Using Meta-Analysis to Develop Evidence-Based Recovery

To develop effective marshland restoration programs we need to understand how different approaches affect different aspects of the marshland. Abt was part of a team that analyzed the effect of sediment addition to coastal wetlands in the northern Gulf of Mexico. Broadly, mean values for restored sites reached reference site conditions within 30 years following restoration. At a more granular level, vegetation cover was 50 percent lower at restored sites during the first 5 years of restoration, but aboveground biomass was 25 percent higher, while biomass and soil organic matter were 44 percent to 92 percent lower during the first 15 years of restoration. Because recovery rates vary for different elements of marshland, the appropriate restoration response—and performance measures—will need to take those variables into account.