Our assessment supports conservation in Canada by providing a systematic framework to categorize ecoregions based on biodiversity, threat and conservation response. Although ecoregions with higher biodiversity and threat levels are generally known for southern Canada, and some have been identified in global and North American assessments (Olson and Dinerstein 2002; Ricketts et al. 1999), our analysis provides the first framework that assesses all ecoregions in southern Canada using a standardized approach.
Canada’s nine crisis ecoregions have higher biodiversity and threats scores compared to other ecoregions in southern Canada and will be particularly challenging to manage for conservation. Five of the nine crisis ecoregions have less than 5% of their lands and inland waters in protected areas and the high level of threat represents the many competing land uses including agriculture, urban areas and resource development. Some of the existing protected areas within the crisis ecoregions may be too small or fragmented to maintain the biodiversity values for which they were established (e.g. Browne and Hecnar 2007). Many protected areas in the crisis ecoregions will also require active management and restoration to maintain their biodiversity and mitigate threats associated with small, fragmented nature reserves.
Results from our analysis can be used to help identify key regions to build clusters of effective habitat (Wiersma and Simonson 2010; Wiersma et al. 2004). Traditional government led protected areas can play and important role in these ecoregions but will need to be supported by Privately Protected Areas and Other Effective Area-based Conservation Measures, including conservation management agreements with landowners to maintain and restore biodiversity.
Only one of the nine crisis ecoregion that we identify, Northern Continental Divide, has over 17% of its lands and inland waters in protected and conserved areas. However, much of this protection is focussed in higher elevations and connectivity in the valley lands is highly restricted and under threat. The Northern Continental Divide and six of the other crisis ecoregions are located along Canada’s southern border with the U.S., and conservation of species, ecosystems and connectivity will require transboundary conservation.
The analysis also identifies ecoregions in southern Canada that have higher biodiversity values but lower overall threat. Because these ecoregions often have a higher proportion of public lands and protected areas, many of them offer an opportunity to protect large and intact conservation networks. Some of these ecoregions include the 23% of the Earth’s terrestrial surface that has not been significantly modified by the direct effects of human activities (Watson et al. 2018), including the Central Laurentians and Columbia Mountains and Highlands ecoregions. Protecting 17% has already been achieved in several higher biodiversity and lower threat ecoregions. In other ecoregions this can be accomplished through private and public land protection and Indigenous Protected and Conserved Areas.
The results of our assessment provide conservation practitioners with a framework to better contextualize conservation projects and to track progress toward national, regional and organizational conservation goals. It can provide a foundation to explore the feasibility, constraints, and opportunities to set and strive toward ecoregional-based conservation objectives and ensure that progress in meeting national targets occurs not just in the ecoregions where conservation can happen, but in the ecoregions where conservation must happen to protect Canadian biodiversity.
This assessment also provides a framework that could be applied to update Canada’s 2010 Ecosystem Status and Trends Reporting (Federal Provincial and Territorial Governments of Canada 2010). The data and results are also complementary to existing national-scale monitoring initiatives including Canadian Environmental Sustainability Indicators, such as Canada’s conserved areas (ECCC 2018b) and the World Wildlife Fund Living Planet Index for Canada (WWF Canada 2017) on national wildlife declines. The results support the identification of “shared priority places” under Canada’s 2019–2022 Federal Sustainable Development Strategy (ECCC 2018a), and can help guide Canada’s post-2020 biodiversity framework, including targets for the 2021–2030 UN Decade of Ecological Restoration.
In addition to monitoring and reporting at the ecoregional scale, the criteria used in the assessment could be used to develop new indicators for monitoring conservation in Canada. In particular, a conservation assessment can support Canada in reporting on key elements of Aichi Target 11, including connectivity, representation and ‘areas of particular importance for biodiversity, and in developing post-2020 targets that focus on qualitative conservation measures (Lemieux et al. 2019).
The lens of ecoregions can help identify local actions that will contribute to biodiversity conservation from a Canadian context. Regional governments, land trusts and other conservation organizations can use this assessment to help coordinate conservation efforts in priority areas and demonstrate that resources are being directed to the areas that are of greatest importance and urgency for biodiversity conservation in Canada.
This assessment builds on past ecoregional assessments in southern Canada (e.g. Gratton 2010) and studies that have identified geographical gaps in conservation nationally (Iacobelli et al. 2006; Wiersma et al. 2009) and provincially (Freemark et al. 2006; Gauthier and Wiken 2003). The results can also support the current initiative to identify Key Biodiversity Areas (KBAs) in Canada (IUCN 2016). Ecoregions that have the highest score for species of global conservation concern and nationally endemic species have high probability of containing sites that could qualify under the KBA criterion for threatened species and geographically restricted biodiversity. These ecoregions include Appalachians, Fundy Coast and Eastern Vancouver Island. Ecoregions that have large habitat blocks, or large areas of natural cover compared could qualify as Key Biodiversity Areas the criterion for ecological integrity.
There are important elements of biodiversity that were not included in this study because they lack spatial information, occur at smaller geographical scales or have not yet been identified. Systematic biological surveys have not been conducted in many regions of the study area. The scoring system developed for this assessment was designed to be flexible and accommodate new measures and updated data. Additional measures that could be incorporated in the assessment as better data becomes available includes concentrations of migratory mammals or insects, range maps for additional species, richness of freshwater biodiversity and intact faunal assemblages for groups other than mammals. Information on nationally and globally rare or endemic vegetation communities does not yet exist because Canada’s national vegetation classification system is incomplete, and vegetation communities are not tracked and ranked by many Conservation Data Centres. Better information on the distribution and status of vegetation communities, including current initiatives to identify Red List ecosystems (Ferrer-Paris et al. 2018; Rodríguez et al. 2015), would help support future iterations of this assessment.
Integration of additional socio-economic information into the analysis, such as forecasts on population trends, land value, and household income, could help to refine levels of risk and identify conservation opportunities. For example, Ontario’s population is projected to increase by 38% by 2046, with much of that growth focussed around the urban areas in the Lake Erie Lowland ecoregion (Ontario Ministry of Finance 2019).
Additional climate change models could be also considered to identify ecoregions most likely to continue to experience rapid changes in temperature, precipitation and other variables. Forecasting and mapping these potential future threats would help to identify those ecoregions that have the highest probability of experiencing future change and are in need of conservation action.
Our connectivity analysis did not incorporate models of potential species movements and habitat shifts due to climate change (e.g. Lawler et al. 2013). As additional information on projected species’ range shifts, climate stability and potential climate refugia (Iwamura et al. 2010) become available and the certainty of these predictions increases, such data could help to refine the scoring of ecoregions.
Expanding our assessment to all of Canada would provide a more complete picture of biodiversity, threats and conservation needs, and national context for conservation actions. This assessment examines Canada’s southern landscapes that have already been significantly altered and where conservation and often restoration are urgently needed. While parts of Canada’s north are under pressure from industrial activities and climate change is rapidly altering the ecology of this region, there remains a globally significant opportunity to work with Indigenous Peoples to conserve large, intact landscapes. Although biodiversity data for some criteria is poorly documented in the north, there is information that would support the initial identification of important sites and networks. For example, the Athabasca sand dunes and the Beringia region of the Yukon are known to have high concentrations of at-risk, endemic and globally rare species.
Assessing the relative importance of biodiversity conservation over large scales is complex and depends on the measures and criteria that are applied (Brooks et al. 2006). Alternative approaches to our analysis could combine top scores based only on species measures or stratify the final scores based on ecozones. Applying the scoring that we developed to smaller scales based on ecological boundaries or a grid would refine the ecoregional results and help to pinpoint key sites for conservation action in each ecoregion. For example, Manitoba’s Interlake Plain ecoregion has relatively higher biodiversity values, but lower threat. However, within a small area of this ecoregion are some of the world’s best remaining remnants of tallgrass prairie. Other well-known areas of conservation concern were split between multiple ecoregions in our analysis, such as central British Columbia’s South Okanagan Similkameen. These areas have very high numbers of species at risk and are critical to conserve biodiversity in Canada. Stepping down the scale of the analysis would support the identification of priority areas within all ecoregions will be an important next step.
Selecting priority places for conservation is difficult and is ultimately based on the species and ecosystems that we chose to value. Conserving biodiversity everywhere is also important. Protecting habitats and species across regional geographies protects representative biodiversity and is often critical in maintaining ecological services. But in a rapidly changing world with limited conservation resources, conservation requires decision making that is based on an assessment of priorities. This conservation assessment provides a framework to direct conservation actions to the ecoregions in southern Canada that have the highest levels of biodiversity and are under the greatest risk.