Staszak, L.A. and Armitage, A.R., 2013. Evaluating salt marsh restoration success with an index of ecosystem integrity.
In concept, ecological restoration will improve ecosystem characteristics of degraded habitats, but in practice, restoration success assessments typically target vegetation communities. We sought to determine if estuarine emergent marsh restoration projects (Galveston Bay, Texas) that had successfully achieved permit-mandated plant coverage were comparable to reference sites at an ecosystem level. We used a Rapid Assessment Method developed specifically for this habitat (Galv-RAM) to compare restored (ages 5–15 y) and reference marshes. Thirteen biotic and abiotic characteristics were used to calculate an ecosystem index score, whereby a pristine habitat would score 100%. The average Galv-RAM ecosystem index score for reference marshes (81%) was typical for urbanized estuaries. Restored marshes scored 75%, indicating that they were relatively well developed, although there was substantial variability in ecosystem index scores among sites. Discriminant function analysis revealed that reference sites had more benthic epifauna (periwinkles, fiddler crabs); epifauna were virtually absent from restored sites. Overall, Galv-RAM scores did not vary with restored marsh age, but some individual features changed over time: older restored sites tended to have higher plant diversity and belowground plant biomass than younger restored sites. The ultimate goal of coastal wetland restoration is to improve the integrity of the regional wetland landscape by augmenting many different ecosystem functions. Therefore, although not all measured variables scored optimally in all restored sites, each of the sites had relatively high ecological value and contributed to the integrity of a larger scale matrix of wetland habitat.