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 5.1). 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 5.1 – 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.
A reintroduction may be justified if:
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.
(Falk et al. 1996; Vallee et al. 2004; Maschinski, Albrecht et al. 2012)