A multi-Criteria Wetland Suitability Index for Restoration across Ontario’s Mixedwood Plains

Abstract

Significant wetland loss (~72%; 1.4 million hectares) in the Province of Ontario, Canada, has resulted in damage to important ecosystem services that mitigate the effects of global change. In response, major agencies have set goals to halt this loss and work to restore wetlands to varying degrees of function and area. To aid those agencies, this study was guided by four research questions: (i) Which physical and ecological landscape criteria represent high suitability for wetland reconstruction? (ii) Of common wetland suitability metrics, which are most important? (iii) Can a multi-criteria wetland suitability index (WSI) effectively locate high and low wetland suitability across the Ontario Mixedwood Plains Ecozone? (iv) How do best sites from the WSI compare and contrast to both inventories of presettlement wetlands and current existing wetlands? The WSI was created based on seven criteria, normalized from 0 (low suitability) to 10 (high suitability), and illustrated through a weighted composite raster. Using an Analytical Hierarchy Process (AHP) and importance determined from a scoping review of relevant literature, soil drainage had the greatest meaning and weight within the WSI (48.2%). The Getis-Ord Gi* index charted statistically significant “hot spots” and “cold spots” of wetland suitability. Last, the overlay analysis revealed greater similarity between high suitability sites and presettlement wetlands supporting the severity of historic wetland cannibalization. In sum, this transferable modeling approach to regional wetland restoration provides a prioritization tool for improving ecological connectivity, services, and resilience.