We developed tools to assess the overall condition of wetlands, consistent with California’s Wetland and Riparian Area Monitoring Plan, which calls for map-based landscape inventories, rapid field assessment, and intensive quantitative field measures. The California Rapid Assessment Method (CRAM) is a field-based, cost-effective, and scientifically defensible tool for monitoring wetlands. It is structured to guide the user through the wetland’s structure from landscape level to site-specific plant community composition. We validated three CRAM modules by examining correlations between CRAM data and intensive field measures, including macroinvertebrate and algae indices of biotic integrity (IBIs), water quality, vegetation surveys, and rare branchiopod surveys. Depressional, Slope, and Vernal Pool CRAM modules were validated. For depressional wetlands we leveraged data collected in Southern California and the Bay Area (15 sites each), and also collected new data in 2014 with consistent methods at 15 sites in Northern California. In 2015, 40 slope wetland sites across California were assessed using CRAM. Existing vegetation data collected by the USFS or NPS or data collected following their methods was used. Thirty vernal pool sites were assessed in 2016 with CRAM, and intensive vegetation and aquatic macroinvertebrate survey data was compiled from partners who monitored those pools.
Results/Conclusions
Depressional CRAM data was significantly correlated with the macroinvertebrate IBI (ρ = 0.42, p = 0.0036) and the algae IBI (ρ = 0.49, p = 0.0005). Slope CRAM results show significant correlations between CRAM Index and Attribute scores and vegetation metrics such as percent native cover (ρ = 0.76, p = 0.000), and the Ratliff Vegetation Score (ρ = 0.62, p = 0.000). Vernal Pool CRAM was correlated with vegetation metrics such as vernal pool endemic species richness, and with special status large branchiopod population measures. Results indicate that CRAM is sensitive to some of the same factors that affect macroinvertebrate, algae, and vegetation communities, which validates its effectiveness. CRAM is a powerful tool for assessing the success of wetland restoration projects. It has been used at multiple projects to track change in condition through the restoration trajectory. Initially, the overall condition may decrease after grading and the disturbance it causes. Over time as the project matures and native plantings become established, the condition improves with maintenance and adaptive management. We have developed a robust training program for CRAM practitioners and higher level managers.