ABSTRACT
The extreme variability in riparian systems, not only between streams but between reaches of the same stream, complicates description and analysis. Heterogeneity is inherent in riparian vegetation, especially in montane areas where elevation, exposure, substrate conditions, and gradient can change significantly in a short distance. Thus, different stream reaches may respond differently to changes in streamflow, complicating impact prediction. Because the impacts are difficult to define, mitigation is speculative. Mitigation for a particular resource often creates an impact on other resources. Pacific Gas and Electric Company is restoring riparian vegetation on Lost Canyon Creek in the western Sierra Nevada of California. The area is a boulder-strewn floodplain within a granitic streambed, but contains sufficient sediment fines to attempt plantings in localized areas. Riparian vegetation on headwater streams is often distributed in patches, presenting engineering difficulties with traditional irrigation schemes, such as pipeline, dripline, sprinkler, or flooding.
