This text provides a synthesis by scientists in the study of the major physiological and environmental factors regulating cold hardiness of conifer tree species. This reference explains contemporary understanding of conifer cold hardiness ranging from the gene to the globe and from the highly applied to the very basic. Topics addressed encompass cold hardiness from the perspectives of ecology, ecophysiology, acclimation and deacclimation, seedling production and reforestation, the impacts of biotic and abiotic factors, and methods for studying and analyzing cold hardiness. The content is relevant to geneticists, ecologists, stress physiologists, environmental and global change scientists, pathologists, advanced nursery and silvicultural practitioners, and graduate students involved in plant biology, plant physiology, horticulture and forestry with an interest in cold hardiness.