In Chapter 5 of Emma Marris’s Rambunctious Garden, she talks about the idea of “assisted migration”. Compared to “rewilding” in the previous chapter, assisted migration seems more conceivable. In response to the degradation of habitats from human influence, some believe that moving a species to a different region may populate them and establish a permanent existence or presence. It would certainly help species like the American pika, a small mammal that dies in warm temperatures. According to Marris, “conservationists are increasingly considering moving animals [like the pika] in advance of climate change to places where they might thrive in a warmer future” (Marris 73). Although the notion of assisted migration may seem brilliant and harmless, I suspect that it will do more harm than good.
Species richness is declining. With “urbanization and its consequences occurring throughout the world” (Puth & Burns 18), we strive to save what we can of our depleting nature. However, we cannot use assisted migration as a method to do so. Existing ecosystems are complex – from microorganisms to microclimate. Humans cannot be too sure of how species interact with each other and its surroundings to live. By taking a species from one habitat to another, “organisms could die” (Marris 77). Marris also states that assisted migration may create invasive species that would push out native species. It would harm existing ecosystems in unpredictable ways. In fact, not much research has been done on assisted migration. In this chapter, Marris primarily mentions flora as opposed to fauna. When scientists studied the Torreya taxifolia of Florida, no conclusions were made as to whether climate change affected the tree’s decline. In depth research would take years, too slow for global warming. Thus, we simply cannot just relocate the T. taxifolia to where we think would be suitable.
In addition, assisted migration seems to contradict rewilding and ecological baselines. The purpose of rewilding and ecological baselines is to bring ecosystems back to the past, unaffected by human actions. Assisted migration is furthering human intervention with nature. If we truly wish to save nature, we should not continue to meddle with it. Marris even states that “if ecosystems have a correct baseline to which we must return…then we absolutely cannot move species from one area to another” (77). The concept is also leaving it up to humans to decide which species to relocate and save. What will happen to the small organisms (beetles, mites) that depend on a specific tree species? Not only may relocating species be harmful to existing ecosystems by becoming invasive species, it may also harm the previous ecosystem.
For these reasons, I presume that assisted migration should not be a conservation tool. It is a tempting method to rescue extinct-to-be species, but we cannot predict how they will do or what they will do to new ecosystems. We also do not know how their previous ecosystems will hold up. Until we are sure and find a safe solution to all these problems, we should not use assisted migration and intervene with nature any further.
