We evaluated the survival of planted riparian vegetation within a restored reach of Miller Creek in Marin County, CA, and analyzed survey results to identify factors affecting tree survival. We surveyed three plots approximately 100 feet square within the restored reach. Of the three plots surveyed, the most downstream plot has the highest plant survival rates. The survival rates of tree species in the three plots, from upstream to downstream, were 35%, 43%, and 88%, respectively. Despite early irrigation, many of the trees planted in the two upstream plots have died, but both plots are slowly developing vegetative complexity, with volunteer shrubs filling in gaps and providing protection for new tree saplings. Our analysis of tree species survival by plant elevation, aspect, susceptibility to inundation, and soil types, indicated three likely important factors: location along the creek, aspect, and local geology and soil conditions. In future stream restoration projects, it may be cost-efficient to study the area’s soils, underlying geology, and seasonal water table elevations to maximize plant survival rates. Alternately, a planting strategy that mimics natural succession would require more planning but might be more effective.

Miller creek is located in Marin County, California, and runs east from Big Rock Ridge through the Laws Gallinas Valley and into the San Pablo Bay. The Miller Creek watershed has been grazed continuously since the 1800s, and the creek has experienced sever widening and down cutting as a result. The miller Creek restoration Project, located in the Lucas Valley Estates subdivision and designed and built from 1979 to 1989, employed a multi-stage channel approach to restore and protect a riparian corridor through the subdivision, and prevent further lateral migration of the creek bed. In this study, the authors compared surveyed cross sections to drawings of the original channel conditions and the designed channel conditions, to determine channel response to the restoration activities. They also conducted a qualitative evaluation of the habitat quality within the project reach, and of vegetation establishment. They found that within the floodplain, the stream is evolving in a natural manner, with erosion of some banks and deposition on the flood plain. In some stretches, however, the stream bed is flat, shallow, and exposed, with no morphological complexity and poor habitat value, These conditions may be the result of poor survival rates of planted vegetation and naturally recruited seedlings.