In Chapters 6 and 7 of Rambunctious Garden, Emma Marris reinforces the main concept of this book by using examples of positive change in ecosystems by redefining invasive species as “exotic species” and discussing the need for novel ecosystems rather than exotic ecosystems. She strongly suggests that the ecological and scientific community has been stubborn on studying new ecosystems and, once again, changing their beliefs in a baseline, except the baseline now features all native species.
Apparently, scientists have turned their back on the so-called and negatively phrased invasive species that have in some cases “turned out to help rather than hinder” ecosystems all over the world (98). The “culture of fighting ‘invasive species’ is very well entrenched in conservation,” writes Marris, and “one hear a lot more about these villains” – harmful invasive species – “than the shier foreigners, and for many ecologists and conservationists, they have become the enemy” (98-9). The aim of governments for decades has been to make ecosystems invaded by other species “livable for native plants” and appropriate for unyielding conservationists, who stick to their beliefs despite the research that defies them (101).
Marris proves to us that “extinctions that are directly attributable to introduced species are quite rare,” and that ecosystems are “much messier, more dynamic, and more complex than the black-and-white battle metaphors can capture” (104). In some cases such as in Hawaii, introduced species, formally invasive, are “taking over roles once performed by extinct native species” and hybridizing with native species in no harm to their ecosystems (105). And these places are novel ecosystems: “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” (112).
When some novel ecosystems are compared to the native and relatively unaltered ones, they are “richer in species, had greater aboveground biomass, and used nutrients more efficiently” (113). Native and nonnative species exist in hybrids or in diverse mixes, where forests in Puerto Rico and so-called praires in the Midwest of the US flourish. Marris continues criticizing conservationists, by saying that they were “more interested in maximizing the number of native species than in minimizing the number of ecosystems,” blatantly ignoring the potential to assess positive change in various ecosystems (121). Instead, they pursue their own goals, whether or not writers like Marris and like-minded ecologists can persuade governments to change their attitudes and adapt, just like their environments have.
While Marris’s argument is overall very convincing, the scope of applying exotic species to worldwide ecosystems is limited; there’s a reason that she devotes a couple of pages in Chapter 6 to discuss the often disastrous consequences of exotic species in ecosystems, and why they have been called invasive species by the scientific establishment for so long. Additionally, not all ecosystems are novel, meaning that they’ve in a positive way – many simply haven’t, and they won’t for years to come. Lastly, Marris portrays the scientific community in more and more of a negative light for each chapter that she writes; I’m not so sure if they’re as stubborn and outdated in thought as she makes them out to be.
