In Chapter 6 and 7 of “Rambunctious Garden,” Emma Marris investigates a radical way of thinking about natural conservancy: using “invasive species” to create “novel ecosystem.”
Invasive, or “exotic,” species have been receiving criticism from the scientific community since the inception of the label. Invasive species are yet another consequence of human’s tampering with nature, whether directly or indirectly, by moving them around ever since the agricultural economic system came about. Ecologists have attempted to solve this problem by actively eradicating species deemed exotic to the native land. The “strike teams” running the show claim a seemingly honorable reason for doing this “it is […] about maintaining ecosystems that can withstand the ecological changes that will inevitably occur” (101). The argument behind “socially sanctioned destruction” (103) of invasive species get its root back in the 50’s, claiming that these plants and animals tend to destabilize ecosystems and reduce their diversity.
But the “good versus evil” dynamic hasn’t been holding ground recently due to more and more evidence against the claim that introduced species are directly correlated to extinction. Mark Davis, ecologist at Macalester University, argues that “life is in fact much messier, more dynamic, and more complex than the black-and-white battle metaphors can capture” (104). Introduced species don’t automatically compete with or prey on natives. The Britain’s blue tits should have been all starved to death if it were not for the immigration of Turkey Oaks from continental Europe, providing them with abundant gall wasps just as delicious as their previous appetite, caterpillars.
Exotic species don’t necessarily destroy all lives on Earth but instead create more diversity in the future. Some will evolve to adapt and become diverse through genetic drift. Exotic species continue to move around, evolve, and form new ecological relationships, giving birth to a new concept: “novel ecosystems.”
Aside from being ecologically harmful, sometimes the exotic components of novel ecosystems have considerable cultural value as well. For instant, most of novel ecosystems function better than native ecosystems, as evident in the case of Puerto Rico, where researchers “couldn’t measure the trees without clearing all the new undergrowth” (113). A fascinating fact about novel ecosystems is that they are defined by anthropogenic change but are not under active human management; therefore, true “rewilding” can be accomplished. Erle Ellis at the University of Maryland in Baltimore estimates that 35 percent of the world’s ice-free land is covered with novel ecosystems.
Moreover, novel ecosystems have been proven to not abase the diversity of the native population, but to restore it. For example, the natives in Virgin Island use the shades of the tantan trees from Mexico to grow, a thing they cannot do under full sun (120). Furthermore, if the goal of conservation is to keep nature in its course of evolution, then novel ecosystems are worth protecting. It is even more so since novel ecosystems present ecologists with unrecognizable patterns in their growth, thus are not under human control. Novel ecosystems can truly be “wild” in the best definition of the term, that is, without human intervention.
