A Note on the Robustness of Aggregate Ecosystem Service Values

There is increased interest in estimating the value of ecosystem services at the global scale. The usefulness of these global valuation exercises that combine hundreds of individual value estimates depend on the robustness of the results. This commentary raises a potential issue with these aggregate estimates: the fragility to a few influential outliers. Using recent research as an illustration, I demonstrate how these synthesis studies can mask how a few specific value estimates are responsible for a large portion of ecosystem service value. These findings suggest that additional caution should be used in interpreting aggregate value estimates, that researchers should check aggregate estimates for the presence of influential outliers, and specific ecosystem service research areas that should be pursued.