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Table 1 Definition of components of the primary systematic review question

From: How effective are reedbeds, ponds, restored and constructed wetlands at retaining nitrogen, phosphorus and suspended sediment from agricultural pollution in England?

Subject (Population) Intervention Comparator Outcome
Water bodies receiving: Wetland: • Input vs output concentration to  wetland 1°: Percentage change in water quality measure
• Nitrogen (N) • Constructed/treatment • No wetland vs with wetland present 2°: Change in other parameters, including biodiversity measures and greenhouse gas emission; are there any synergies/trade-offs, e.g. flood risk?
• Phosphorus (P) • Restored • Before wetland vs with wetland present  
• Suspended solids/sediment (SS) • Reedbeds   
  • Ponds