By Teresa Helms and Eleanor Duva

How to be an Invasive Species: Reflections on taking up space and thriving where you don’t belong

By Teresa Helms and Eleanor Duva

“Nudgers and shovers In spite of ourselves. Our kind multiplies:

We shall by morning Inherit the earth. Our foot’s in the door.” -Sylvia Plath, Mushrooms

In the second grade, as far as I could tell, my one true calling in life was to find, hold, and examine as many earthworms as possible. To put them in jars and watch them devour decomposing leaves. To marvel at their conspicuous non-humanness. One afternoon my best friend and I dug up a six by six foot (it might have been smaller; I was smaller then) patch of grass in my backyard in our quest to uncover the newest inhabitants of the cardboard home we had constructed. We asked for forgiveness rather than permission, and it was granted, when instead of inflicting punishment, or even replacing the grass, my dad turned the bare ground into a garden bed for my mother. It, and three more, are right outside our kitchen window, full of zinnias in the summer and birdseed in the winter.

In the time of my life when I kept jars of earthworms on my windowsill, I was only abstractly aware of gender dynamics in the sense that I had figured out that the more I acted ‘boyish,’ the more I was taken seriously. I wanted to be a scientist, and more importantly, to be listened to. As it turns out, I am still working on both. I find myself increasingly reluctant to make myself heard while my peers seem to only become more experienced, more knowledgeable, more confident than I am.

I often feel like I should already know the information that I am supposed to be in the process of learning. I sit in my forestry lecture. Third row, one of three women on the left side of the classroom. I realize how little I remember from 10th-grade geometry. Our professor cracks a joke and the hearty chuckle of men in the company of

men reverberates through the room, booming like felled timber. Most of these people look like they could blend right in with the towering eastern white pines we’ll be documenting later. When I measure diameter at breast height it’s more like ‘diameter at top of collar bone.’

I tend to carry myself gently through a system that values brashness; a world in which the meek might not inherit the Earth. This, I’m sure, would be appreciated by any delicate earthworm I were to pry from the comfort of the ground to observe. Yet the worms give me an example of how to be both. Earthworms are hermaphroditic and some are parthenogenetic; unbound by the gender binary and able to reproduce asexually. And surprising to many, they are non-native to Vermont and many other regions of the world. The areas of the Northern Hemisphere that were covered with ice sheets during the Quaternary glaciations of the Pleistocene have no native earthworm species today. The asexual life history of some has facilitated their invasive success. The first earthworms of the family Lumbricidae arrived to North America with European colonists, in soil used as ballast in ships and with plants that would establish the agriculture of colonial ‘America.’ A second clade of earthworms called pheretimoids, native to Asia, are currently invading many areas of the world, including Vermont. Through human activity, non-native earthworms have found themselves in North, Central, and South America, Northeast Eurasia, and Australia. And while most species would prefer the agreeable loamy soils of Vermont’s maple-dominated forests, some species can make themselves just as comfortable in the rainforests of Brazil, acidic soils of Alaskan conifer forests, or tundra biomes of Siberia. The success of pheretimoids, the relatively new arrivals, can be partially attributed to their remarkable ability to develop in a single season. They emerge from cocoons as soon as the snow thaws, develop into adulthood, reproduce, and die over the course of an ephemeral Vermont summer. They accumulate biomass rapidly, and ravage forest floors. They devour the precious plush of the spongy organic layer, consuming years’ worth of fallen leaves, branches, and dormant seeds, and leave behind a layer of their distinctive granular castings. They change the soil dramatically by removing the organic layer, thickening the underlying mineral soil, and altering biogeochemical processes and microbial food webs. The understory becomes unrecognizable, with just a few remaining maple seedlings that will be browsed by deer before the coming winter.

Still, this devastation is achieved through their unflinching ability to invade. They did not consider the particulars of how they might fit into their new environments. They did not need to ask for space to occupy; they took it. They are at once the meek: unseen, covert, discovered only when you dig for them, wriggling and soft in your hand; and the brash: their numbers sudden and multiplicitous, their effects altering the visual landscape of forests and the global carbon cycle. They are masters of thriving where one doesn’t belong. And further, their

popular reputation has been endeared to gardeners, farmers, and seven-year-olds alike. In the alternate context of agriculture, they are heralded as an organic solution to increase crop yields. Most of the public has never considered that they haven’t always been residents of these soils. Ecologists were the ones to raise awareness of their threat to our forest ecosystems; to take their presence seriously. In the forests I study today, earthworms have made themselves commonplace in ground that was not meant for them; beloved many years ago by small hands who didn’t yet know the gravity of these creatures’—or her own—presence. Looking at them now, I see both the threat of invasion and the brilliance of survival. So, I will learn from my old friends. They show me how to unapologetically take up space on the Earth, and to trust that my authentic existence is loud enough to be heard in any climate. I am adaptable. Capable of burrowing in even the most uninviting, frosty soils. I can be at once meek and brash; I can balance a gentle spirit with the voracity and boldness that is needed to disrupt the systems in which I dwell, giving way to new perspectives and allowing the unassuming to take root. I will keep my foot jammed between the door and the frame until I am naturalized here; until all of us are. H

Art by Reese Green