Tuolumne River Report - U.S. Fish and Wildlife Service

GEOMORPHIC AND RIPARIAN INVESTIGATIONSSan JoaquinRiver FlowTuolumneRiver FlowCONFLUENCETRANSECTSan JoaquinRiver FlowCHAPTER 3NFigure 3-35. Confluence vegetation transect location (RM 0.5), shownon 1993 aerial photograph (approximate scale: 1” = 700’).canopy, are mature valley oaks. On the historicfloodplain margin towards the bankfull channel, a20 ft tall, dense narrow-leaf willow thickettransitions into a mature box elder stand (Figure3-39). The narrow-leaf willow canopy is dense,with a short break before the open box eldercanopy. Another stand of narrow-leaf willow isgrowing on the evolving point bar near the lowflow water surface.This transect shows that pre-NDPP riparianvegetation established and matured on the historicfloodplains, while younger post-NDPP riparianvegetation is regenerating on post-NDPP floodplains,which are within the pre-NDPP bankfullchannel. These data suggest that regenerationcan occur at other reaches, but on a smaller scalewithin the historic bankfull channel, and perhapsonly at sites where channel migration allows thechannel to re-form a post-NDPP bankfull channel133