The forests of the world represent a vast potential source of raw material containing energy. This energy source is completely renewable and in principle is almost neutral with regard to balances of greenhouse gases which are implicated in global climate change. In the boreal and temperate forest regions at least, the potential remains largely untapped, but developments are taking place which are likely to increase the use of biomass for energy from plantations and naturally-regenerated forests. Bioenergy, as one of the renewable energy forms, is receiving greater emphasis in many countries as a means of improving carbon balances and mitigating global climate change. In other parts of the world, the procurement and use of woodfuel are very important in the lives of ordinary people. Unless management of the source of bioenergy in plantations and naturally regenerated forests is carried out on a truly sustainable basis, these developments could bring environmental and socio-economic problems. The editors of this book undertook the task of producing it in the hope that we could thereby help to ensure the sustainability of bioenergy production from the forest. We did not intend to give detailed answers for every situation. Rather the book provides guidelines to the general principles that must be considered. It goes further by showing how a truly sustainable bioenergy system integrates and even transcends the totality of its ecological, silvicultural, technical, economic, social and institutional components. We have tried to suggest the kinds of practices that can follow from general principles to promote sustainability. The scope of the book extends to naturally-regenerated forests and plantations from which bioenergy is only one of several products. Others may include timber, wood fiber for pulp or chemicals, water or a static role in environmental protection, recreation or shelter. There is less emphasis on plantations of trees or other crops such as switchgrass or short-rotation willow coppice grown expressly for energy production. The eco-geographic focus is on the boreal and temperate regions, particularly in countries of the Organization for Economic Co-operation and Development (OECD), recognizing also the vital importance of woodfuel in other parts of the world, includingtropical and sub-tropical regions.