In the first five chapters of her book, Rambunctious Garden: Saving Nature in a Post-Wild World, Emma Marris discusses various conservation methods only to shoot them down and advocate her proposed method of the rambunctious garden. Most of the time, the negative aspects or consequences of a method involve invasive species. One conservation technique involves restoration to a baseline with the overall goal of attaining a pristine wilderness where only native species exist. The issue with this is that most ecosystems, if not all, have been tainted by invasive species over time, which makes such an accomplishment practically impossible. Another conservation practice is that of rewilding, which heavily involves the introduction of invasive species to ecosystems in an attempt to somewhat restore balance along the food chain. A prominent counterargument to this practice is that the invasive species may not survive in the new ecosystems or that they’d adapt too well and overpower native species, effectively failing to restore the balance. The third conservation scheme is assisted migration, which is the process of relocating various species from an environment in which they are struggling to live to a more suitable habitat. Again, there is no guarantee that these invasive species will survive or not take over the ecosystem entirely.
On the contrary, the sixth chapter of the book, entitled “Learning to Love Exotic Species,” stresses that invasive species are not really as bad as they are made out to be. There is definitely a substantial amount of evidence that makes them look bad, and that seems to be what people focus on the most, but “while some exotic species are a huge problem, the vast majority are not. Science is finding that some are quite well behaved and innocuous, or even helpful” (141). Marris offers several examples to support her claims, such as the case of the Pyura praeputialis, a creature from Australia that has helped boost biodiversity on Chilean rocky tidal shores by creating a habitat where large invertebrates and algae can flourish. There are also the examples of exotic grasses becoming homes for native birds and southwestern willow flycatchers nesting in the exotic tamarisks (151-152). With those illustrations put out there, Marris then leads into the seventh chapter of her book and breaches the topic of novel ecosystems, which are “new, human-influenced combinations of species that can function as well or better than native ecosystems and provide for humans with ecosystem services of various kinds–from water filtration and carbon sequestration to habitat for rare species” (161). The term ‘novel ecosystems’ basically refers to ecosystems that have been altered by humans and invasive species over time yet are still functioning well. At this point, these exotic-dominated ecosystems that were created, for the most part, by human hands are all we really have. They may not seem ideal to some conservationists, but they “may be our best hope for the future” (176).
Up until this point, I was convinced that invasive species were something to be frowned upon. They seemed to be the one problem that always got in the way of a good conservation tactic, but that is no longer the case. By now, they are essentially unavoidable anyway. If they are profuse and valuable, I don’t see why we shouldn’t take full advantage of them. They’re probably our best shot at sufficient conservation, so we should definitely take what we can get and encourage it wholeheartedly.
