What a Difference a Year Makes!

by The Prairie Enthusiasts | Jun 2, 2026 | Inspiration

What a Difference a Year Makes!

Article by Rob Schubert, Empire-Sauk Chapter Land Manager and Site Steward

June 2, 2026

Volunteer winter work party group. Photo by Rob Shubert.

Progress at Giordano Oak Barrens and Sand Prairie has been fantastic! We’ve been able to affect more than 14.5 acres of intensive tree and brush removal since efforts at the 40-acre site in Columbia County began in January 2025. Not many of those can be counted as “completed acres,” but we have been able to accomplish a lot of the work required to restore this site.

The effort has come from multiple sources. Empire-Sauk Chapter land management staff have been crucial. Volunteer interest and turnout have been consistently growing over the past two years, with a small but dedicated group of locals now actively involved. Engaging partners has resulted in much more progress than what otherwise could have been accomplished. And, in addition to all of this, there is some degree of luck.

The first big push came with help from U.S. Fish and Wildlife Services (USFWS).

Brendan Woodall, formerly of USFWS, and I developed a suitable scope of work. We were limited by which methods could be implemented on the site. We also needed to make fast progress to build success and justify project costs. We determined that using hydraulic tree shears would be the best approach; they would allow us to impact a large area, make a clear and dramatic shift in the natural community, minimize impact to sensitive features and limit the initial follow up required.

We were able to hire a contractor to remove cedar and pine on approximately eight acres using $10,000 of available funding. This work was conducted expertly by Keith Baker of WiseAxe, LLC. Using a mini excavator and hydraulic shears, Keith was able to cut off cedars and pines at ground level, thus opening the most intact sand prairie in a way that did not result in soil disturbance or cause significant resprouting of hardwood species. Trees that were too large in diameter to remove, he de-limbed and sheared where he could reach, sometimes 20 feet up the trunk, leaving the spires which now add a bit of whimsy to the site.

Keith is an amazing equipment operator, and I wish I had been able to spend more time watching him at his craft. Unfortunately, I had to head down to Missouri for a training. While I was away, Evan Nelson helped oversee the work on my behalf. This wouldn’t be the last time Evan’s involvement proved important.

After Keith finished his work, there were brush piles everywhere. These piles needed to be consolidated and moved. Without snow on the ground and the ability to burn, the work was even harder. Evan spent multiple days moving material with his tractor. Bo Hendrickson (formerly with USFWS) also came down and spent a day moving material with a skid steer.

Without this help, we would not have been able to get all the material moved and minimize burn scars. I’d been adding about three new plant species to the inventory list each time I visited the site. Knowing there was still a lot to be discovered and that these newly observed populations were small and scattered across the site, I needed to avoid accidentally extirpating species.

Removing cedars from the most extant prairie and sand blows was the main priority. Eliminating the threat of encroachment and intensive follow-up maintenance was another major concern.

Black locust occupied three main areas when the property was acquired. Two of the areas occupy the most degraded, lowest priority areas; the third was immediately adjacent to the sand prairie.

Shala and Rob felling pines. Photo by Luke DeBiasio.

The clone was spreading. About 2.5 acres of black locust needed to be removed, and quickly! The area was also strategically important to be able to plan burn units and reintroduce prescribed fire to the site.

Black locust is notoriously difficult to control. It’s a clonal species that spreads via roots and can persistently re-sprout following removal efforts. Effective control requires, in part, specialized herbicide, which is both expensive and very capable of causing undesirable impacts to other legume species, such as lead plant and goat’s rue, especially in sandy soils.

Foliar spraying of black locust resprouts for years on end was not a viable option.

To avoid chasing black locust indefinitely, we needed to get the entire clone cut in a single dormant season. The former stand was approximately 2.5 acres. With 100 to 200 trees per acre, we were going to need to cut some trees.

Luckily for us, Evan Nelson lives just down the road. Evan owns Good Oak Ecological Services and brings the full complement of skills, equipment and knowledge it takes to implement ecological restoration and land management.

Evan brought two of his staff to join James Haas (former Chapter Crew Leader) and me, and we spent a day cutting black locust and piling and burning material. With four of us cutting trees and Evan on the tractor, we punched a big hole in the stand that day.

Most of the material that Evan and Bo moved off the sand prairie got piled and burned in the area where the black locust was being removed. Thus, we were able to achieve two tasks at once.

Before land stewardship by Eric Preston.

After stewardship by Rob Schubert.

We did not get the entire area cut in one day. We spent several more days felling trees, joined by volunteers who helped burn material. When we couldn’t burn piles due to a lack of snow, we staged cut material to be moved later.

Progress was slow without equipment. The area beneath the black locust was dense with other invasive brush like honeysuckle and buckthorn, and the densely crowded stand meant other trees like black cherry and black oak had to come out as well. And we certainly couldn’t leave the mulberry and hybrid elm.

One day, after a work party, I was alone at the site. I looked up to see a stranger had walked onto the property. He had a disgusted look on his face as he surveyed the downed trees and scattered piles of crowns.

“Are you gonna burn all this up?” he asked. “Most of it,” I replied.

He wanted the black locust and whatever other hardwood was there. I wanted to see the material put to good use and needed help getting everything out of my work area.

Jeff offered to use his tractor and trailer to remove the material, so we scheduled a day. I would fell the trees, and he would pull them out.

I showed up early to find a 60 hp tractor with a logging winch sitting at the gate. This was not what I was expecting. When he showed up with a super duty truck pulling a hydraulic dump trailer, I realized he was serious.

It was late winter by then, with conditions warm enough to thaw the still frozen ground in the forecast. We had one final day to get the cutting done. It was hard work, but with Jeff pulling out trees and no one in my felling zone, I was able to finish cutting the last black locust out of the stand.

With the final trees out, I surveyed the trees that had been felled, cut to length, and lined up, the trailer loaded, and staged logs ready for when the trailer returned empty.

Pleased with things, I looked around and said, “Not a bad day for two old guys.”

Things took a pause for a while. In the seasonal rhythm of land management, all efforts went towards burn season.

The black locust stayed on my mind. I was expecting the worst. I started seeing it come up in other areas, but I wasn’t seeing it yet at the Giordano site. I just wanted to know how bad it was going to be.

Once it did eventually come up, the deer started hammering it! I was thinking about how to get it mowed to keep it from getting too tall to foliar spray. The deer were doing this for me.

Guy (Chapter Land Management staff) and I spent a day in July spot spraying locust sprouts. All told, things were much better than expected, with re-sprouts coming entirely from remaining root stock and not from cut stumps.

When James, Luke (Chapter Assistant Land Manager) and I returned in August for a follow up application, things were looking good. Our previous application had been effective, and we treated the black locusts we missed in the densest areas and along the periphery of the clone.

Things again took a pause. The seasonal rhythm took us through seed collection and fall burning, until we again began removing trees and brush to open the lost prairie and savanna.

We had more help this time. Shala (former Chapter Land Management staff) had temporarily joined our team. Shala and I had worked together in the past doing for-profit restoration work, and she understands the production mentality that comes from doing this for a living.

Good Oak Crew cutting black locust. Photo by Rob Schubert.

We were also better organized. John Exo and Kevin McKown (Chaper members and volunteers) agreed to continue to help lead work parties. With the ability of The Prairie Enthusiasts staff to do the most difficult tree removal and holding multiple work parties a month, we were getting a lot done.

The progress has been fantastic. As Luke said, “It seems as though every time more progress was made, another interested volunteer took notice of the work being done and wanted to help.” Soon we had an almost regular crowd who would join for our workdays.

Again, we had a lot of help from Jeff and Evan. Jeff helped move and consolidate the trees we felled into burnable piles. Evan donated some of his staff’s time and equipment, allowing us to finally remove the last pines and cedars from one of the sand blows. Then he spent a few more days over the weekend moving material with his tractor and burning piles to help us prep a burn unit for this fall.

At this point, we took a pause. It’s important sometimes to stop and reflect, to appreciate things, to not have an adversarial relationship with the land. With goals accomplished and winter dwindling, we move into the next phase of the seasonal rhythm.

In all my years managing restoration projects, I’ve never had to do so much work with so few resources as I have with Giordano Oak Barrens and Sand Prairie. What we’ve been able to accomplish really has been remarkable. What I’ve described is just some of the work that has been done. There has been invasive control and other work that just doesn’t fit neatly into a single chronologic narrative. There has been survey work of various taxa; herptiles, flora, insects, birds and bats. Others have volunteered time to do the annual site monitoring, take drone imagery to document progress, manage hunting permits, collect seed, mow trails and post boundary signs; the list goes on.

And that’s what it takes. No individual has the skills and capacity to manage a restoration project; it takes a team.

This article appeared in the Summer 2026 edition of The Prairie Promoter, a publication of news, art and writing from The Prairie Enthusiasts community. Explore the full collection and learn how to submit your work here.

About The Prairie Enthusiasts

The Prairie Enthusiasts is an accredited land trust that seeks to ensure the perpetuation and recovery of prairie, oak savanna, and other fire-dependent ecosystems of the Upper Midwest through protection, management, restoration, and education. In doing so, they strive to work openly and cooperatively with private landowners and other private and public conservation groups. Their management and stewardship centers on high-quality remnants, which contain nearly all the components of endangered prairie communities.

Making the Most of Hard to Get Seeds

by The Prairie Enthusiasts | Jun 2, 2026 | Management Methods

Making the Most of Hard to Get Seeds

Article and photos by Dan Carter, The Prairie Enthusiasts Ecologist

June 2, 2026

Each year we collect what seeds we are able, and we broadcast them where we think they are most likely to succeed. That may sound simple, but a lot goes into deciding where we put our precious seeds. What factors guide those decisions? Many of us already know that some species require wet or dry, sun or shade, or acidic or alkaline or calcium-rich soil. Goat’s rue (Tephrosia virginiana) likes acidic, sandy soil. Tuberous Indian plantain (Arnoglossum plantagineum) likes calcareous soil. Other species are much less picky. For instance, false toadflax (Comandra umbellata) can grow in dry prairies and low prairies, in dolomite gravels and acidic oak barrens, in wide open prairies and in healthy oak woodlands. Where species grow, whether across broad gradients or very narrow ones, informs where we might consider spreading their seeds, but there are other factors to consider.

Let me take a step back to give some context. Much seed goes into prairie plantings on lands transitioning out of row-crop agriculture or into areas where existing perennial vegetation has been sprayed in order to “start from scratch.” Those are outside of the scope of what follows, though I will take this opportunity to urge practitioners to critically evaluate whether or not starting from scratch is the most appropriate course of action (see Spring 2026 issue of The Prairie Promoter that touches on that). Here I’m focusing on the restoration of degraded, never cultivated sites or augmentation of sites that may be old fields, but now support perennial herbaceous vegetation and may or may not be receptive to our precious seeds. Below I describe what I’m looking for in my efforts to make the most of limited resources.

Freshly clipped seed heads of wood betony (Pedicularis canadensis). We don’t want to waste these!

The locations that are the best candidates for interseeding have relatively low and sparse vegetation. Exotic cool-season grasses aren’t vigorous and only flower sparsely. The underlying soil or its covering of moss may be visible from above. Native plants like strawberry (Fragaria virginiana or F. vesca), old-field cinquefoil (Potentilla simplex) and cat’s foot (Antenneria spp.), or exotic plants like Deptford pink (Dianthus armeria) and Oxe-eye daisy (Leucanthemum vulgare) may be present. Weedy annuals like foxtail (Seteria spp.) and common ragweed (Ambrosia artemisiifolia) may be present, but they grow sparsely and only shin to knee high. Queen Anne’s lace (Daucus carota) is often present too. Together, these clues indicate that there is room for new seedlings to grow and get adequate light. They also indicate that nutrient availability is low, which tends to favor relatively nutrient-efficient conservative species over time—the same species whose seeds are often in shortest supply. Eventually, these conservative species can shoulder out the non-native species mentioned above as well as many others.

Another thing I look for is flammability. In the woods that may mean leaf litter and some sedge cover. In the open that means grasses and sedges—usually exotic, cool season grasses like Kentucky bluegrass (Poa pratensis). If productivity is a little greater due to greater nutrient availability or moisture, being able to burn and remove detritus prior to spreading seeds is very important to promote seed-soil contact and so seedlings can emerge unobstructed. Of course, burning can also keep other problems like woody encroachment at bay while conservative species establish. Repeated burning also promotes the condition of low nutrient availability in the long-term by repeatedly volatilizing nitrogen and producing little bits of charcoal that bind available nutrients. Establishment in just about any context just seems to be better and faster the sooner and more often dormant season burning occurs.

It may be drab, but after a burn to remove the thatch, this area dominated by Kentucky bluegrass (Poa pratensis) and old field cinquefoil (Potentilla simplex) is a great place to spread some seed.

I consider the presence of herbaceous invasive species. I’m not worried about most upland exotic, cool season grasses or non-native plants like the ones I’ve already mentioned. I am concerned about species that will require chemical intervention like soapwort (Saponaria officinalis) and crown vetch (Securigera varia), especially if they are distributed throughout a site. Obviously, it’s best not to seed where broadcast chemical application is already needed.

When do I plant the seeds? I generally aim to plant them more or less when nature does. For some early-ripening seeds like wood betony (Pedicularis canadensis) or bloodroot (Sanguinaria canadensis) that means I plant seeds in late spring or early summer right after I collect them. I plant most seeds that ripen from mid-summer onwards in late autumn or early winter, either after a fall burn or a few months ahead of a late winter/early spring burn.

One of a couple dozen prairie parsley seedlings (Polytaenia nuttallii) detected the spring after the planting area was burned and seeds subsequently individually poked into the soil.

If you only have a small amount of seed for a prized species, don’t spread it over a large area. Instead, concentrate the seed in patches. Many species either require or benefit from cross-pollination, so they need their nearest conspecific neighbors to be close-by in order to create adequate floral display to attract pollinators and subsequently reliably set seed and continue to increase. I go so far as to individually plant some seeds in small groupings. Depending on your capacity, it may also be worthwhile to produce plugs/transplants when seeds are in short supply.

In any case, keep records of what you planted and where. That way when something makes an appearance, sometimes after many years, you’ll remember it’s something you planted! In most cases, seedlings will appear the season after you plant seeds, but it may take several or more years before plants are large enough to be detected or begin to flower.

This article appeared in the Summer 2026 edition of The Prairie Promoter, a publication of news, art and writing from The Prairie Enthusiasts community. Explore the full collection and learn how to submit your work here.

About The Prairie Enthusiasts

The Prairie Enthusiasts is an accredited land trust that seeks to ensure the perpetuation and recovery of prairie, oak savanna, and other fire-dependent ecosystems of the Upper Midwest through protection, management, restoration, and education. In doing so, they strive to work openly and cooperatively with private landowners and other private and public conservation groups. Their management and stewardship centers on high-quality remnants, which contain nearly all the components of endangered prairie communities.

Wicking Glove Basal Bark Treatment

by The Prairie Enthusiasts | Jun 2, 2026 | Management Methods

Wicking Glove Basal Bark Treatment

Article and photos by Dan Carter, The Prairie Enthusiasts Ecologist

June 2, 2026

Many variables factor into the decision to mechanically pull, cut and treat stumps, apply basal bark treatment or use other approaches to remove invasive brush. The species and time of year are major factors. We often use basal bark treatment on invasive brush and small trees with smooth bark, and we avoid cutting and treating stumps during the period in spring when sap is flowing. Glossy buckthorn (Frangula alnus), one of our most abundant targets, has a broad sap flow season and smooth bark, so when we can’t pull it, we often use basal bark treatment.

One of the problems with basal bark treatments that are applied by spray onto trunks is overspray; sometimes herbicide misses its target or excess runs down the trunk onto the soil. We want to avoid overspray, because we often work in sensitive areas. Readers should keep in mind that there is also evidence of off-target impacts via root exudation or release that occurs during decomposition (e.g., Graziano et al. 2022, in Weed Science), so test your treatment in a small area, and always monitor treatment effects. Other approaches should be used in areas of higher quality, remnant vegetation if possible. Off-target damage is most likely to occur when many stems are treated in a small area.

To avoid overspray, we use a wicking glove or “glove of death” approach. This involves wearing chemical resistant gloves of adequate thickness (≥14 mils for Garlon® 4) that extend at least mid-way up the forearm on both hands, and a dusting glove over the chemical resistant glove on one hand (I prefer my non-dominant hand). I also wear a thinner, nitrile glove under the dusting and thicker chemical resistant gloves in case the outer glove develops a hole, but that is unlikely if rough or thorny species are avoided. A spray bottle or pump sprayer can be used to saturate the dusting glove around the thumb and first two fingers with herbicide (often 20% solution of triclopyr ester herbicide in basal oil). Then I grasp each stem and apply herbicide 360 degrees around its base. How far upward depends on stem diameter. I treat the lower 18 inches of stems above 1.5 inches in diameter and the lower foot on smaller stems. I only treat a few inches of very small stems. All stems on multi-stemmed shrubs or small trees should be treated. Apply herbicide generously—not so much that it runs off, but a bit more than it takes to simply stain the bark. Basal oil often contains a dye, or a dye may be added, but the oil itself will generally stain the bark and give it a darker appearance. This requires re-charging the glove with herbicide frequently.

Left to Right: Dusting glove over chemical resistant glove. Dusting glove saturated around the thumb and first two fingers. Treatment of glossy buckthorn stem. Glossy buckthorn after treatment.

When treated during the growing season, targets typically die within two to five weeks. They may leaf out after winter treatments and subsequently die. Other considerations that apply to basal treatments include:

Work during cool weather to minimize volatilization, which can affect very nearby vegetation and isn’t healthy for the applicator. I work on cool days or during the cool of morning when the temperature is below 70°F (often 30-60°F) and direct sunshine is not warming surfaces. Volatilization risk is greatest during and immediately after application.
Work during dry weather. I don’t apply herbicide if there is a chance of rain within 72 hours. I try to apply herbicide when I have high confidence that it will be dry for four days, especially in areas with surrounding sensitive vegetation. This needs study, but the longer the dry period after application, the better.
Don’t mix herbicide with diesel fuel. Product labels may allow it, but diesel is volatile and more toxic than basal oils designed for use with herbicides.
Wicking gloves may be re-used, but chemical resistant gloves should be discarded if not continuing treatment the same day. Chemicals slowly work their way through most chemical resistant gloves, regardless of thickness.
Strictly adhere to herbicide labels.

This article appeared in the Summer 2026 edition of The Prairie Promoter, a publication of news, art and writing from The Prairie Enthusiasts community. Explore the full collection and learn how to submit your work here.

About The Prairie Enthusiasts

The Prairie Enthusiasts is an accredited land trust that seeks to ensure the perpetuation and recovery of prairie, oak savanna, and other fire-dependent ecosystems of the Upper Midwest through protection, management, restoration, and education. In doing so, they strive to work openly and cooperatively with private landowners and other private and public conservation groups. Their management and stewardship centers on high-quality remnants, which contain nearly all the components of endangered prairie communities.

Why Prairie Restorations Look Messy – At First

by The Prairie Enthusiasts | Mar 3, 2026 | Management Methods

Why Prairie Restorations Look Messy – At First

Written by Brent J. Anderson, Minnesota Oak Savanna Chapter member

March 3, 2025

If you have ever stood at the edge of a newly planted prairie and thought, “This doesn’t look like much,” you’re not alone. I have heard it from landowners, neighbors and volunteers – and I’ve said it myself. The first year or two after a prairie planting can feel anticlimactic, even discouraging. Photos and seed mixes promise color, movement and diversity. What shows up instead often looks uneven, weedy or unfinished.

Among prairie restoration professionals, there is an old adage used to level-set expectations: “First year they sleep, second year they creep, third year they leap.” Experts know this rhythm well. Most newcomers do not – and that is understandable. We are used to landscapes responding quickly to effort. Prairies operate on a different timeline, and that early “messy” phase is not a sign of failure. It is a sign the system is getting to work.

One of the hardest mental shifts for people new to prairie restoration is realizing prairies are not gardens. They are not designed for immediate visual payoff. In the early years, the priority is not flowers – it is roots. Native prairie plants invest heavily below ground, building deep, resilient root systems that anchor soil, improve water movement and support microbial life. What we see above ground represents only a small portion of what is actually happening.

That is also why so-called “weeds” often dominate early on. Disturbed soils invite opportunistic plants responding to open space and sunlight. While no one wants invasive species to take over, the presence of certain early plants is not automatically a problem. Some have aggressive or deep roots that help break up compacted or clay-heavy soils, improving structure and water infiltration. In many cases, they act as temporary placeholders, occupying space while slower-growing prairie species establish themselves.

Management during this phase is important, but it often looks different than people expect. One of the most common and effective tools is mowing – especially during the cool season, when non-native plants thrive and grow fastest (overnight temps are below 70F – May and June). Early mowing helps prevent fast-growing non-natives from shading out young prairie seedlings that are still finding their footing. Typically, mowing continues through spring and early summer. After that point, non-native species mostly slow down and native plants can grow past them, and begin to take a competitive advantage. While most mowing efforts can lessen in July and August, it’s important to monitor the height of non-native species (e.g., Canada thistle and velvet leaf) and address out-competing stands as necessary. For smaller plots, I like to use a weed whacker or even a scissors to slowly move through the site and discover newly germinated species or get pics of bees and butterflies.

A simple rule of thumb many practitioners use is this: When non-native plants reach about 12 inches tall, mow or weed whack them back to roughly 6 to 8 inches. This practice stunts cool-season weeds without harming young native prairie plants intended for long-term establishment. Native prairie plants are also sensitive to cutting, but are often shorter in stature (especially year 1 and 2) during the cool season. For best results, it is generally wise to never trim closer than about 5 inches tall.

For small “pocket prairies” in backyards or front yards, weed whipping can be just as effective – and often more practical – than mowing. The goal is the same: reduce competition and light blockage, not create a manicured appearance. Used thoughtfully, these tools are not about “cleaning things up.” They are about guiding competition during a vulnerable stage.

Another common concern for newcomers is dead plant material left behind after a growing season. To many observers, it looks untidy or neglected. Ecologically, it is anything but. Standing stems and fallen leaves protect the soil surface, moderate temperature extremes and reduce erosion. As that material breaks down, it feeds soil organisms – bacteria, fungi and other microbes – that drive nutrient cycling. This quiet exchange between plants and soil is foundational to prairie health, even if it is not immediately visible.

I remember visiting an early restoration site a few years ago with someone who expected something closer to a wildflower postcard. What they saw instead was patchy growth, seed heads from the previous year and plenty of bare ground. We stood there for a moment before they finally said, “So … I’m not loving it. Is this the way it’s supposed to look?”

A year later, we walked the same site again. New species had appeared. The ground felt firmer underfoot. The prairie had not transformed overnight, but it had clearly turned a corner.

Prairie restorations reward patience because they are doing long-term work. In those early years, ecosystems are being rebuilt from the ground up – literally. Roots grow deeper, soil communities diversify and the seed bank begins to develop. Diversity comes later, once the foundation can support it.

Learning to read a prairie means learning to see beyond aesthetics. Messy does not mean broken. Sparse does not mean unsuccessful. Often, it means the system is doing exactly what it should. By the time a prairie begins to “leap,” much of the most important work has already happened, unseen.

If we can adjust our expectations and trust the process, we give prairies the time they need to become what they are meant to be: resilient, diverse and alive in ways that do not always announce themselves right away.

Minnesota Oak Savanna Chapter of The Prairie Enthusiasts

Our chapter includes the Minnesota counties of Anoka, Carver, Dakota, Hennepin, Isanti, Ramsey, Scott, Sherburne and Wright Counties. While our chapter prioritizes identification and management of remnant fire-dependent systems, many times we’re actively involved in restoration work – especially in creating buffers around existing remnants, or assisting landowners committed to re-creating prairies on their properties. We’re actively seeking new members committed to the protection and care of prairie remnants, managing prairies through prescribed fire, restoring degraded prairies, building new prairies and/or excited to learn about prairie projects in their own communities. We invite you to subscribe to our Chapter updates and become a member. Learn more about the Minnesota Oak Savanna Chapter here.

About The Prairie Enthusiasts

The Prairie Enthusiasts is an accredited land trust that seeks to ensure the perpetuation and recovery of prairie, oak savanna, and other fire-dependent ecosystems of the Upper Midwest through protection, management, restoration, and education. In doing so, they strive to work openly and cooperatively with private landowners and other private and public conservation groups. Their management and stewardship centers on high-quality remnants, which contain nearly all the components of endangered prairie communities.

Monitoring Bat Activity Following Prairie Savanna Restoration

by The Prairie Enthusiasts | Mar 3, 2026 | Identification & Education, Inspiration

Monitoring Bat Activity Following Prairie Savanna Restoration

Article and Photos by Robert J. Marquis, St. Croix Valley Chapter

March 3, 2025

Volunteer Joe Fusilier placing a bat acoustic recorder on a tree to monitor bat activity at Alexander Oak Savanna, June 2025.

Bats Are In Trouble

Bats provide many important ecosystem services, including the control of crop insect pests.¹ They may consume insects equal to 9-12% of their body mass in a single evening of foraging.² Bat populations, however, have been declining due to habitat destruction, pesticides, collisions with windmills and, most recently and most precipitously, due to the white-nose syndrome. In response to increasing number of crop pest insects following predator release, farmers in the eastern U.S. have increased their use of pesticides. This has resulted in an average 7.9% increase in human infant mortality in counties that have experienced bat die-offs.³

We Collected Baseline Data in 2025

Bats use echolocation to find food, especially flying insects, and to avoid collisions with foliage and woody vegetation. There is mounting evidence that invasion of natural habitat by woody plant species can decrease activity of bats. If the invasive plants are tall and dense enough, the habitat can become too “cluttered” for bats to navigate, forcing them forage elsewhere. In June and August, 2025, with the help of fellow Prairie Enthusiasts Denise Thiede, Joe Fusilier, Jay Arneson and Peter Leete, I used bat acoustic recording equipment to monitor activity of bats in Alexander Oak Savanna and in restoration plots along the Kinnickinnic River in River Hills Park in River Falls, WI. The goal was to collect baseline data on bat activity and species composition to understand how habitat restoration influences these important components of terrestrial ecosystems.

Results at Alexander Oak Savanna

We placed four acoustic recorders in June at the Alexander Oak Savanna, a 42-acre parcel that has been the object of restoration efforts since 1999 by the St. Croix Valley Chapter. During the week of June 16, 2025, we recorded activity by four species of bats: big brown bats (threatened in Wisconsin), eastern red bats (species of special concern in Wisconsin), hoary bats (species of special concern in Wisconsin) and little brown bats (threatened in Wisconsin).

Results at River Hills Park

In August of 2025, we placed acoustic recorders in four plots along the Kinnickinnic River in River Hills Park that had been cleared of “old growth” buckthorn (Rhamnus carthartica) and four neighboring control plots highly congested with buckthorn. Buckthorn had invaded the riverside approximately 50 years ago. Many of the buckthorn plants removed were 25-30 feet tall. We tested the hypothesis that buckthorn plants were tall enough and dense enough to reduce the ability of bats to navigate and to find food. This research appears to be the first experimental study to test the impact of invasive plant species removal on bat activity. In addition, there appear to be no previous surveys of bat activity along the entire Kinnickinnic River (C. Trosen, pers. comm.).

Our initial data from the Kinnickinnic River plots show that all four species of bats found at Alexander Oak Savanna also occur along the river, but in addition, silver-haired bats were recorded in riverside plots. More importantly, our initial results show that bat activity was 2-5 times higher in plots from which buckthorn was removed compared to neighboring plots with intact buckthorn canopies. We will repeat surveys during the summer of 2026, with the goal of sampling throughout the summer and in an increased number of paired plots.

Denise Thiede, St. Croix Valley Chapter volunteer, attaching a microphone cable to an acoustic bat recorder in River Hills Park, River Falls, WI. The recording equipment consists of a microphone on a five foot pole, attached by a microphone cable to the recorder, which is encased in a water proof box and cabled to a tree.

Bats Respond Positively to Restoration

This research is sponsored by the St. Croix Valley Chapter, the City of River Falls, the U.S. Fish and Wildlife Service, and tens of volunteers who helped remove buckthorn. Our approach is akin to that taking place across the planet in which bird response to habitat restoration is being monitored using song-recording equipment.

Bats are a less obvious component of the natural landscape compared to birds, because bats are active when most humans are sleeping and make sounds mostly inaudible to us. However, bats are certainly no less important in their contribution to ecosystem services compared to birds; some studies show bats actually consume significantly more insects from leaf surfaces than do insectivorous birds at the same location.^4,5 Our preliminary results suggest that efforts to restore prairies and savanna habitat in the Wisconsin-Minnesota region may increase bat activity and the ecosystem services that they provide.

Thanks to Many Who Helped

We thank the U.S. Fish and Wildlife Service, St. Croix Wetland Management District, for the loan of their equipment; Veronica Bauer, Jill Utrup, Chris Trosen, and Alex Bouthilet for training, logistics, equipment loan, and recording analyses; Evanne Hunt for support and leadership; the City of River Falls, WI, for logistical and financial support; John Lampe for pointing out the New York Times article; and the many volunteers who helped clear buckthorn from experimental plots.

References

1. Frank, E.G., 2024. The economic impacts of ecosystem disruptions: Costs from substituting biological pest control. Science, 385: 6713.

2. Kalka, M.B., Smith, A.R. & Kalko, E.K.V. 2008. Bats limit arthropods and herbivory in a tropical forest. Science 320: 71.

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This article appeared in the Spring 2026 edition of The Prairie Promoter, a publication of news, art and writing from The Prairie Enthusiasts community. Explore the full collection and learn how to submit your work here.

About The Prairie Enthusiasts

The Prairie Enthusiasts is an accredited land trust that seeks to ensure the perpetuation and recovery of prairie, oak savanna, and other fire-dependent ecosystems of the Upper Midwest through protection, management, restoration, and education. In doing so, they strive to work openly and cooperatively with private landowners and other private and public conservation groups. Their management and stewardship centers on high-quality remnants, which contain nearly all the components of endangered prairie communities.