Improved permitting standards, requirements, monitoring and enforcement of those standards is necessary to improve wetland restoration outcomes. Existing program regulations and guidelines generally restrict monitoring times to assess wetland restoration over 3-5 years. For the vast majority of restoration sites, this timeframe is wholly inadequate, particularly for wetland types that develop over a long period of time, such forested wetlands, bogs and fens. Even with wetlands that can develop within a 3-5 year period, weather, hydrologic or other changes may mean that in a particular case a much longer time may be required. In practice, wetland restoration projects can have a finite endpoint, but ecosystem development does not. The restoration activities can be judged as completed or not, but the performance of a wetland restoration site will vary in perpetuity, as new challenges arise.
Project proponents may need a judgment of “in compliance” in order to terminate work, and most will want a judgment of “success” to showcase their projects. Compliance can be judged objectively if there are both clear goals for performance and a priori standards for the level of performance. A wetland can support native species at the numbers prescribed at the age of 3 years, but the native species won’t persist if the site is gradually shifting toward dominance by a monotype-dominant invasive plant (i.e., one that displaces other species) such as hybrid cattails (Typha x glauca) or reed canary grass (Phalaris arundinacea) (Frieswyk, Johnson & Zedler, 2008). A judgment of “success” at age 3 is not a science-based judgment. A number of wetland restoration experts support longer timeframes and/or focusing on one or two objectives and measuring progress rather than attempting to establish long-lived plants or peat-rich soils in a relatively short period of time.
Short term monitoring data can describe initial conditions and suggest a site’s potential to sustain itself. It is recommended that practitioners measure progress using quantifiable ecological performance standards (e.g., Indices of Biotic Integrity, Floristic Quality based on Conservatism Indices, Wetland Indicator Status). It is important that terminology be clear and consistent. Baseline assessments are needed for both the restored site upon project completion and the reference site(s) at the same time. These should be developed using multiple indicators of structure and function that relate to the specific project objectives. Monitoring locations need to be representative of the entire wetland restoration project. Monitoring site selection should ensure that the data collected will provide an assessment of the entire project.
Useful Publications & Resources
- Wetland Assessment: Measuring the Quality of the Nation's Wetlands (Stetson, 2008)
- Common Questions: Wetland Assessment (Kusler, 2006)
- Common Questions: Definition of the Terms Wetland "Function" and "Value" (Kusler, 2006)
- Recommendation of Reconciling Wetlands Assessment Techniques (Kusler, 2006)
- Wetland Assessment for Regulatory Purposes: Report Series (Kusler, 2004)
- Identifying and characterizing dominant plants as an indicator of community condition (Frieswyk, Johnston & Zedler, 2007)