Spring is the stuff of dreams as we find solace in our studies during the long Canadian winter. Yet the dawning of botanical life with the warming sun is by no means immune to binaries of good and evil. Springing forth plant life can seem warm and inviting until we find out that some plants do not belong.
Prevailing wisdom in ecology tends to lead to a path of resistance to plants that are said to not belong; ironically, just as in social science classes where we learn that culture can divide or unite us even as we’re all humans, in science metaphysical assumptions exist that demarcate some plants as perilous to the very nature that they embody. A group of ecology experts took the hallowed ground of the academic journal Nature to elucidate an alternative view: “’non-native’ species have been vilified for driving beloved ‘native’ species to extinction and generally polluting ‘natural’ environments. Intentionally or not, such characterizations have helped to create a pervasive bias against alien species that has been embraced by the public, conservationists, land managers and policy-makers, as well by as many scientists, throughout the world” (Davis et al, online).
Whenever knowledge feels external and coercive, be it fashion trends or political beliefs or other ideas foisted upon our fertile minds, we can listen to our intuition and ponder our personal experience. It does feel a bit odd to be enjoying the countryside only to have to wade through which plants one is allowed to enjoy, doesn’t it? Like wearing sweatpants to a shopping mall, a comfortable and pleasant experience may or may not be objectively desirable. Consider the romantic Hallmark-y experience of reclining on a sunny summer slope with a lover or friend. Such a languid moment with the birds and the bees, frolicking in nature’s eternal botanical rebirth, might include a search for elusive four-leafed clovers. But, wait. The most charismatic clovers, four leafed or not, are not endemic to Canada – even our chosen moments spent scouring leafy inclines in search of a bit of Leprechaun luck are a cultural import from lands of Irish yore. Clovers, no matter their number of petals, are in many ecological minds classified as an invasive plant. Even their scientific name has a jarring and unromantic Latin moniker: Trifolium repens.
Speaking For the Foliar World, If Possible
Davis et al provide some useful context to the notion that, for ecosystem stability or cattle-grazing, some plants really are invasive and thus unwanted. It’s we humans who decide who belongs in a specific habitat. Certainly, the plants don’t know the difference! A willow tree, for instance, will induce allelopathy in its root systems to dissuade any competitor who deigns to colonize its space. Introduced or endemic, it matters not, plants compete as well or poorly as they can – although one would assume that the local ecosystem has some sort of balance achieved through the long slog of evolution. So, between subjective evaluations, likes and dislikes or (as we used to write as a heading for one part of our elementary school reports on Pandas), looks are one thing. Relative efficacy in a particular climate is another. Happily, Davis et al have summarized key issues on the topic of who in the botanical world belongs and who doesn’t.
Core to most concerns is that the abstract notion of harmony will be upset, like an apple cart losing and bruising its occupants or a tragic victim of astigmatism with eyes wandering off in different directions. (I know this from personal childhood experience). “Many of the claims driving people’s perception that introduced species pose an apocalyptic threat to biodiversity are not backed by data. Take the conclusion made in a 1998 paper that invaders are the second-greatest threat to the survival of threatened or endangered species after habitat destruction. Little of the information used to support this claim involved data, as the original authors were careful to point out. Indeed, recent analyses suggest that invaders do not represent a major extinction threat to most species in most environments — predators and pathogens on islands and in lakes being the main exception. In fact, the introduction of non-native species has almost always increased the number of species in a region”.
So, ecosystems, like our brains at AU, are constantly growing and evolving. And, as when we leave our studies for a round of conversation with our real-world cohort, reality often doesn’t match our ideals. When we step out into the great wilderness and away from the demarcated property lines of strata-managed gated communities, middle class suburbs, and general Pleasantville (the film) contradiction, we find a whole other law of the jungle. Plants come and go with the succession of different forest trees; when a fire sweeps through (fire bears the ultimate rejuvenation of landscapes be they prairie meadows or montane plateaus), the slate appears to be swept as clean as an arctic glacier. But this is not so. In fact, under the soil, rhizomes and plant seeds see their chance to go forth and flourish and multiply. No bee, endemic or introduced (as typical honey bees are, and in this sense an insect invader with our help) ever had a better fiestas than when faced with a field of fireweed. Or napweed. The latter, nasty for cattle mouths and barefoot toddlers alike, transcends the ‘invasive’ moniker and is deemed an unrepentant noxious inhabitant of meadows and pastures. Yet, squint a little through your critical inquiry AU lens, and you’ll see an array of beauty in those precious purple and white napweed flowers. How we see the world doesn’t just apply to how we see our fellow humans, after all.
Other issues in the universe of invasive plants and their botanic cohabitants also bear scrutiny. A painter or dog-walker might mostly be concerned with what looks pretty or can withstand a chew without inducing toxicity, but there’s also the twin facts of historical awareness and present-day pragmatism. While we might see a weed and pull it, at the macro level there are cultural norms and ecological outcomes to contend with – whether we adore a plant or not. Just as many plants arrive in gardens as a form of larceny from our perceptions of beauty, just as many actually escape gardens like the boy next door out of a bedroom window – only to profuse themselves across the countryside in a form of wild-oating that would make even the hungriest of foal blush. A classic BC example of a plant that escaped captivity, as it were, is Purple Loosestrife – a brilliant robe of royal purple covering roadsides and railsides alike, but one said to exclude all but its noble self. In Alberta a prime instance of similar behaviour is Yellow Toadflax – and even Chrysanthemum. The argument behind these plant’s eradication is clear; they take up space where original diversity once prevailed. However, the history of invasive plants parallels the colonial history of western Canada.
To The Historical Inquiry We Go!
“In the early 1830s, British botanists began distinguishing between species known to have been introduced to an area by people and those without such a history. By the late 1840s the terms “alien” and “native” had been adopted, and a century later, those labels gained moral force with the rise of environmentalism: natives were natural, innocent, untainted by human association; aliens, like their human enablers, had detrimental “impacts,” not effects. Defence against “biological invasions” became a prominent goal of conservation biologists, who decided by acclamation that “invasive” alien species were a dire threat to biodiversity.” Strong words there, Buckos! But these are acclaimed scientists speaking, not your garden variety social media spout-offs.
This perception of a dire and impending attack on harmony, that rich and delightful metaphor redolent of church choirs and Grey Cup halftime show sing-a-longs is in fact more an arts major aesthetic than pure empirical science. And that’s what these experts are pointing out: when subjective values enter into science, calamity can ensue. See, as winds blow so do seeds go – since the last ice age eight thousand years ago, every plant we see in Canada basically had to arrive, or re-arrive. Witness the fact that “the concept of nativeness lacks reliable ecological content—it simply means that a species under scrutiny has no known history of human-mediated dispersal”. Even more pointedly is the raw fact that “not all introductions are so dramatically detrimental as the examples popularized by conservationists and the media. The devil’s claw, for example, a plant “native” to Mexico and surrounding regions, has had no discernible effects on Australia’s existing flora or fauna, despite being recently condemned as a threat to the continent’s biodiversity—long after its introduction in 1860s.” Two examples here in BC that I encounter in my forestry work, where we do vegetation plots to see how forest ecosystems are regrowing after a fire or when replanted after logging, are Grand Mullein and Orange Hawkweed. Whereas both can become a bit, er, excessive in a pasture, something itself a managed and wholly unnatural (that is, nonhuman nature) setting, in mountain forests invasive weeds like these occur rarely, sporadically, or not at all. Typically, when we depart a roadside where soil has been disturbed by human activity (such as logging or farming) invasive weeds don’t get a toe-hold. Or roothold. So at AU we can apply our thinking caps to even this most scientific of a concept, the invasive weed issue, and out of facts find a social science paradox. Harmony, like beauty, is after all in the eye of the beholder. And for there to be an eye and then ideas you need a human participant. So next time you search for a four-leaf clover, remember that you need not feel guilty that the plant exists so much as pleased to have green rather than pavement under your picnic blanket.
