“Invasive Plants”: Immigrants who Nice People can Hate

Xenophobia infects perceptions of ecology

A Salt Cedar / Tamarisk tree (genus Tamarix, species unknown) at an undisclosed location in southern California. (Photo by the author)

When I first started hearing the rhetoric of the “invasive plant” narrative in the early 2000s, I was living in the progressive bastion of Portland, Oregon. I was taken aback by the vitriol being dished out by people who were otherwise prided themselves on being accepting and nonjudgmental. I concluded that many secularists, lacking a religious dogma, needed a Devil to hate, and “invasive plants” fit the bill.

I find that conclusion overly simplistic now, but it certainly contained a big nugget of truth. Through my research into the topic of “invasive plants” over the last few years—which has included a deep dive into the scientific literature, my own field observations, and many discussions with other people with varying views on the subject—I’ve come to see that the “invasive plant” narrative is more a product of culture than it is of science.

Please note my use of the word, “narrative,” which I’ll be unpacking in a minute.

The “invasive plant” narrative goes something like this: bad plants from somewhere else are harmful because they’re from somewhere else. They out-compete natives. (Some say because they reproduce faster.) Their presence costs a lot of money. They can’t change to fit in and native ecosystems can’t change to accommodate them. But it’s possible to get rid of them and doing so will make things better.

Scientifically, these declarations are all a matter of ongoing research and discussion (often heated) within invasion biology, a field that biology professor Mark Davis, author of the book, Invasion Biology, describes as “distinguished more by debate and controversy than consensus.” I have and will continue to present the science on all these declarations in my posts (and in the book I’m co-authoring with Nikki Hill, tentatively entitled, “Don’t Blame the Messengers: A critique of the ‘invasive plant’ narrative”) but today my focus is on a single cultural component of the narrative.

So what do I mean by “narrative”?

A narrative is a story that’s circulated in our society through media, institutions and personal interactions. A narrative is typically a mix of facts, myths, cultural components (beliefs), prejudices and propaganda in varying proportions. Disentangling all these elements takes time (but more importantly interest) and narratives are more often than not simply accepted at face value by people without examination.

Why? Because narratives “sound right.” On the surface, they are consistent with ideas that are already held to be true, regardless of how much any of those ideas actually are true. But what “sounds right” is a poor metric for determining the veracity of a claim. As Milo Rossi, the entertaining pseudo-archaeology debunker on YouTube, puts it: “If someone's only evidence for something is, ‘It looks like...’ then chances are they don't know what they're talking about.”

Four prominent cultural components of the “invasive plant” narrative are:

• Xenophobia, the irrational fear of “the other” (which is today’s topic)

• The belief that competition is the driving force in life

• The agricultural worldview, which divides plants into good (crops) and bad (weeds)

• The false assumption that nature is stable and unchanging

Xenophobia is an ugly trait of Western Civilization going back at least as far as the Crusades, and the United States has a long history of demonizing alleged enemies both inside and outside its borders. Something in the national character primes people to lap up fear-mongering stories about dangerous foreigners, whether it’s the Chinese, Communists, Muslims, Russians or immigrants. Tell US Americans that someone or something from somewhere else is out to get them, and they’re apt to believe it.

Some assert that this fear of the other is "instinctual" or "tribal" (yikes!) and assign it to “human nature.” But US Americans tend to universalize their prejudices in order to justify them (and to avoid looking in the mirror) and as any anthropologist or well-seasoned overseas traveler will tell you, this assertion is bunk. While there are and have been cultures who are even more xenophobic than the US, many more have been and are less so. Hospitality, tolerance and pluralism were and are held in very high esteem in many other places.

US history is full of xenophobic events and policies against both outsiders and insiders. Just a few examples are: the Chinese Exclusion Act of 1882 (and the local massacres and expulsions of the same period), the vilification of immigrants from eastern and southern Europe in the 19^th and 20^th Centuries, the century-long apartheid of Jim Crow, the Red Scares (of WWI, the ‘50s and currently), the Japanese Internment of WWII, the ongoing Islamophobia that erupted in 1979 with the Iranian hostage crisis, and the othering of various “minorities” like LGBT folks. The group who has suffered the longest history of xenophobia are, ironically, those who were here first by tens of thousands of years: Native Americans, who were subjected to genocide, restricted to reservations and are marginalized to this day. Culturally, we have always been swimming in xenophobic narratives here in the US.

Regarding “invasive species,” I can’t help but notice that the increasingly venomous rhetoric directed at them since the turn of the millennium has tracked with the so-called “War on Terror” and with intensifying anti-immigrant vitriol. In our current moment, the incoming presidential administration centered anti-immigrant rhetoric in its campaign and is threatening to implement anti-immigrant policies so draconian they have no precedent (i.e., mass deportations), so the atmosphere is getting worse not better.

Let’s look at some of the elements of the anti-immigrant narrative: they take jobs, commit crimes, cost money, don’t assimilate, and American values/culture cannot adjust to their presence without being degraded. The racist “Great Replacement” theory claims that higher rates of childbearing among immigrants as compared to European-descended people will lead to the extinction of European culture. If we deport “illegals” life will improve for natural-born citizens.

Here I’ll cut-and-paste the “invasive plant” narrative from above: bad plants from somewhere else are harmful because they’re from somewhere else. They out-compete natives. (Some say because they reproduce faster.) Their presence costs a lot of money. They can’t change to fit in and native ecosystems can’t change to accommodate them. It’s possible to get rid of them and doing so will make things better.

It’s easy to see the similarities. “Taking jobs” = “out-competes.” “Committing crimes” is their alleged encroachment. The claim that non-native plants “reproduce faster” sounds like a botanical Great Replacement theory. Estimates of the economic costs of “invasive plants” (dubiously calculated, but that’s another essay) are regularly trumpeted. That immigrants don’t “assimilate” and the country will be degraded by allowing them echoes assertions that non-native plants can’t and don’t become members of their adopted ecosystems, and that native ecosystems can’t adapt to include them. Finally, it is believed that with both immigrant humans and immigrant plants, it’s both possible and desirable is to get rid of them.

As I said above, all these declarations are currently a matter of ongoing research and debate within invasion biology, and a lack of consensus characterizes the field. That being said, there is virtual unanimity on at least one subject: eradicating “invasive plants” is now considered impossible. This should give people pause, since so many resources are currently being poured into exactly that task, with the most common methodology being herbicide use, which is problematic for a host of reasons.

I’m not saying that the accusations about non-native plants are false because the accusations about immigrants are false. I’m just pointing out that a narrative can “sound right” because it echoes another narrative that’s already familiar. The well-meaning liberals I knew in Portland were the kind of people who rightly recoiled at the ugly rhetoric about human immigrants, but inside, their worldview was still tainted by the xenophobia deeply embedded in US culture, and so it was easy for them to apply that prejudice to another target.

Regardless of what the science says or doesn’t say, the “invasive plant” narrative is clearly colored by our cultural xenophobia. By default we view “outsiders” negatively, and by applying the binary of “native” vs. “non-native” to plants we are setting up the introduced immigrants for vilification from the outset, which precludes clear-eyed, sober appraisal.

Fun fact: Designating plants as “native” and “alien” was first proposed by British botanist Hewett Cottrell Watson (1804-1881) in the mid-19^th century. A lawyer by training, Watson borrowed the terms from English common law, where they were used to differentiate citizens of Great Britain from foreigners. So from the beginning, the more-than-human world was being subjected to sociological constructions that are far too simplistic for understanding the complexity of ecological relationships.

The plight of “invasive plants” is worse than human immigrants in at least one major aspect, which is that a “path to citizenship” is denied to them, as it is to humans both legally and culturally. All but the most virulent Republican policy makers approve of legal immigration after all because they recognize economic reality. (The figure varies from year to year, but about 50% of agricultural laborers in the United States are undocumented migrant workers. The corporate class will not allow the mass deportations that Trump is threatening.) Culturally, outsiders can become insiders, as with the Irish, who faced “No Irish need apply” signs and adverts in the mid-1800s, but who eventually became ensconced in the mainstream and the elite alongside other Europeans.

But for introduced plants (of which “invasives” are only a very small subset, according to nearly universal agreement among invasion biologists) there is no way to become native, because the designation is based on a Gregorian calendar date. They will forever be outsiders, no matter how long they are here and whether they integrate into native ecosystems (leading to the formation of novel ecosystems with their own functions and processes of coevolution).

But what if, through age-old, recognized forms of speciation like genetic divergence or hybridization, a species changes enough to become a new species? One example is the case of Saltcedar / Tamarisk (Tamarix sp.), a genus of introduced trees that thrives in the southwestern United States because of the drastic anthropogenic alterations of riparian systems in the region (namely dams and irrigation diversion). The following excerpt is from “The Rise and Fall of Biotic Nativeness: A Historical Perspective” by Matt Chew of Arizona State University’s Center for Biology & Society:

Three species (T. chinensis, T. ramosissima, T. aphylla) not known to hybridize where their Old World ranges overlap are doing so in the USA, producing unprecedented, fertile hybrids. These lines may constitute new species; hypothetical Tamarix americana* (a taxonomist’s asterisk) paradigmatically native because they evolved within their current ranges and endemic because they exist nowhere else.

In other words, a newly emerged hybrid of multiple introduced species is fulfilling fundamental characteristics of what constitutes “native”: that the species evolved in a particular area and that it is found nowhere else. With Tamarix, Nature is complicating our binary, and challenging our “no path to citizenship.” Good for her! We deserve to be humbled.

Culture is like a body of water that we’re all submerged in. As currents flow through, we are all affected. Our thoughts and our feelings as individuals are taken up in the swirls and eddies, whether we want them to be or not. This is just the physics of living in a society. I recommend that we do our best to be aware of these shifts around us and within ourselves, and not allow ourselves to be carried along unconsciously.

Regarding introduced and “invasive” plants, we should not allow our policies or perspectives to be unconsciously guided by ugly cultural tropes.

Which is not to say that cultural values have no place in decision-making. Though science plays an important role in separating fact from myth, subjectivity is inherent to our MO. We have encouraged or discouraged particular plants in particular places for particular reasons for many millennia, since well before the Agricultural Revolution, and we’re going to keep doing so. But these calls must be made in terms of who our plant relations are rather than what we prejudge them to be.

In the US at present, where the vast majority of people have little or no knowledge of plants or ecological relations, the “invasive” designation, with all its cultural baggage, is dangerous because it promotes reflexive animosity and a distorted view of nature. We cannot afford to keep indulging in such an approach. That is not the path of healing our broken relationship with the living planet.