An important question for bioenergy is how a comprehensive use of forest fuel will influence the environment. Swedish scientists have contributed significantly to improving knowledge within this sector. This paper summarizes current research results on forest fuel and soil conditions, how ashes should be returned, forest fuel as a means to counteract the effects of nitrogen deposition, forest fuel and nature management. On the basis of current knowledge, it is concluded that it is possible to make use of large amounts of fuel from the forest with retained or perhaps even improved environmental status.