Conserving plant species at risk in Canada: land tenure, threats, and representation in federal programs

Canada’s Species at Risk Act (SARA) was designed to prevent extirpations and extinctions and aid the recovery of species in Canada (SARA 2002). As of December 2018, plants and lichens together form the single largest group of species listed under the legislation as extirpated, endangered, threatened, or special concern (37% of the total; Government of Canada 2018). Unlike the United States Endangered Species Act (US ESA), SARA does not automatically protect listed species and their habitat, except in areas of federal jurisdiction (SARA 2002). However, in the United States, the prohibition against destruction of listed species or their habitat does not apply to plants (Evans et al. 2016). Therefore, the automatic protection afforded to plants in Canada—as in the United States—depends on the extent to which they occur on federal lands.

We expect that most populations of listed plant species in Canada are not on federal land, where they have legal protection. In Canada, biodiversity is highest in the far south, which is also where the human population density is highest (Coristine and Kerr 2011). While there are some exceptions—for example, the endemic flora of the Athabasca sand dunes in northern Saskatchewan (Environment Canada 2013)—most listed plant species in Canada are associated with vegetation types that reach the northern limit of their North American range in southern Canada. These include the Garry Oak savannahs of southwestern British Columbia; the grasslands of the North American Great Plains extending into southern British Columbia, Alberta, Saskatchewan, and Manitoba; the Carolinian forests of southern Ontario; and the Atlantic Coastal Plain in Nova Scotia (Argus and Pryer 1990; Parks Canada Agency 2006; Environment and Climate Change Canada 2018a). Most of the land in these regions is not federal land. For example, most forests in southern Ontario are privately owned (Ontario Ministry of Natural Resources 2016). But the actual proportion of plant populations on private land has not been quantified. This is clearly an information gap, and it also presents a precarious situation in which the combination of incomplete knowledge of the locations of plant species at risk and a lack of federal protection on most lands could lead to the loss of populations before they are even known.

In addition to determining legal protection, land tenure could affect the threats faced by plant species at risk and trends in their populations. For example, Hatch et al. (2002) found that plants found primarily on federal land in the United States were less likely to be threatened by construction of residential areas, roads, or utilities than plants on other lands. In the United States, listed plant species found primarily on federal land were also more likely to be improving in status, although this pattern could be a result of better monitoring or easier implementation of recovery actions on federal land (Rachlinski 1998; Hatch et al. 2002). In Canada, human intrusions and disturbance, mainly via recreational activities, pose the most frequent threat to plant species at risk (McCune et al. 2013). Given the sometimes heavy recreational use of federal lands, including National Parks, this threat might actually be greater for species found primarily on federal land. There has been no analysis of trends in plant species status over time in relation to land tenure in Canada.

Canada’s management of species at risk emphasizes stewardship first, rather than regulation of activities on private lands (Olive 2014). To support this goal, the Canadian government created programs for the protection and stewardship of species at risk. In this paper, we examine two of the biggest programs, which take different approaches to contributing to the conservation of species at risk and for which we could make the links back to the individual species targeted. The first is the Natural Areas Conservation Program (NACP; Nature Conservancy of Canada 2016), which matches federal funding with contributions from private donors or environmental nongovernment organizations to purchase or otherwise secure private land for conservation. This program has been funded through three separate agreements, totaling $345 million from 2007 to March 2019 (Environment and Climate Change Canada 2018b). The goals are to secure land for long-term conservation, implement stewardship activities on secured lands, and build capacity within the land trust community. The second is the Habitat Stewardship Program (HSP), which began in 2006, and allocates approximately $12.2 million per year to projects that conserve species at risk and that prevent other species from becoming a conservation concern (Environment and Climate Change Canada 2018b). HSP projects can be carried out on private land or provincial Crown land, and applications are open to nongovernmental organizations, citizen groups, as well as provincial, territorial, and municipal governments. For example, the Native Plant Society of Saskatchewan has received funding from the HSP for their “Rare Plants and Ranchers” project. Over 2100 projects have been funded by the HSP so far, with a focus on supporting implementation of SARA (Environment and Climate Change Canada 2018b). In the United States, plants at risk receive far less funding for recovery actions compared with other taxa (Negrón-Ortiz 2014). In Canada, no one has quantified how much attention or resources are allocated to plants through the NACP or the HSP relative to other taxonomic groups.

In this study we focus on plant species at risk in Canada. We analyze official status reports and related documents and publicly available data on federally funded programs to determine: (i) how many plant species at risk occur mainly on private land, (ii) whether species found mainly on private land differ in terms of the main threats they face or changes in their status over time compared with other plants at risk, and (iii) if conservation actions for SARA-listed plant species are funded under the NACP and the HSP in proportion to their numbers.

We used the online Species at Risk Public Registry to compile a list of 234 vascular plant, moss, and lichen species listed as Extirpated, Endangered, Threatened, or Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC; Government of Canada 2018). Note that we use the term “species” to indicate species, populations of species, or sub-species assessed by COSEWIC. We also include lichens in our tally, although they are not technically plants, because of their similar characteristics (e.g., photosynthetic, sessile). COSEWIC is an independent panel of experts that has been assessing the status of species in Canada since 1977 (The Committee on the Status of Endangered Wildlife in Canada 2019) and provides guidance regarding which species should be listed under SARA. However, not all species recommended for listing by COSEWIC receive legal status under SARA.

Our findings show that there is a strong need for Canada to promote stewardship of plant species at risk on private lands. Most plant species at risk listed under the SARA are not found primarily on federal land and as a result do not benefit from the automatic protection granted under SARA. In addition, more than three-quarters of plant species at risk have been found on privately owned land. Further, we would expect the recorded number of populations on private land to increase with more surveys on private land. For example, surveys of private forests in southern Ontario regularly turned up previously undocumented populations of plant species tracked by the province or listed under the SARA (McCune 2016; McCune et al. 2017b; Rosner-Katz et al. in press). We do not know what proportion of monitoring and other conservation research in Canada occurs on privately owned land, but we suspect it is low compared with publicly accessible land (cf. Hilty and Merenlender 2003). Species distribution modeling can be used to make field surveys for plant species at risk more efficient (Guisan et al. 2006; McCune 2016; Rosner-Katz et al. in press), but this does not eliminate the need to increase field surveys targeting plant species at risk, particularly on privately owned land.

We did not identify substantial differences in the threats faced by plant species at risk depending on their occurrence on private lands. This echoes the findings of Hatch et al. (2002) for endangered species in the United States and highlights the fact that Canadian plant species at risk face many threats, regardless of land tenure. On federal lands in Canada, species at risk (and their critical habitat) are legally protected from outright destruction. Yet, even on federal land, species at risk still face pervasive threats such as human intrusions and disturbance, invasive species, climate change, pollution, and other threats. It is crucial to mitigate the threats to plant populations on private lands as well, given that small, privately owned properties provide important habitat for populations of at-risk plants (e.g., McCune et al. 2017b).

The levels of risk for most Canadian plant species have not improved according to COSEWIC status assessments, and the likelihood of improvement does not vary with primary land tenure. However, the results of the re-assessments serve to emphasize the uncertainty regarding the true status of many plant species. Nine out of the 15 species that improved in status did so only because increased survey effort following their listing led to the discovery of previously unknown populations. Again, this illustrates the need to find ways to encourage surveys and monitoring, particularly on private lands that are less travelled by botanists.

Recognizing the need for greater protection on private lands, and to support the “stewardship first” intent of the SARA, the Canadian government has invested hundreds of millions of dollars in the NACP and the HSP. These programs have contributed to the purchase and protection of nearly 400 000 ha of habitat for species at risk (Nature Conservancy of Canada 2015), and thousands of projects for research, restoration, or education to benefit species at risk (Table S2). However, plants are not represented in these programs in proportion to the number that are listed. Our findings are similar to findings from other countries in which plants receive less attention than some other taxa (e.g., Martín-López et al. 2009; Oldfield 2010; Havens et al. 2014; Negrón-Ortiz 2014; Evans et al. 2016; Broadhurst and Coates 2017). SARA does not include provisions for putting a higher priority on some taxonomic groups, other than to rank species according to risk of imminent extinction. However, assessments of the process by which species: (i) are listed under SARA, (ii) receive a Recovery Strategy, and (iii) have critical habitat designated revealed biases related to taxonomy and other factors (e.g., Mooers et al. 2007, 2010; Findlay et al. 2009; McCune et al. 2013; Bird and Hodges 2017; Creighton and Bennett 2019).

We identified three possible explanations for the relative lack of emphasis on plants in the programs we examined. First, if managers implicitly placed a higher priority on species listed as endangered over those listed as threatened or special concern, and if fewer plants were listed as endangered, then these conditions could explain the weaker representation of plants on NACP properties and among HSP projects. However, a higher proportion of plants are listed as endangered than other taxonomic groups, except for arthropods and molluscs (Government of Canada 2018).

A second possible reason for a lower priority on plants is that many SARA-listed plant species are not endemic to Canada. As noted above, many are associated with vegetation types that extend south into the United States, and some are secure south of the border. However, the observation that Canadian plant species at risk are often at the northern edge of the species range is also true for other taxonomic groups, and the SARA contains no provision for global status to affect efforts to conserve species in Canada.

A third possible explanation is cultural “plant blindness”, resulting in fewer organizations and researchers working on plant conservation, in turn resulting in fewer plant-related applications to the programs (e.g., Balding and Williams 2016). Although the administrators of the HSP can only fund projects if they receive an application, they do set funding priorities and could target historically under-represented taxonomic groups, including plants, which could then encourage more applications focused on plants. To support future analyses of program results, we also recommend that the HSP consistently assess and report which species are targeted by the projects it funds. Future work could also examine how the NACP identifies and acquires possible lands for purchase and protection.

The high proportion of plant species at risk on private land and the stewardship-first approach of the SARA necessitate a strong focus on protection of private lands through purchase or voluntary agreements and on programs that engage with landowners to foster awareness and stewardship of these species. Canadians consistently show commitment to the conservation of species at risk, but they resist regulation, desiring incentives and advice instead (Gray et al. 1993; Sutherland 1997; Henderson et al. 2014; Goodale et al. 2015; McCune et al. 2017a; Olive and McCune 2017). The HSP has contributed to some very successful, multi-year programs to promote stewardship of plants on private lands. Two stand out for their documented successes: “Plants on the Edge: The Atlantic Coastal Plain Flora Securement and Stewardship Project” run by the Nova Scotia Nature Trust (Nova Scotia Nature Trust 2009) and “Rare Plant Rescue”, part of the Stewards of Saskatchewan program run by Nature Saskatchewan (Vinge-Mazer and Ranalli 2012). Landowner-focused programs like these require reliable, sustained funding. Establishing relationships with landowners is a long-term endeavour, which requires continuity to build trusting relationships between landowners and the organization running the program (e.g., Janssen and Williamson 1996; Sutherland 1997).

At least one of the hotspots for Canadian plant species at risk, southern Ontario, lacks a coordinated landowner stewardship program. Conservation managers began landowner contact and stewardship programs in this region and had measurable success in the mid-1980s and early 1990s (Hilts and Moull 1985; Duynstee 1997), but lack of provincial funding led to the demise of these programs, and others like them (S. Hilts 2013, personal communication; Phair 2014). While committed local environmental groups and volunteers have managed to keep some programs going (e.g., Phair 2014), most regions in southern Ontario lack any such programs. These gaps could be filled by the federal government placing a higher priority on projects fostering stewardship of SARA-listed plants on private lands.

Finally, if plant species at risk in Canada are to recover, the Canadian government must actively solicit and fund projects that include conservation, research, and monitoring of plant species at risk, especially on private lands. With better data on where plant populations actually are and their viability, land purchases made under the NACP or programs like it can better select properties that support plant species at risk.

We thank Hiba Ali of Environment and Climate Change Canada for compiling the HSP data, and Jeannette Whitton and three anonymous reviewers for helpful comments on earlier drafts. JLM was funded by a postdoctoral fellowship from the Natural Sciences and Engineering Research Council of Canada.