Cooperative Fish and Wildlife Research Units Program: Pennsylvania
Education, Research and Technical Assistance for Managing Our Natural Resources

Accurate and robust approaches for quantifying regional reference conditions are critical to the management and restoration of freshwater resources. We review four common approaches to quantify regional reference conditions. We consider approaches that have been developed for streams, lakes, or wetlands and for either biological or chemical waterbody features. The four approaches we discuss are: multimetric, multivariate, landscape-context statistical modeling, and paleolimnology. We focus on the major steps in the decision-making process that lead to the most appropriate approach. Based on this synthesis, we argue that there is a need to: (1)more explicitly quantify the spatial scale of waterbody variation within and across regions; (2) develop and use predictive classification models in a more explicit fashion to more effectively model this local and regional variation; (3) consider additional metrics with a focus on lakes and wetland responses to both individual and multiple anthropogenic stressors; and (4) continue to develop quantitative approaches to explicitly account for uncertainties in regional reference condition predictions.