Optimizing wetland restoration to improve water quality at a regional scale
Excessive phosphorus (P) export to aquatic ecosystems can lead to impairedwater quality. There is a growing interest amongwatershedmanagers in using restoredwetlands to retainP fromagricultural landscapes and improvewater quality.Wedevelop a novel framework for prioritizingwetland restoration at a regional scale. The framework uses an ecosystem servicemodel and anoptimization algorithm thatmaximizes P reduction for given levels of restoration cost. Applying our framework in the LakeChamplainBasin,wefind thatwetland restoration can reduce P export by 2.6% for a budget of $50Mand5.1% for a budget of $200M. Sensitivity analysis shows that usingfiner spatial resolution data forP sources results in twice the P reductionbenefits at a similar cost by capturinghot-spots on the landscape.We identify 890wetlands that occur inmore than 75%of all optimal scenarios and represent priorities for restoration.Most of thesewetlands are smaller than 7 hawith contributing area less than 100 ha and are locatedwithin 200mof streams.Our approachprovides a simple yet robust tool for targeting restoration efforts at regional scales and is readily adaptable toother restoration strategies.