Water Resources Collections and Archives

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.