Distribution of coarse woody debris in a mountain stream, western Cascade Range, Oregon

The distribution of coarse woody debris in a fifth-order Cascade Range (Oregon) stream system was examined froma geomorphic point of view. The number, volume, location, orientation, decay class, and pool formation roles of coarsewoody debris were investigated. The processes of coarse woody debris production, transport, and storage, which varywith channel and valley floor geomorphology, are responsible for the pattern of coarse woody debris distribution onvalley floors. Channel width and sinuosity are the main factors that control production, storage sites, and hydrologiceffects of coarse woody debris. The amount of coarse woody debris and the number of pool-forming pieces arerelatively high in wide, sinuous reaches, where a complex structure of floodplains and riparian forests developsin association with a braided channel pattern. These relations are transferable to other systems with similar relationsof coarse woody debris piece length to channel width.