By Gary W. Kenny
This summer I've been on a mission. My objective: eliminate from our 96 acre farm and recreational property some of the invasive plant species that grow here. I've been hacking, slashing, cutting, chopping and smothering garlic mustard, goutweed, European buckthorn, European barberry, phragmites, and other alien species.
When I took up the task, my concern was primarily ecosystem-related. Invasive plant species can seriously damage, even irreparably harm, native ecosystems which are richly valuable in themselves and need to be protected. Garlic mustard, a herb imported from Europe, will spread into wooded areas and displace native wildflowers, including Ontario's provincial wildflower, the white trillium. European buckthorn, a small tree originating in Eurasia, also spreads rapidly and crowds out native tree species. Phragmites, another European transplant, can destroy huge swaths of native wetlands affecting all the native plant, animal and insect species that call them home.
Comments by two Facebook friends in response to a post I shared about my clash with invasives prompted me to think more deeply about the phenomenon of invasive species. One friend somewhat forcefully took me to task for interfering with Nature, his point being that Nature is continually evolving and will sort itself out, thank you very much. Another, an Indigenous mentor, said something similar but in the context of "All my Relations" (Mitakuye-Oyasin, Ojibwe for we are all related, humans and all things of the land). She was speaking of her faith that the "Creator" would determine Mother Nature's composition without any interference by us humans.
I took both comments seriously, especially the one by my Indigenous friend. I've come to realize that, for anyone interested in ecological and conservation sciences, the approach to invasive species cannot simply be determined by an understanding of biological (or economic) impacts alone. The associated social science as well as Nature- or Spirit-related belief systems also should be considered.
Some scientists, too, now argue that we should be more welcoming of the evolutionary diversity that can be generated by species invasions, treating it as a hallmark of the Anthropocene, the geological era in which we live. The range of species shifts resulting from environmental change and other factors do seem to make the distinction between native and non-native species much less clear than it was traditionally. Many species are portable and can take some of their ecological network or grid with them, rewiring it to allow for additional new species. The extent to which this can be seen as an invasion, therefore, is perhaps debatable. Maybe those of us who seek to eliminate non-native species are the real invaders.
So I now find myself considering the phenomenon of invasive species on several fronts. Included are the complex politics of how decisions are made about management programs. For example, some municipalities spray phragmites with powerful herbicides. In places where this tough, insidious reed grass has colonized massive swaths of native wetlands, one can perhaps understand this choice of approaches. But many ecologists and conservationists, citizens too, strenuously object to such practices because the chemicals used are believed to also kill other species - plant, insect and possibly small animals. This is the case with the broad spectrum herbicide, glyphosate, which also is thought by some medical scientists to be a carcinogen.
The psychology of how people view different types of invasive species is another factor. Domesticated cats, both loved and loathed, are a good example. A 2013 study estimated that free-ranging domestic cats in the U.S. cause the deaths of 1.3–4 billion birds yearly. That's right, billion! It's a statistic that, not surprisingly, can pit bird enthusiasts against cat owners in highly emotionally charged arguments.
The Spiritual dimension articulated by my Indigenous friend also, I believe, deserves consideration. On that subject, though, I've got to do some more thinking and will rely on my Indigenous sister for guidance.
The debate on invasives is obviously far more complex and ranges far more broadly than does my preoccupation with a few non-native plant species on my property. I will continue, even ramp up, my efforts to manage them ("elimination," the aspiration I began with is, of course, pie in the sky). So garlic mustard, European buckthorn, phragmites – you will get no quarter from me, at least for now. But I will also continue to educate myself about the social, psychological, and Spiritual as well as the ecosystem-related impacts of this beguiling and somewhat alien field of study and debate.
