Southern Canada’s crisis ecoregions: identifying the most significant and threatened places for biodiversity conservation

Abstract Identifying and protecting key areas for biodiversity is a cornerstone of effective nature conservation. This conservation assessment analyzes 77 ecoregions across the southern, settled part of Canada to identify priorities for conservation action. Our analysis included 34 measures of biodiversity, threat and conservation response. We categorized all ecoregions based on their overall biodiversity and threat scores. This categorization identified nine “crisis ecoregions.” These ecoregions have higher biodiversity and threat scores compared to other ecoregions in the study area. These ecoregions represent less than 5% of Canadian lands and inland waters but provide habitat for over 60% of Canada’s species at risk. Twenty-one ecoregions have higher biodiversity but lower threat scores. Primarily distributed in the more intact portions of the study area, these ecoregions generally have lower biodiversity scores for species diversity, but score very high for intactness, habitat diversity and congregatory species. This assessment can help to contextualize existing and proposed conservation actions by highlighting key biodiversity, threat and conservation attributes of ecoregions across southern Canada. Our assessment can be used to focus efforts on new protected areas, species at risk recovery, capacity building and ecological monitoring. The results of the conservation assessment can be applied to set and track progress toward national, regional and organizational conservation goals, including post-2020 biodiversity targets. Regular reanalysis of the ecoregions to track their trends in biodiversity, threat and conservation responses will support monitoring the effectiveness of conservation programs and highlight ecoregions where continued focus is most needed to conserve Canada’s biodiversity.