At present, roughly half of the world's population lives in urban centers. There are now more than 20 cities with a population of over 10 million inhabitants, compared to less than 5 about 50 years ago. This tendency toward urbanization is expected to continue, particularly in the developing world. A consequence of this growing trend is that millions of people are being exposed to harmful levels of urban air pollutants caused mainly by emissions from motor vehicles and from industrial and domestic activities involving the combustion of fossil fuels. The driving force for the design and implementation of emission control strate gies aimed at improving air quality has been the protection of the health of the population in urban centers. There are, however, other consequences of the pres ence of air pollutants besides the direct effect on human health. Reduced visibil ity, damage to monuments and buildings, and many other such consequences indirectly affect our quality of life. Another set of consequences involves damage to ecological systems. In fact, the nature of "photochemical smog" was first uncovered in the 1950s in connection with observations of its harmful effects on crops and plants in the vicinity of Los Angeles.

At present, roughly half of the world's population lives in urban centers. There are now more than 20 cities with a population of over 10 million inhabitants, compared to less than 5 about 50 years ago. This tendency toward urbanization is expected to continue, particularly in the developing world. A consequence of this growing trend is that millions of people are being exposed to harmful levels of urban air pollutants caused mainly by emissions from motor vehicles and from industrial and domestic activities involving the combustion of fossil fuels. The driving force for the design and implementation of emission control strate gies aimed at improving air quality has been the protection of the health of the population in urban centers. There are, however, other consequences of the pres ence of air pollutants besides the direct effect on human health. Reduced visibil ity, damage to monuments and buildings, and many other such consequences indirectly affect our quality of life. Another set of consequences involves damage to ecological systems. In fact, the nature of "photochemical smog" was first uncovered in the 1950s in connection with observations of its harmful effects on crops and plants in the vicinity of Los Angeles.

Proceedings of the Twenty-Second NATO/CCMS International Technical Meeting held in Clermont-Ferrand, France, June 2-6, 1997

At present, roughly half of the world's population lives in urban centers. There are now more than 20 cities with a population of over 10 million inhabitants, compared to less than 5 about 50 years ago. This tendency toward urbanization is expected to continue, particularly in the developing world. A consequence of this growing trend is that millions of people are being exposed to harmful levels of urban air pollutants caused mainly by emissions from motor vehicles and from industrial and domestic activities involving the combustion of fossil fuels. The driving force for the design and implementation of emission control strate gies aimed at improving air quality has been the protection of the health of the population in urban centers. There are, however, other consequences of the pres ence of air pollutants besides the direct effect on human health. Reduced visibil ity, damage to monuments and buildings, and many other such consequences indirectly affect our quality of life. Another set of consequences involves damage to ecological systems. In fact, the nature of "photochemical smog" was first uncovered in the 1950s in connection with observations of its harmful effects on crops and plants in the vicinity of Los Angeles.

This book focuses on urban "green infrastructure" – the interconnected web of vegetated spaces like street trees, parks and peri-urban forests that provide essential ecosystem services in cities. The green infrastructure approach embodies the idea that these services, such as storm-water runoff control, pollutant filtration and amenities for outdoor recreation, are just as vital for a modern city as those provided by any other type of infrastructure. Ensuring that these ecosystem services are indeed delivered in an equitable and sustainable way requires knowledge of the physical attributes of trees and urban green spaces, tools for coping with the complex social and cultural dynamics, and an understanding of how these factors can be integrated in better governance practices. By conveying the findings and recommendations of COST Action FP1204 GreenInUrbs, this volume summarizes the collaborative efforts of researchers and practitioners from across Europe to address these challenges.

“Far-ranging and deeply researched, Urban Forests reveals the beauty and significance of the trees around us.” —Elizabeth Kolbert, Pulitzer Prize-winning author of The Sixth Extinction “Jonnes extols the many contributions that trees make to city life and celebrates the men and women who stood up for America’s city trees over the past two centuries. . . . An authoritative account.” —Gerard Helferich, The Wall Street Journal “We all know that trees can make streets look prettier. But in her new book Urban Forests, Jill Jonnes explains how they make them safer as well.” —Sara Begley, Time Magazine A celebration of urban trees and the Americans—presidents, plant explorers, visionaries, citizen activists, scientists, nurserymen, and tree nerds—whose arboreal passions have shaped and ornamented the nation’s cities, from Jefferson’s day to the present As nature’s largest and longest-lived creations, trees play an extraordinarily important role in our cities; they are living landmarks that define space, cool the air, soothe our psyches, and connect us to nature and our past. Today, four-fifths of Americans live in or near urban areas, surrounded by millions of trees of hundreds of different species. Despite their ubiquity and familiarity, most of us take trees for granted and know little of their fascinating natural history or remarkable civic virtues. Jill Jonnes’s Urban Forests tells the captivating stories of the founding mothers and fathers of urban forestry, in addition to those arboreal advocates presently using the latest technologies to illuminate the value of trees to public health and to our urban infrastructure. The book examines such questions as the character of American urban forests and the effect that tree-rich landscaping might have on commerce, crime, and human well-being. For amateur botanists, urbanists, environmentalists, and policymakers, Urban Forests will be a revelation of one of the greatest, most productive, and most beautiful of our natural resources.