Invasive species can feel like an overwhelming problem. It’s one of the greatest challenges facing conservationists worldwide, whether it’s lionfish in Florida or bluegill in Japan or garlic mustard in Iowa.
Sometimes the scale of an infestation seems impossible to overcome. By definition invasive species often completely overtake a site and resist any attempts to control them. They’re hard to kill and quick to multiply. It can feel like they’re Obi-Wan Kenobi threatening “if you strike me down, I shall become more powerful than you can ever imagine.”
Couple that with the fact that most landowners have understandable reservations about herbicide and chainsaws, and it’s easy to see why so many people throw their hands up and give in to the dark side.
But to borrow another cliché quote, the longest journey begins with a single step. We took a few steps here at Osborne in January battling some low-hanging fruit, literally. We’ve laid out an action plan for dealing with the copious amounts of bush honeysuckle infesting several parcels throughout the park.
Invasive bush honeysuckle (two species, Lonicera maackii and L. tataria around here) has enjoyed a particularly robust population at Osborne for decades. Curiously, it’s not much of a problem at our other parks, and I think I figured out why when we were digging through some old newspaper articles about Osborne recently.
One article from 1968 mentioned planting “wildlife packets” provided by the Iowa Conservation Commission (the precursor to the DNR). I couldn’t find the species list, but I do know that honeysuckle and many other invasive species we currently spend tons of time and money controlling were intentionally planted decades ago.
The reasons for including non-native species to improve wildlife habitat vary, but ironically the same traits that make them invasive today often made them appealing generations ago: rapid growth, tolerance to a wide range of conditions, and resistance to herbivory and other disturbances.
Fast forward to today, and we’ve got honeysuckle – a thicket-forming shrub with semi-appetizing berries for birds – dominating the understory through large sections of Osborne’s forest. The worst infestations are among the pine plantation, along the nature trail, and in an area known to have been planted with otherwise bird-friendly shrubs.
In other words, the most vigorous populations seem to coincide with a lot of other intentional plantings. So while I can’t say for sure the honeysuckle got some anthropogenic assistance, it seems likely. But perhaps I’m just convincing myself of that story because it actually offers some hope.
While it looks like a huge, intractable problem today, it's probably a relatively new one, at least on the ecological scale. The field of restoration ecology is full of stories where healthy, native biodiversity has held on, suppressed under the weight of an invasive infestation, and quickly recovered when the weight is lifted. Heck, we have plenty of such stories right in our own parks.
It also suggests that we’re not totally at the mercy of uncontrollable variables like wind or water dispersion, or the location of a bird’s restroom break. If we had to plant it, and now we get rid of it, all we have to do to control it going forward is just not plant it again. We’ll have to monitor for the occasional vagrant, but it didn’t get this bad “naturally,” so our controls aren’t sandcastles waiting to get wiped out by the next wave.
Armed with that knowledge, we sat down in early January and laid out some priority areas and strategies. Our order of operations goes 1) Identify honeysuckle. There’s a few desirable species that might masquerade as honeysuckle, but a few simple cues can make it easier. • Opposite branching – buds and twigs are directly across from each other. Dogwood and viburnum also have opposite branching, but both have larger buds and lack the… • Striped bark – Honeysuckle has pretty characteristic long stripes, especially on larger stems, as opposed to the more chippy or plated bark on viburnum and dogwood. • Hollow pith – Snap a twig open, and honeysuckle will have a hollow channel on the inside.
2) Cut down the honeysuckle – all of it. This shrub sends up a lot of suckers, and near the base will have many smaller stems, any of which can provide adequate photosynthesis for the plant to survive. A simple handsaw is all that’s needed, but you might come back for the really big ones with a chainsaw.
3) Treat the stumps. Yes, with herbicide.* Glyphosate (roundup) works if the mix doesn’t freeze, or an oil-based selective herbicide with triclopyr as the active ingredient can give more all-weather control.
*I understand and sympathize with reticence to using herbicides. Depending on the scale and available equipment, there are other means. Cutting back all the stems multiple times per year will kill it, or wrenching out the roots, but both of those options come with their own collateral damage. Treating cut stems in the dormant season minimizes the risk to adjacent vegetation and soils. I have yet to meet a single professional land steward or ecologist who has completely removed herbicides from the toolkit. They often provide the most efficient and least-damaging means to restore natural conditions. The devil, as always, is in the details: read the label and follow the label in full.
4) Pile the stems, spacing the piles ~100 feet or so apart.
This is *almost* an entirely aesthetic choice, but there are reasons for piling instead of leaving. The piles themselves will provide habitat for small rodents, reptiles, and birds, and pollinators. Any remnant berries hanging on the twigs will be consolidated instead of scattered through the woods, making follow-up control easier. Piles can be burned too, provided it happens relatively quickly before it gets occupied by forest friends.
And that’s it!
It’s an easy, effective means to get out and do some good in the woods. Aside from the ecological restoration, it provides a lot of personal restoration too. Nothing beats the satisfaction of hard-earned fatigue in service of a meaningful cause, especially during the time of year when it’s hardest to get ourselves out into the big beautiful natural world.
Getting these bullies out of the midstory will give the suppressed vegetation a chance to reestablish, and at Osborne we’re fortune to have a lot of amazing woodland wildflowers who will quickly fill the void left behind. I know this because I’ve seen it. I did just a small section about five years ago on a wild hair with a few hours to kill one day. Today, that small section has replaced the honeysuckle with native sedges, wildflowers like Jacob’s ladder and hepatica (spring ephemerals especially suffer, since honeysuckle leafs out at the same early time and shades them out), and a few native shrubs like gooseberry and prickly ash.
That’s the most heartening point of this whole endeavor. It’s not a lost cause, it doesn’t revert back to the degraded condition right away, and it produces real value almost immediately.
I’m not naïve, I recognize that at some point a bird will poop a honeysuckle seed in these woods and we’ll have to take care of that too. But every year it will get easier. And if we think on the landscape scale, if every woodland owner and steward took just a few days or even hours each year to battle back the infestation, eventually we'd run out of seeds for birds to transport.
But we all have to do our part, we all have to take that first step. To borrow one last cliché from the loraxe (sic)…
The likely headline so far from the CCCB has to be the developments on the campground at Osborne. Crews came out at the end of December/early January to remove the trees (and honeysuckle!) from the future site of the campground. It's incredibly exciting to see the site in these early phases! With the basic opening achieved, it makes the finish line feel that much closer and achievable.
January also saw an immense amount of classroom programs, timber stand improvements, and even a few field trips for intrepid young students trying to bring the Gary Paulson classic "hatchet" to life.
My my, February looks like a busy one...
Tomorrow, February 4th, Clayton County Pheasants Forever will host their annual banquet at Johnson's Reception Center in Elkader. Come and hobnob with fellow conservation advocates and one of the finest non-governmental habitat organizations in the country!
On February 14th, we'll be hosting a romantic snowshoe walk at Osborne to take in the fresh air, gaze at the stars, and celebrate deepest darkest winter with that special someone (and a naturalist from Osborne. We're special, just... maybe not as romantic.)
On February 23rd, we're looking forward to hosting all manner of public & private partner organizations for Coffee & Conservation, a casual gathering to swap stories and talk shop about what everyone's been up to and hopes to achieve in the near future. With so many new faces in the local conservation community, it will be an exciting chance to see how we can all help each other in the broader geographic context.