Abstract
In forested headwater streams, various types of tree-derived materials such as leaf litter and woody debris are transported downstream through channel networks. Little is known about their characteristics and the mechanisms of their export, especially woody debris export. We review the roles of woody debris in streams from the aspects of geomorphology, ecology, erosion control engineering and water chemistry. We also demonstrate three processes, i.e., production, transport and retention, that affect woody debris export from forested catchments to provide needed information for water environment research.
