The functional role of large wood in streams has been the subject
of numerous studies over the last 50 years. Much of the early
research concerned the influence of large concentrations of wood
on fish migration and oxygen depletion associated with decomposition
where accumulations are substantial. In many cases, such information
was used to justify the removal of large wood from streams in
the Pacific Northwest, and these extractive practices may have
actually confounded attempts to understand the ecological role
of large wood in fluvial systems.
Subsequent
research suggested that the amount of spawning area that was
isolated by debris dams was not great, and concomitantly,
the ecological role of large wood has become increasingly
apparent. For instance, large wood controls channel morphology
and sediment and water routing in the channel, and it provides
habitat structure and complexity for numerous aquatic and
terrestrial organisms. Periodic variations in the influx of
sediment and large wood contribute to habitat heterogeneity
that is reflected in diverse aquatic communities.
The purpose of this study is to document the geomorphic function
of large wood in headwater streams. Of particular interest
is how the physical obstruction created by large wood in headwater
streams influences sediment 
storage,
and how the functional role of large wood varies with input
process and stream size. This study is directly integrated
with field investigations for the Large Wood Recruitment
and Redistribution study.
For additional information about this completed research study see
the 2001
CFER Annual Report. (1.1 MB)
