trees and preserving parks? This book demonstrates the value of urban green. Focusing specifically on the role of vegetation and trees, the book shows the costs and benefits reaped from urban open spaces, from cooler temperatures to better quality ground water—and why it all matters. While this book is a work of science, it does not ignore the social component. The book looks at low-income areas that have poor vegetation, and shows how enhancing these areas through the planting of community gardens and trees can alleviate social ills.