The damage done by “invasives”—the word, not the plants
How narrative effects nature literacy
The widespread use of the word “invasive” to describe certain plants has done great damage to the public’s understanding of plants and ecology, more than any other narrative in the last generation I would argue.
The word “invasive” is at odds with the reality of what plants are and of how life on the planet works. A vast world of complexity is flattened into a grossly oversimplified drama of good vs. evil. The multifaceted, nuanced interplay of response and adaptation among countless species with each other and their fluctuating conditions is reduced to a single perceived side effect misrepresented as a cause. Worst of all, the word manufactures a perspective that distracts us from threats to biodiversity that are, in contrast, unequivocal (with habitat destruction at the top of that list).
Negative personification
“Invasive” is undeniably a negative word. An “invasion” is a disastrous event. An “invader” is an enemy. Whoever or whatever is “invasive” is nefarious.
We also consider an invasion to be an intentional act, planned and organized, with goals. An invader doesn’t invade their neighbor accidentally.* They know what they’re doing and they mean to do it.
So whatever species of plant pinned with that label is instantly a villain. The word is judge, jury and executioner. All discussion is shut down except for the best way to eradicate it. The species is just bad, end of story.
But what makes sense in the construct of civilized human affairs doesn’t apply to plants and nature.
It should go without saying that plants do not plan or organize military-style campaigns as does an army, nor are they motivated by greed as is an imperialistic nation. War as humans wage it is a purely human enterprise. Yes, some animals squabble over territory but that’s hardly the same, and to attribute Napoleonic behavior to plants is a bridge way tf too far.
In short, describing plants as “invasive” is fanciful personification, not objective description.
Personification is a figurative linguistic device in which human traits are attributed to more-than-human creatures or things, such as animals, plants, natural phenomena or inanimate objects. At best it’s an effective artistic device, when it’s understood as a kind of metaphor. At worst it’s misleading, when it’s taken for literal fact. A lovely example of personification in literature is Homer’s “rosy-fingered Dawn” (ῥοδοδάκτυλος Ἠώς) in the Odyssey. A less charming case is Tennyson’s “Nature, red in tooth and claw” from In Memoriam (1850), which dreary cynics ever since have cited to ascribe brutal agency to the more-than-human realm.
But the rising of the sun is not literally a goddess with pink digits, and the living world is not literally a monster with fangs dripping blood, and likewise, plants do not literally engage in willful acts of conquest. It would be nonsensical to set policy as if the sun really were a goddess or as if nature really were a vicious beast, or if, likewise, plants really were aggressive villains. They’re not.
No such thing as a bad plant
There’s no such thing as an innately wicked plant. First off, nature doesn’t work that way. Ecosystems aren’t about sin and virtue. Those are the moral concepts of some human cultures, imposed on the world but not at all actually inherent in it.
Secondly, as humans, we do indeed make judgments about whether it’s desirable or undesirable for a particular plant to be in a particular place at a particular time. Ultimately, it’s always a subjective call, based on criteria that are relative to time, place and culture, and there’s nothing wrong with that. We weed our veggie gardens, or take down a dying tree that threatens to fall on our house. In both those cases, whether the weeds or the tree is native or not is irrelevant. We want our carrots to size up and our roofs to remain intact. Such judgments are not specific to agriculture or urbanized life in our current era. Indigenous people who didn’t farm or live in cities also chose to encourage or discourage particular plants in particular places through landscape modification (fire, water diversion, moving rocks and earth) and by purposeful propagation. Methods and choices varied by region and over time, and plants that were cherished by some peoples were ignored by others. The common through-line is that in neither the present nor the past, or in either colonial or indigenous societies, has there ever been a static universal standard.
Hence why the word “invasive” is so problematic as applied to an entire species: it’s universalizing, and dismisses time, place and culture. Once a plant is added to that dreaded list, meaningful context is pitched out the window, and the species is declared harmful no matter what. We no longer stop to consider whether the accused plant is demonstrably causing harm in a particular place, like, in this alley or on that roadside, in this vacant lot or on the edge of that field, at this park or in that preserve.
Of course what’s totally ignored is whether the plant is beneficial in any way. Though the vitriolic rhetoric of the “invasive plant” narrative implies that this is impossible, biologists—including invasion biologists—have found that introduced plants indeed can and do play positive roles in their new homes. It’s never black and white.
To name just one example of many: a study in Davis, California found that over 40% of the butterfly species in the city have “no known native hosts in the urban-suburban environment” because so much native flora was wiped out by development. The author of the study, noted entomologist Arthur Shapiro of UC Davis, warned: “Were certain alien weeds to be eradicated or their abundance greatly reduced, the urban-suburban butterfly fauna would disappear. This might be regarded as an unfortunate, and perhaps intolerable, side-effect of such programs.” Count me as someone who would regard that as intolerable, Professor Shapiro! Anti-“invasive” purists who prefer a native-only flora would be well-advised to keep his findings in mind and at the very least employ a strategy that’s more additive than subtractive. The first step doesn’t always have to be to rip everything out or spray it, but the word “invasive” really doesn’t inspire thoughtful deliberation. Too often it’s just “get rid of it!” <smh>
The problem of plant blindness
Here in the US in the 21st Century, most people don’t know much at all about plants, and don’t even notice them most of the time. Botanists James Wandersee and Elisabeth Schussler coined the term “plant blindness” to describe this syndrome. This ignorance is a tragic state of affairs, and it’s made worse by the word “invasive” because people are given a false sense of knowledge. It’s like, “I don’t know much at all about plants and don’t even notice them most of the time, but now I will call this one bad.” Yikes! They didn’t pick up anything new except another unthinking prejudice. As if we don’t have enough of those already! Nothing real was learned. That really sucks.
As a lover of plants—all plants—I honestly really resent the “invasive” narrative because it disinclines people from learning about plants and ecology. It just gives them a quick and easy story that jibes with common Western cultural biases (xenophobia; life as competition; nature as a stable and unchanging; obsession with purity, etc.). People are told to just hate and move on. Ugh.
This is dangerous. Our lack of conscious connection with plants and place and the planet is an ongoing crisis, one that empowers the degradation of the living world to grind on with awful intensity, whether far away or nearby. We need to heal this wound by re-embracing endearing relation with the ever changing intricacy of actual ecological interactions. Only then can we move forward in a way that’s healthy for everyone, human and more-than-human alike. But our already poor situation is aggravated when, instead of urging people to reconnect with the plant life around them, they are instructed to simply demonize it instead. We’re already deep in a hole of ignorance and we’re digging ourselves deeper with this superficial story line.
And then there’s the science
If it helps to know this, the science of invasion biology itself is not as dogmatic as the popular “invasive plant” narrative is. If you dive into the peer-reviewed literature (which I have over the last seven years), you’ll find out that the field is characterized by debate and a lack of consensus on many subjects, including whether the word “invasive” should even be used at all. There is a recognition that loaded, emotional language is not objective and can, in worst case scenarios, color the perceptions of researchers and how they interpret their results. Surveys of the field’s literature—by people in that field—show that bias (not just in language but in breadth and depth of data) is an ongoing issue that needs addressing. So we could take a cue from them.
Basically, ecological interactions are complicated but the word is deceivingly simplistic
I hope you can see why I get so frustrated when people invoke the word “invasive” as if nothing else needs to be said. This one-dimensional narrative doesn’t tell anything close to the whole story. And were we to pursue it unthinkingly, we would do even more damage than we’ve already done, given a) the inevitable collateral damage that results from eradication efforts, and b) the existential need to perceive and relate to the plants differently than we do now.
This piece borrows from the book I’m co-authoring with Nikki Hill tentatively entitled “Don’t Blame the Messenger: A critique of the ‘invasive plant’ narrative.” Paid subscribers have access to previews from this work, and will receive a copy of the full draft when it’s completed.
*Okay actually accidental invasion is a thing. See this entertaining article at toptenz.net.
I have to respectfully disagree with this much of this article. However you distinguish plant and animal species that arrive suddenly, most often by human action, in areas distant from their place of origin, they often have a devastating effect on the existing local ecosystem into which they are released. Ecosystems develop and change over time, with new species arriving or evolving, but the pace of this transformation is typically slow in Nature, so that species have a chance to co-evolve. In this process, they have an opportunity to genetically adjust, both to compete with each other or/and collaborate.
If, however, you take an Asian species of chestnut, load it into a ship and transport it, complete with its fungal hitchhiker to a zoo in New York City, you take a chance of releasing a pathogen that is completely novel to the North American chestnut tree and in a few decades extirpate a tree that is foundational to the local ecosystem, killing not only billions of American chestnut trees (formerly a fouyndational species of the local woodlands) but also depriving local wildlife of the nuts on which much of it depended seasonally for food, and causing the disappearance or even extinction of many species of insects that fed on American chestnut foliage. This has huge impacts up the food chain and destabilizes the whole ecosystem.
Non-indigenous plant species we casually release into our gardens and the surrounding landscapes typically provide much less in support to the local flora and fauna. This is precisely why so many of the new arrivals spread explosively. The indigenous insects commonly cannot feed on them, and the indigenous pathogens are not adapted to preying on them. The new arrivals are also commonly less vulnerable to many of these plants have allelopathic qualities that essentially poison indigenous indigenously evolved flora, further degrading thee local ecosystem.
Yes, there is considerable debate among ecologists about the impact of releasing non-native species of plants and animals into local ecosystems. That is the nature of science - argument and debate is how it refines its understanding of the data it collects. However, the overwhelming consensus among ecologists is that the casual introduction of non-indigenous species is a very hazardous practice.
With. regard to Dr. Shapiro's findings about the adaptation of Californian insects to introduced plants, I would like to point out that this is a process every ecologist to whom I have ever spoken has said would surely occur. Such adaptations are an intrinsic part of evolution. The pace of the introductions, however, is again an issue. Dr. Shapiro sent me a personal communication rebutting another ecologist who spoke on my radio program and pointed out that Asian "butterfly bush" (Buddleia davidii) while a useful nectar source for Californian lepidopterans did not in general provide a host for their caterpillars. Dr. Shapiro informed me that he had identified two subspecies of a California butterfly that did use Buddleia davidii as a larval host. Given that butterfly bush was released into North America over a century ago and the numbers of it that have spread through wildlands in California since then (crowding out native species that native insects had previously depended on), Dr. Shapiro's observation underlines how slow an ecosystem is to recover from such human interferences.
As we confront a mass extinction caused by our self-serving degradation of the global environment, I do not believe that we can afford to continue the sorts of radically destabilizing, ignorant behavior which has brought us to the brink of this disaster. We can argue about semantics and whether we are verbally discriminating against the species gardeners and others are casually transporting around the globe. But if you look at the data, the damage this has caused and still is causing is clear.
I so enjoyed this thoughtful, well-researched dive into the word “invasive,” which strikes me as a fancy term for the equally misguided “weed.” Years ago, I read an essay by Michael Pollan, “Weeds Are Us,” that completely flipped how I think about all plants — and our relationship with them. When we step out of the center and see the bigger picture, all sorts of insights can come. Thanks for this.