A method for Evaluating Outcomes of Restoration When No Reference Sites Exist
Brewer, J. S. and Menzel, T. (2009), A Method for Evaluating Outcomes of Restoration When No Reference Sites Exist. Restoration Ecology, 17: 4–11. doi: 10.1111/j.1526-100X.2008.00456.x
The authors develop a method to create hypothetical reference assemblages (for plants or animals) using regional species lists with habitat and location information. Their case study was the open oak woodland in Northern Mississippi. The approach uses community similarity-based indicator scores for every species in the community to construct plant or animal assemblages for reference sites and allow practitioners a method of evaluating success of the restoration project.
The pluses. This method would be especially useful for hypothesizing what the structural components of a restored rare habitat look like where reference sites do not exist. The method also may be more effective than using species richness or evenness to evaluate success because the community similarity-based indicator provides more information about compositional changes relevant to conservation and restoration. For instance, the method can predict the likelihood of a species occurring in a particular habitat, even if regional surveys do not list it as occurring in that habitat.
The minuses. The method only addresses structural components of a reference site, perhaps less important than the process-based aspects of a restoration project (Palmer 2009). The complexity of the formula may also be a deterrent for the average restoration practitioner to adopt this method to evaluate restoration success. In addition, this method relies on the existence of a regional plant list with species, habitat, and location information. In a place like California, with many habitat types in a regional area, a regional list may not be an appropriate starting point. Lastly, the method relies on existing plant species habitat ranges and does not address futuristic species habitat ranges. Understanding what is likely to live in this habitat type in the future (considering climate change) is essential when developing a hypothetical reference site.