Chapter 5 of “Rambunctious Garden” looks into the topic of assisted migration. Assisted migration is when humans move a species that is close to extinction in its current environment to a new environment, in hopes that it will thrive there. The book uses the example of the pika and the Florida torreya to illustrate how beneficial assisted migration can be.
The pika is a small mammal that lives on mountains. Pikas live on mountains because they can only survive in cold climates. Spending just a short amount of time in warm weather can kill a pika. Human use of fossil fuels has increased climate change, which has made many environments hotter than they usually are. As the pikas climate gets hotter, it has to move higher up the mountain to live in a cool environment. However, the top of a mountain has less space than the bottom so there might not be enough room for the pika to survive on the mountaintop. In addition, a pika cannot survive a trip down the mountain and up a higher mountain nearby.
Marris also discusses how assisted migration can benefit the Florida torreya tree. This tree is found on the east coast of the Unite States, starting if Florida. However as Florida gets warmer and drier, it is harder and harder for this tree to survive there. To prevent the species from going extinct, conservationists want to spread its seeds further up North, to places like North Carolina. In the northern part of the Unite States, the tree can grow and thrive in the climate.
Not everyone agrees that assisted migration is a good thing. The ones that support it argue that since humans are responsible for the climate change that is threating many species, it is their duty to assist them and find them better places to live. Opponents argue that introducing species to new environments is a recipe for disaster as they can become invasive and dramatically alter the environment that they are introduced into.
Assisted migration should be an option that conservationists use, but not often. While the move will hopefully help the species, conservationists are taking a huge risk when they move the species to a new place. In addition, if people want to create a pristine wilderness area, this tactic defeats the whole purpose as it involves a lot of human intervention. The best strategy would be to focus on finding alternative sources of energy for humans to use. That way we would reduce our burning of fossil fuels and slow the heating of the earth, which would allow many species to survive in their native environment, without the need for being transported to a new one.
