Taxonomy and classification of the Salicaceae are addressed in an authoritative manner, with descriptions of all important individual species, but recognizing the differences in philosophy that still exist in these topics. Natural ecosystems are described. Genetic resources of poplars and willows are covered comprehensively, including selection, tree improvement and conservation, as well as the latest developments in genomics. Cultivation of poplars in plantations for industrial uses was the core of previous volumes and continues to be given prominent treatment, with information also on willow cultivation. A major 21st century topic included is the environmental applications of poplars and willows in phytoremediation, rehabilitation of landscapes and for carbon sequestration, biodiversity and urban amenity, among other uses (McCutcheon and Schnoor, 2003). The most important diseases of poplars and willows are described, as well as strategies for their control. Insects and other animal pests of poplars and willows are treated similarly. Wood properties and utilization of poplars and willows for traditional, as well as emerging, new products are presented. Markets, trends and outlook for wood products worldwide are analysed, considering poplars in relation to tree species in general. The benefits of poplars and willows for sustainable land use and rural livelihoods, including agroforestry, food security, poverty alleviation and shelter, particularly in developing countries, are highlighted.