These plants are merely doing what plants do and have always done- surviving. And one of the ways they’ve historically done this is by moving their ranges. The ice ages are a great example. Here in North America, many plant species migrated south during our last ice age and moved back north when the glaciers receded. And currently we’re seeing many tree species inching their ranges north due to climate change. Are these plants “invasive” or climate refugees? The lack of nuance in the conversation and, in some cases, the unwillingness to even engage in a discourse around this is problematic because there are few simple answers. Humans have certainly driven some of these range changes by creating numerous opportunities for plants to move around by fragmenting and disturbing landscapes through development, contributing to climate change and participating in a globalized economy. Perhaps these plants changing their ranges is a symptom of all this disturbance and ecological degradation humans have wrought, however the field of invasion ecology would have us thinking the plants are to blame and the solution to eradicate them, almost always with the egregious chemical glyphosate aka Round-up. How is applying poison ecological restoration? Particularly when the problem is quite often coming from upstream.
There’s also the issue of plant time vs human time. When looking at the issue of native vs non-native, we must take the geological time scale into consideration and be willing to accept that we might not know what plant migration looks like in an age of climate chaos and in the midst of the global mass extinction event which is currently underway. Nature is dynamic and landscapes and plant communities are always in flux. Looking at nature as a time stamp or freeze-frame when considering what plants “should or shouldn’t be somewhere” is coming from an assumption that nature is static, rather than in process, which is a scientific and ecological falsehood. Plant succession is a small scale example of this- the process of a field turning into forest, for example. This begs the question, what metrics are we using to define native vs non-native? What scientific tools are we using to assess when an “invasion” is underway vs succession or ecosystem changes within a geologic timescale? These are difficult questions to answer and there is no consensus within the scientific community globally as to what constitutes a native plant.
In their native habitats, so-called invasive plants are often early successional species and when they arrive in a new land, they’re often filling an ecological niche. This is because they tend to thrive in all the disturbance humans are so good at creating with roads, construction, resource extraction, and so on. If it seems like these plants are “taking over,” it’s quite possibly a symptom of the larger ecological degradation occurring all around us, not the root cause, and often they’re growing in and creating habitat in areas that most plants can’t tolerate. This disturbance us humans tend to leave in our wake is part of why certain plants follow us around and “invasives” are often some of the most widely distributed plants in the world. I like to zoom out and really consider what it means for certain plants to be found almost everywhere humans are and bring an animist lens into it too. What might these plants be telling, were we willing to put down the Round-up long enough to listen? What might it mean to re-frame the narrative and consider our relationships with these plants as symbiotic and mutually beneficial or even reciprocal, rather than combative? What truly constitutes an invasion or ecological disruption? When many of these plants tend to be wildly medicinal and provide ecological benefits such as erosion control, wildlife food and shelter, phytoremediation, building materials and more? It’s almost like they’re the clean-up crew that come in after humans pass through and mess everything up and are, yet, still offering us their gifts despite organized campaigns against their very existence.
In regard to thinking about our language around this, in the field of ecology plants are called “non-native invasives,” “invasive alien species,” “alien species,” and “colonizer species.” This is a language of separation and these terms immediately elicit a somatic response of danger and fear. If this language sounds similar to the xenophobia currently at-large in our country, it’s because it is! In the U.S. the terms “illegal alien,” “alien,” and “unauthorized alien” are used in myriad of immigration statuses and, as we know of course, no person is “illegal.” We can borrow less-charged terms from ecology and instead of saying an “alien” or “invasive” species, we can call it introduced, opportunistic or displaced plant relative. Instead of calling a plant a “colonizer species” we can say it’s an “early successional species.” Instead of a “colony” of plants we can call it a “stand.” And I’m sure that with a collective thought process, we can come up with even better re-frame terms for all of these instead of reinforcing this doctrine of xenophobia, divisiveness, and separation from nature in our language around plants. Our words are a simple and powerful way we can actively resist and feed less into the myth that these plants aren’t somehow still a part of nature.
Part of being a bioregional herbalist means working with so-called invasive plants as part of our materia medica and holding them with equal value and reverence as we would any other plant. They are certainly abundant, and a practical benefit is they usually can be harvested from areas where harvesting native plants is prohibited (just be sure the area isn’t sprayed with herbicides), like conservation areas, since they’re often so maligned, making them super accessible as well. Here in the northeast a few of my favorite introduced medicinals are Japanese Knotweed (Fallopia japonica), Wild Rose (Rosa multiflora), and Barberry (Berberis vulgaris, B. thunbergii). Their gifts are myriad, if we are willing to listen.
And I 100% acknowledge that this topic is multi-layered and complex and I share loads of resources below to go further!