67 ~ Invasive species I love

The watercress spring

Last February, during a talk I attended at the Wisconsin Garden Expo, the speaker invited the audience to share the names of some of their favorite native plants. One woman nominated watercress, a plant that’s also dear to me. Although of a kindred spirit and palate, she would have lost points on Jeopardy with that answer. Watercress is native to that middle ground between Asia and Europe, the area of Greece, Turkey and Iran.  It was such a prized food, for both its flavor and medicinal benefits, that humans quickly spread watercress around the world, taking it with them wherever they went. Captain James Cook (not Kirk) credited watercress with preventing scurvy amongst his crew on his long voyages of exploration across the Pacific in the 1700s. 

I’m tempted to name watercress as my favorite non-native, invasive species, but it might not qualify. According to Wikipedia’s definition, “An invasive species is an introduced organism that becomes overpopulated and harms its new environment.”

Perhaps the term ‘invasive species’ needs a bit of unpacking, given that the definition brings us into a gray area – placing ‘invasive’ in the subjective eye of the beholder (much like ‘weed’ – which means any non-woody plant growing in a place where we don’t want it).  I doubt that few people, if any, consider watercress overpopulated and environmentally harmful. It’s tasty, and is narrowly restricted to our purest springs and small streams. We tend to view watercress as a sign of environmental health and stability rather than dysfunction.

But what about earthworms? Most earthworms in Wisconsin are non-native (the glaciers erased any that might have been here before, and subsequently they hitched a ride with European immigrants). Although appreciated by us gardeners (and robins and fishermen/women), have they harmed Wisconsin’s environment?  Possibly.  Before earthworms arrived (or returned) from Europe, forest floors in the northern US were covered by a much deeper, year-round layer of duff and fallen leaves. Earthworms, those inveterate (and invertebrate) mulchers, fundamentally changed and decluttered the forest floor. It’s possible that the erasure of the deep duff layer by worms increased muddy run-off into streams, and also made it easier for other woodland invasives, such as garlic mustard, to take hold in the worms’ wake.

And brown trout?  Another European import, and now the most abundant trout in Driftless streams. It’s beloved by trout fisherman and an important economic asset for fishing tourism in Wisconsin.  But it’s not loved by Wisconsin’s native brook trout, which brown trout outcompetes (much to the ongoing consternation of DNR fish managers).  Are browns, by definition, ‘invasive’? It depends on who’s answering the question.

Everything is perspective. That bain of gardeners, the invasive weed creeping Charlie, is a prized and cultivated salad green in Southeast Asia. In Laos where I’ve lived and worked, it’s served as a garnish with every bowl of rice noodle soup. And for years I loved purple loosestrife, that Wisconsin roadside tower of glory, before learning it was a harmful invasive. Eco friends have tried to educate me out of my affection for loosestrife, without much success.

Here’s the thing, maybe the path forward to an easier world isn’t to educate the clueless like me to hate invasives, but to get others to accept, and maybe even love, them.  What meaning does ‘invasive’ have in any case, when it’s all one planet?  Species have constantly and forever tweaked and changed their range distributions, and perhaps acceptance of that inevitable reality will help us all breath a bit easier. Every form of life on Earth is ultimately a native of the ancestral supercontinent Pangaea and the single sea that surrounded it. Garlic mustard didn’t ride into my woods on a meteor from Alpha Centauri (and even it if did, it’s one universe…). Garlic mustard is of the Earth, and lately also that part of the Earth we call “North America”.  I’m willing to accept that.

The next time bile starts rising at the sight of an invasive, it might help to look in the mirror. The most damaging invasive species in North America, by far, has been Homo sapiens, especially those who recently invaded from Europe. And even Native Americans arrived on the continent fairly recently, mostly likely from Asia. The only place where humans are truly native is the continent of Africa. Everywhere else we’re an ‘invasive’.  So let’s cut garlic mustard some slack - we’re homeys.

I don’t write any of this lightly.  Many of the wonderful neighbors along my road have invested a lot of time, money and sweat into native prairie and woodland restoration on their lands, and I am a grateful beneficiary. But for most of them, I think it’s an act of love for particular plants and plant communities, and the ‘native’ story of those plants, rather than hatred of and an attack on invasives.

This is an important distinction.  One of the most harmful invasives humans have introduced to the world is hate.  Non-human animals experience aggression, fear, and maybe even anger, but I doubt they have the same capacity for hate as humans. It’s a toxic, overpopulated emotion that has accompanied humans like Norway rats, and I’m all for rooting it out, everywhere we can. Hate is simply frustrated love, so it can be an easy switch to make.

I don’t have a lot of extra time or resources myself for ecological restoration, and so instead I’m learning to accept and even love invasives where they are. I look forward to a future meal of watercress salad, fried brown trout, maybe a side of pasta with garlic mustard pesto, and a dessert of invasive European blackberries, with a vase of purple loosestrife on the table. Life will be good in that moment.

Red-tailed hawk update

A few hours after my last post, at the direction of the DNR, I euthanized the gorgeous, but weakened, red-tailed hawk I found. It wasn’t an easy task, for either of us (one of the first books I bought as a kid was World of the Red-tailed Hawk, by G. Ronald Austing; I worshipped that book and its subject, and still do). That said, I’m grateful to be the one who ended its life, if it had to be done. Later, a DNR technician drove out to the farmhouse to collect the carcass, for testing for avian influenza. I’ll let you know if and when I get word of the result.

A couple of things I know already: First, although an adult (and probably a male, judging by its smallish size), the hawk was neither very young nor old, judging by its feather molt and eye color (young red-tails start with straw-colored eyes, which deepen to a beautiful, rich brown as they age). It was at least two years old, and probably not older than 4 or 5 (red-tails can live more than 25 years in the wild).

Second, even if a wildlife rehabilitor would have accepted it for care (which none will at present, due to the avian flu outbreak), and even if it didn’t have avian flu, it was likely too far gone, too thin, from whatever ailed it to be brought back. Raptors in low condition reach a point of no return, when no amount of feeding or provision of electrolytes can bring them back. This red-tail was almost certainly past that point (it would also have been illegal for me to try to help it, lacking the permits to possess it). On to the next stage of its journey for this hawk.