Weeding: Tending My Neighborhood Arroyo

Cañada Rincon arroyo with Siberian elms invading.

I’m sitting at the breakfast bar in my condo, my arms scratched, body sweaty, and muscles sore, eating a grilled cheese sandwich with green chile and avocado for late dinner, feeling tired and quite satisfied. I’ve just spent an hour with my well-loved loppers and hand-saw, cutting invasive Siberian elm trees (Ulmus pumila) from the arroyo that runs through my neighborhood.

It’s a classic northern New Mexico waterway, where the water itself is hidden below ground most of the year, except after rains and snow-melt. That sub-surface “stream” helps recharge the groundwater table, and nourishes extra-lush (“lush” for this high desert, that is!) plant growth along it: scattered clusters of cottonwood trees (Populus fremontii) with New Mexico privet (Forestiera pubescens) under them, plus piñon pine (Pinus edulis) and Rocky mountain juniper (Sabina scopulorum) along the edges.

Looking down on the arroyo from the street.

The silvery-green shrubs in the photo above are rubber rabbitbrush (Ericameria nauseusa in the language of sciencechamisa in Spanish), whose flowers turn whole swaths of the landscape golden in fall, providing what my friend Lauren Springer Ogden calls “the last bar open” for pollinators of all kinds, especially butterflies, beetles, and native bees. Its chaffy seeds are critical food for bushtits and other small songbirds in the hungry months of February and March, when other food is scarce.

Painted lady butterfly nectaring on a rubber rabbitbrush shrub in late September. 

Dotted among the rabbitbrush are smooth currant (Ribes cereum) with early flowers that feed hummingbirds and red berries songbirds seek out, Apache plume (Fallugia paradoxa) with its bee-friendly flowers and feathery and edible seeds, and narrowleaf yucca (Yucca baileyi) with the tall, candle-like flower stalks that nourish yucca moths and aphid-slurping orioles; plus dozens of kinds of wildflowers, including my favorite, long-flowered gilia (Ipomopsis longiflora), beloved of evening-flying sphinx moths for the nectaries at the base of those long floral tubes.

Long-flowered gilia opening in the evening, ready for white-lined sphinx moths

This bounty of native plants that provides homes and food for wildlife large and small lines the arroyo–unless Siberian elms move in and take over, growing thickets of deep-rooted trees that suck up the underground water, shade out the sun-loving native flora, and drop a thick layer of leaves and small branches that smothers the soil and is as flammable as dry kindling.

And take over they do: Siberian elms are ubiquitous throughout the arid West, imported here from Asia as a hardy, fast-growing, drought- and cold-tolerant tree that would form windbreaks and provide shade in places where shade was scarce. All of that proved true, only the trees took far too readily to their new environment, growing rapidly, and producing thousands of seeds that skittered before the wind, piling up in drifts in every nook and cranny, and sprouting much too readily.

Which wouldn’t be bad if they provided anything close to the rich habitat of the native arroyo flora. One Siberian elm may make a great shade tree for a yard; a whole thicket of them is silent, home to few insect species and fewer birds, in contrast to the lively arroyo habitat outside the thickets. Siberian elms are the definition of an invasive species: one that comes from another place, has few if any relationships with the existing natural community, and proceeds to multiply and ruin the habitat, a playground bully run amok in the landscape.

I’m determined to not let Siberian elms take over Cañada Rincon arroyo and its joyous chorus of birdsong and wildflower blooms. I’m also determined to do what I can to give the native community resilience in the face of catastrophic climate change. So in my spare moments, I get out my tools, pull on my gloves, and walk over to the arroyo to remove another few elm trees.

That hand-saw is as long as my forearm and my hand with fingers extended–it’s a formidable tool!

I’m a steward for this section of the arroyo, which means I pick up trash (there’s not much), and pull and cut invasive weeds. I’m only allowed to use hand tools, and I’m not allowed to cut down trees larger in diameter than a wrist, which I interpret quite liberally. Today I sawed down two ten- or twelve-foot tall elms (that’s one of them in the middle of the photo at the top of the post), plus removed a few that were only a few feet high, the size of fat fingers at the base (for those I use the loppers).

I employ the trees whole for erosion control, dragging them over to the arroyo banks and placing them in eroded rills, trunk upstream, branches downstream. There they act as water retarders, slowing the flow and letting sediments accumulate to stem bank erosion. As long as these teenage elms don’t have any seeds, I like to put them to use, rather then just consign them to the dump.

A freshly-cut elm dragged into a side channel for erosion control. 

When I’ve spent my available time and energy, I dust myself off, clean my tools, and take a moment to look down “my” stretch of arroyo, noting the absence of a few more more Siberian elms. There are many more to remove, but I’m not daunted. I’ve reclaimed urban waterways before, and I know the power of even one passionate person (even if that one is small and getting old!) to make significant change.

The truth is, the work is good for me: Using hand tools to remove small trees is very good exercise. And by helping this stretch of arroyo become more resilient in the face of climate change, I’m boosting my resilience, and my store of hope, too.

Looking downstream, with fewer Siberian elms in view…