Review of current literature establishes that most authors believe that tree improvement expands production, although some point out drawbacks and alternatives. Both softwood and hardwood improvement programs have been analyzed. The authors used various models, economic assumptions, and standards of measurement, but available data were limited. Future models shouId attempt to be more eclectic.

More than half the world's population now lives in cities. Creating sustainable, healthy and aesthetic urban environments is therefore a major policy goal and research agenda. This comprehensive handbook provides a global overview of the state of the art and science of urban forestry. It describes the multiple roles and benefits of urban green areas in general and the specific role of trees, including for issues such as air quality, human well-being and stormwater management. It reviews the various stresses experienced by trees in cities and tolerance mechanisms, as well as cultural techniques for either pre-conditioning or alleviating stress after planting. It sets out sound planning, design, species selection, establishment and management of urban trees. It shows that close interactions with the local urban communities who benefit from trees are key to success. By drawing upon international state-of-art knowledge on arboriculture and urban forestry, the book provides a definitive overview of the field and is an essential reference text for students, researchers and practitioners.

Forest tree improvement has mainly been implemented to enhance the productivity of artificial forests. However, given the drastically changing global environment, improvement of various traits related to environmental adaptability is more essential than ever. This book focuses on genetic information, including trait heritability and the physiological mechanisms thereof, which facilitate tree improvement. Nineteen papers are included, reporting genetic approaches to improving various species, including conifers, broad-leaf trees, and bamboo. All of the papers in this book provide cutting-edge genetic information on tree genetics and suggest research directions for future tree improvement.

This handbook was designed as a reference tool for forest geneticists, tree breeders and other tree improvement personnel, as well as a textbook for university courses and short-courses at the graduate level in quantitative genetics. The chapters focus on the decision points faced by quantitative geneticists and breeders in designing programs and analyzing data. Beginning with a justification for the use of quantitative genetics in decision making in tree improvement programs, the book continues with a brief presentation of fundamental principles, followed by discussions and evaluations of mating designs and field test designs, the use of best linear predictors to estimate breeding values, the use of computer programs in the analysis of variance for genetic information, the deployment of genetically improved stock for capturing gains, the use of economic models for program justification, and the development of seed transfer guidelines.