Forest soils have characteristic properties that set them apart from the usual types of soils used for growing crops. Often rocky, of poor quality, and in mountainous terrain, forest soils are nevertheless the foundation of the entire forest ecosystem, supporting a diverse assemblage of plants and animals. They are often fragile soils, easily subject to erosion by road building or logging operation. A proper understanding of forest soils is an essential component of understanding forest ecology and maintaining the diversity and productivity of forested land. This new edition emphasizes the ecological aspects of forest soils. It is global in its scope, discussing soil types ranging from the tropical rainforest soils of Latin America to the boreal forest soils of Siberia. Separate chapters discuss the physical, chemical, and biological aspects of forest soils, with additional chapters on soil organic matter, roots, and biogeochemistry. It highlights the site specific factors that are important in each case and discusses practical management aspects including: nutrition management, thinning, site preparation techniques, soils for nursery and seed orchard operation, problem soils, atmospheric deposition of nutrients, soil acidity, and techniques for sustaining and improving long term soil productivity.