Integrating Ecology and Economics for Restoration: Using Ecological Indicators in Valuation of Ecosystem Services

Because it can uniquely furnish insights into nonuse values for ecosystem services, survey-based Stated Preference (SP) valuation is widely used to estimate the benefits of ecological restoration. SP surveys ask respondents to select among restoration options yielding different ecological outcomes. This review examines the representation of ecological outcomes in SP studies seeking to quantify values for restoration of aquatic ecosystems. To promote the validity of ecological indicators used in SP valuation, we identified four standards: indicators should be measurable, interpretable, applicable, and comprehensive. We reviewed recent SP studies estimating the value of aquatic ecosystem services to assess whether ecological indicators in current use had these desirable properties. More than half of the 54 indicators reviewed were measurable, meaning referable to potentially precise quantification. About one third were interpretable, i.e., presented in a way that facilitates understanding the effects of restoration. About three quarters of the indicators were applicable; SP valuation practitioners typically consult with natural scientists to ensure that indicators represent the effect of stressors on ecological systems, and with focus groups to ensure that indicators have a connection with ecosystem services that contribute to public well-being. While most of the SP studies employed diverse and potentially comprehensive indicators that could capture direct and indirect effects of restoration, and six of twenty studies used indicators that met all standards, shortcomings in the indicators were common. These problems can be rectified with attention to how natural scientists measure change, and to relationships between restoration outcomes and characteristics of fully-restored reference ecosystems