Assisted migration is a very controversial concept that has been hotly debated in ecological circles in recent years. As climates continue to increase in temperature as a result of global warming, species will naturally move toward the poles and uphill to cooler climates. This is an extremely slow natural process and some of the migrating species might not be able to migrate on their own. This can lead to extinction and the destruction of ecosystems. As a result, many ecologists and people with special interests have suggested assisted migration. Assisted migration involves physically moving species to cooler and more ideal climates so they are able to thrive and prosper. Opponents of assisted migration argue that the species might not be able to adapt to these new environments and that they may become invasive. Opponents also point out that only certain species that are aesthetically pleasing or economically valuable will be moved, which can destroy ecosystems. Although assisted migration is a relatively new concept, it was successfully applied for Florida torreya trees and is being utilized by foresters in British Columbia. While assisted migration has been used in rural forests, it has yet to be attempted in urban ecosystems.
I believe that assisted migration will be a very useful tool for urban ecosystems. First off, urban ecosystems are far from pristine and already have many invasive species, so opponents cannot argue that assisted migration will taint them. Secondly, assisted migration can increase species richness in urban ecosystems. As shown by Puth and Burns in their 2009 study, there have been major declines in species richness in the New York metropolitan area. Looking deeper, their article shows that species richness has declined in all urban habitats in the New York metropolitan area. Perhaps assisted migration can play a beneficial role and increase species richness in urban ecosystems, which will have a positive effect on the environment. Finally, assisted migration in urban areas can benefit endangered species. Endangered species that are native to climates that are similar in temperature to the urban environments where they are moved might be able to prosper. This can prolong the lifespans of these species.
One problem with utilizing assisted migration in urban ecosystems is that buildings cause urban areas to have elevated temperatures. Since the goal of assisted migration is to protect species against global warming, this is a variable that can have a negative effect on many species. Another problem with utilizing assisted migration in urban ecosystems is that there is limited space. As a result, there might not be many places to put new species. The final problem is that the results are unpredictable. Assisted migration might lead to harmful invasive species and pests being introduced to urban ecosystems. Therefore, assisted migration in urban ecosystems should only be used for species that are sure to thrive in their new environments and do not pose a threat to other species in the area.
Assisted migration can definitely restore some biological diversity to urban areas. However, it is unknown if all assisted migration will have a positive effect. In addition, assisted migration will cost a tremendous amount of money and require a lot of time and effort. Assisted migration needs to be attempted on a larger scale before it is carried out in urban ecosystems. More research needs to be conducted to determine its drawbacks and benefits.
