- Reintroduction is not the first step toward the conservation of a species, but rather follows a careful process of gathering information about the species, threats, alternative actions, and future needs.
- There are several considerations for justifying a reintroduction.
- Acknowledge that there are clear reasons to avoid reintroduction.
CPC does not support or promote reintroduction as an alternative to in situ ecosystem protection. All those working in plant conservation firmly agree that the priority is to conserve species in situ and to preserve wild populations in natural habitats in as many locations as possible. Reintroduction is never the first action to take for a critically endangered species, even when crisis is imminent. First steps for species in dire straits must be ex situ collection, threat control, and habitat management (Guerrant et al. 2004).
Prior to conducting any reintroduction, thorough status surveys and careful review of rarity status and threats should be undertaken (Figure 4.1). Reintroductions should only be considered if habitat protection is not possible or if the taxon is critically imperiled and appropriate sites and propagule source materials are available. CPC recognizes that reintroductions may need to be used as a tool to mitigate the impacts of climate change, because some in situ rare plant populations will be unsustainable within their current historical ranges.
Figure 4.1 Possible threats to a reintroduced population include those imposed directly by humans that cause habitat destruction or degradation; changes in temperature, precipitation and sea level resulting from climate change; biological threats from insect or mammalian herbivores or pathogens; changes to the condition of the habitat via invasive species incursion, changes in disturbance regime or frequency (i.e., fire, storms, flood events), altered or degraded microclimate conditions due to changes in succession and competition, changes in soil microbial communities, and sustainability threats caused by funding constraints, personnel changes, changes in land protection, land ownership, or land management.
To determine whether a species should be considered for reintroduction, it should meet the criteria described in the “Questions to Ask When Justifying a Reintroduction” box. If the species does not meet these criteria, a reintroduction should not be attempted at this time. If conditions should change in the future, a second evaluation could be done. For some taxa, it may never be appropriate to conduct reintroductions. For others, changed conditions and improved horticultural, genetic, and ecological knowledge may make it feasible to conduct a reintroduction at a future time.
Document the species status and distribution.
- Conduct surveys and obtain population information.
- Map or obtain maps of the known populations to determine the current and historical distribution as it relates to ecoregions, habitat, geology, and soil type.
- Assess habitat-specific population information (Knight 2012). In each population, count or estimate the percentage of reproductive, juvenile, seedling stages, and if possible, measure growth and reproduction.
- Note abiotic and biotic conditions in occupied patches. Whenever possible, quantify these factors (for example, near adults and seedlings record the canopy cover, associated species, plant density, soil moisture, light, and other factors).
Questions to Ask
When Justifying a Reintroducton
A reintroduction may be justified if:
- Species is extinct in the wild OR;
- The distribution of the species is known and there are few, small, and declining populations; AND
- Alternative management options have been considered and conducted, yet have been judged to be inadequate for long-term conservation of the species; AND
- Threats have been identified; AND
- Threats from habitat destruction, invasive species, land conversion and/or climate change are imminent and are uncontrollable. Species has high risk of extinction if only managed in situ.
If the species meets any one of the following criteria, then do NOT proceed with reintroduction. Consider ex situ conservation practices (Guerrant et al. 2004). If the unmet criterion is resolved in future, then re-evaluate.
- Reintroduction will undermine the imperative to protect existing sites.
- Previous tests indicate that it has not been possible to propagate plants or germinate seeds.
- High-quality, diverse source material is not available.
- Existing threats have not been minimized or managed.
- The reintroduced species may potentially negatively impact species in the recipient site via competition, hybridization or contamination.
- There is evidence that the reintroduced taxon would harm other threatened and endangered species or conflict with their management.
- The reintroduction is not supported legally, administratively, or socially.
- Suitable habitat is not available, nor understood.
(Falk et al. 1996; Vallee et al. 2004; Maschinski, Albrecht et al. 2012)
Ascertain the threats and, when possible, take action to remove, control, or manage them.
- Note specific abiotic and biotic factors that may be causing the population decline. Realize that threats may be direct or indirect (Dalrymple et al. 2012).
- If you are currently monitoring the population, note conditions present so that you will be able to pinpoint changes in future years.
Engage land managers in discussion about best options for the species conservation.
- Attempt or consider all alternative management options before considering reintroduction.
- Discuss which options are feasible to implement.
- Ensure the population will have long-term protection and management (that is, invasive species removal, controlled burns, etc.).
Do not proceed with a reintroduction if you cannot justify it. Use other conservation options for the species.
Do no harm to a recipient community or to existing wild populations.
- Consider whether your reintroduction will do any harm to a recipient community or to existing wild populations. If so, consider alternative conservation strategies.
- Determine whether potential collateral impacts of the species in the recipient site are negligible. There is little threat of hybridization, invasion, or contamination.
- The reintroduction will not undermine the imperative to protect existing populations and their habitats.
Determine that the reintroduction is feasible legally, logistically, and socially.
- Because laws governing rare species protection vary by location and jurisdiction, it is essential to discuss and verify that the reintroduction plan is supported by the law, legal authorities, the recipient site landowner, and the public.
- Ideally, the reintroduction will have been identified as an important step for preserving the species in a legal document, such as the species’ recovery plan or a conservation action plan.