Abstract
Assisted migration is increasingly being considered as a potential climate change adaptation tactic even though it also comes with potential risk to ecosystems and society. When implementing conservation actions that involve risk, it is prudent to have policies and guidelines to ensure that such actions are conducted in ways that conform to regional standards and consider risks. Here, we report on a policy scan focused on assisted migration in the context of climate change adaptation originally as a protected areas tactic only, but then broadened to ecosystems in Canada beyond those boundaries. Policy scans are a useful strategy for understanding the evolving policy and regulatory landscape for a given topic and can guide the development of such policies in other jurisdictions. Our scan focused on Canada, where multi-scalar governance systems exist relevant to biodiversity and environmental management. Our comprehensive policy scan (involving scans of legislation, policies, and guidelines found online and through direct inquiries with government bodies) revealed major gaps in the assisted migration policy landscape with very few provincial/territorial or federal policies in Canada. A more rudimentary scan in the United States revealed a similar pattern. There was evidence that some jurisdictions anticipated need for such policies and even a few examples of very specific policies (e.g., seeds) that had already been developed, but there were not comprehensive policies or frameworks. Governments and other relevant bodies/organizations may wish to consider working collaboratively toward the development of robust, evidence-based policies for assisted migration given that we anticipate this conservation intervention becoming more popular as climate change impacts on ecosystems become more evident and dire.
Introduction
Climate change poses challenges to those tasked with the management and conservation of biodiversity and ecosystems (Heller and Zavaleta 2009; Bellard et al. 2012). Climate change is altering the suitability of habitats and ecosystems for species and populations that are adapted to local environmental conditions. Various taxa of flora and fauna are at risk of local extinction near their trailing-edge range limits (Wiens 2016; Gilbert et al. 2020). Limiting climate change impacts on these species will require use of novel strategies (Dawson et al. 2011; Gillson et al. 2013). One such strategy that has been the subject of extensive debate is that of assisted migration (Hewitt et al. 2011), both in protected and conserved areas for reasons of species conservation, as well as in other areas for economic, cultural, and even legal reasons. Assisted migration is an umbrella term for actions that involve the human-assisted movement of plant and animal seeds/zygotes (i.e., genetic material) or individuals from populations (Ste.-Marie et al. 2011). Assisted migration may involve the movement of organisms within their historical range, moving them just outside their natural range to facilitate range expansion, or movement further from their historical range to locations that are deemed to be appropriate for a given population (see Vitt et al. 2009; Aitken and Whitlock 2013). Approaches such as ecological replacement where new species are introduced to ecosystems to provide a functional role lost due to extinction represent another less common form of assisted migration (McCormack 2018). A detailed analysis of the various modalities of assisted migration is beyond the scope of this paper but what is salient is that we have long-been conducting assisted migrations inadvertently (St. Clair et al. 2020; Steiner et al. 2021). Assisted migration has already been attempted (Willis et al. 2009; Ren et al. 2016a, 2016b; Widhalm et al. 2020) and is being considered for further applications across a range of taxa and systems. A recent evidence map on the topic of assisted migration serves as a key resource on this topic (Twardek et al. 2023).
