Emma Marris discusses the topic of assisted migration in Chapter 5 of her book, “Rambunctious Garden.” Because of problems with climate change, many species will have difficulty adapting to the changing environments around them. This may cause extinction of the species since many animals are unable to migrate or relocate to a new ecosystem. There may be “barriers in the way” preventing them from moving, including seas and cities to block an animal’s migration path and even a road could be a hindrance to small animals (75). Some species might also not be capable of moving large distances in order to move to an environment better suited for them. Assisted migration may be a solution to such problems, and it involves humans transporting a species into a new area for them to continue to survive. As Sally Aitken, professor of forestry genetics says, “Assisted migration is going to be necessary to save some species” (94). Whether or not ecologists are willing to undertake assisted migration is another question. It is impossible to transport every single species in an area and there are several other problems associated with assisted migration. The species being moved might not be able to adapt to the other environment, perhaps because of an unobserved element such as “specific soil microbes or microclimatic condition” (77). The results are unpredictable and an assisted migration might not save the species. The relocated species could also potentially harm the new ecosystem by becoming an invasive species and pushing out the native ones (77). Another problem encountered by assisted migration is the high cost of transporting the species.
While there may be some problems and difficulties with assisted migration, it can also be a useful tool for urban ecosystems. As Marris points out, “Surely assisted migration of these ecosystems would just be a continuation of the care our species has put into them for thousands of years” (87). Since humans have already been interfering with ecosystems, assisting the migration of several species in order to save them sounds reasonable, especially in urban ecosystems, where the number of species is declining.
“Most of those that did report data over time showed declines in species richness [in the Metropolitan New York area],” explained Linda Puth and Catherine Burns in their paper, “New York’s Nature: a review of the status and trends in species richness across the metropolitan region.” There is a large downtrend in the variety of species of many animals, most often in a native species (Puth, Burns 21). Assisted migration could help restore the species richness in an area by bringing a species to a certain area where it will prosper. Thus assisted migration may be a helpful tool in saving species by improving their living conditions, yet there are also several risks involved that should also be taken into consideration.
