Development of Vegetation and Aquatic Habitat in Restored Riparian Sites of California’s North Coast Rangela

Lennox, M. S., et al., 2011. Restoration Ecology

Original research (primary data)
View External Publication Link


The preponderance of short-term objectives and lack of systematic monitoring of restoration projects limits opportunities to learn from past experience and improve future restoration efforts. We conducted a retrospective, cross-sectional survey of 89 riparian revegetation sites and 13 nonrestored sites. We evaluated 36 restoration metrics at each site and used project age (0-39 years) to quantify plant community and aquatic habitat trajectories with a maximum likelihood model selection approach to compare linear and polynomial relationships. We found significant correlations with project age for 16 of 21 riparian vegetation, and 11 of 15 aquatic habitat attributes. Our results indicated improvements in multiple ecosystem services and watershed functions such as diversity, sedimentation, carbon sequestration, and available habitat. Ten riparian vegetation metrics, including native tree and exotic shrub density, increased nonlinearly with project age, while litter and native shrub density increased linearly. Species richness and cover of annual plants declined over time. Improvements in aquatic habitat metrics, such as increasing pool depth and decreasing bankfull width-to-depth ratio, indicated potentially improved anadromous fish habitats at restored sites. We hypothesize that certain instream metrics did not improve because of spatial and/or temporal limitations of riparian vegetation to affect aquatic habitat. Restoration managers should be prepared to maintain or enhance understory diversity by controlling exotic shrubs or planting shade-tolerant native species as much as 10 years after revegetation.

Case studies

Basic information

  • Case ID: INT-139-1
  • Intervention type: Restoration
  • Intervention description:

    focused on establishing Salix species to “jump start” recovery of riparian forests; The methods utilized were often implemented as combinations of practices including tree or shrub planting with dormant willow posts or container plants (Johnson 2003), biotechnical bank stabilization (Johnson 2003; Flosi et al. 2004), and passive restoration (Kauffman et al. 1997) using large herbivore management (e.g., removal, reduced stocking rate, or exclusionary fencing for livestock and/or deer).

  • Landscape/sea scape ecosystem management: Yes
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Reduced water quality  Positive proxies of water quality: stream bank stability, stream channel morphology
  • Approach implemented in the field: Yes
  • Specific location:

    102 sites in Marin, Mendocino, and Sonoma Counties [California]

  • Country: United States of America
  • Habitat/Biome type: Streams, rivers, riparian |
  • Issue specific term: Not applicable


  • Notes on intervention effectivness: effectiveness determined by assessing change in outcome measures over time (no control) --> although they say they also assess non-restored sites that could have acted as controls, they do not present results in comparison to these sites "the changes we found in stream channel morphology and streambank stability were expected and should result in improved water quality with less chronic sediment delivery to streams from restored sites"
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: Yes
  • Impacts for the ecosystem: Mixed
  • Ecosystem measures: re-establishment of native plant species "Site-specific riparian revegetation strategies were successful in maintaining native tree and shrub density, cover, and richness over multiple decades." but "Annual species richness decreased linearly as project age increased" persistence of exotics "The increase in exotic shrub density over time was unin- tended and undesirable."
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: No
  • Experimental evalution done: Not applicable
  • Non-experimental evalution done: Empirical case study
  • Study is systematic: