Most people have the relationship backwards. The common story goes something like this: plant native wildflowers, help the bees, save the pollinators. Good instinct. But a new study out of Iowa State University just flipped that narrative on its head, and the implications for anyone doing prairie restoration work are bigger than they might look at first.

Pollinators don't just need the prairie. The prairie needs the pollinators right back.

What the ISU Study Actually Found

ISU ecology professor Brian Wilsey and doctoral graduate Nathan Soley spent four growing seasons, starting in 2020, working with as many as 68,000 flowers across 54 plots of restored prairie southwest of Ames. Their goal was to figure out what happens to plant communities when pollinators are removed from the equation.

The setup was elegant and a little labor-intensive. Some plots had their flowers bagged with fine mesh fabric, the kind used in bridal veils, to keep pollinators out while still letting in light and moisture. Other plots were hand-pollinated by Wilsey and Soley themselves. The rest were left alone as control groups.

What they found, published this month in the Ecological Society of America's journal Ecology, was stark. Among animal-pollinated plants, viable seed production dropped by 50 percent. Species diversity among those plants fell by 27 percent. Overall plant species richness across the plots fell by 23 percent. That's not a minor adjustment to the ecosystem. That's a structural unraveling.

As Wilsey put it in the ISU news release: "Before this study, I would have never thought that pollinators were this important to maintaining biodiversity. It really opened my eyes."

The Extinction Vortex

On a recent episode of the Prairie Farm Podcast, Kent Boucher and Nicolas Lirio discussed the study at length, and Kent landed on a term the researchers themselves use to describe where this leads: the extinction vortex. Fewer pollinators means fewer viable seeds, which means less plant diversity, which means even fewer pollinators, which means even less plant diversity. Around and around it goes.

What's especially unsettling is what Wilsey believes may already be happening. He says the data suggests prairie plant composition may already be shifting toward wind-pollinated species and self-pollinating species. Ragweed and its relatives, in other words, rather than coneflowers and bergamot. That shift is slow, but it appears to be in motion.

Bob St. Pierre of Pheasants Forever and Quail Forever has said on this podcast before that roughly one in three bites of food Americans eat depends on pollinators. The USDA puts it at about 35 percent of global food crops depending on animal pollination to reproduce. But the prairie case isn't even primarily about food production. It's about the structural integrity of an ecosystem that everything else depends on. Deer, pheasants, songbirds, wild turkeys, they all live and die by the plant diversity of their habitat. Pull the pollinators out and you're pulling the thread that holds the whole thing together.

What This Means for Reconstruction

Reconstructed prairies already start at a disadvantage. As Kent pointed out in the same podcast conversation, about 0.01 percent of Iowa's original tallgrass prairie remains. The vast majority of what gets planted now is reconstructed, not remnant. And reconstructed prairies tend to simplify over time. Big bluestem crowds out forbs. Diversity dwindles. It's a well-known pattern and until now it was mostly attributed to the lack of large grazers and the dominance dynamics of aggressive warm-season grasses.

The ISU study adds another layer to that story. It suggests the pollinator decline is also a direct driver of the diversity collapse in reconstructed prairies. The two problems feed each other.

Justin Meissen of the Tallgrass Prairie Center has noted that Iowa's recommended seeding rate for reconstructed prairie is 40 seeds per square foot, and he'd like to see that doubled to 80. But if half of naturally produced seeds aren't viable because pollinators have been removed from the loop, those seeding rates and the diversity they're meant to achieve become a ceiling, not a floor.

The Corridor Problem, and a Real Solution

One of the more actionable threads in the podcast conversation was about municipal green space. Think about any mid-sized Iowa town. Pella, Ames, Marshalltown. There are dozens, maybe hundreds of acres of mowed ground within city limits that produce nothing for pollinators. If even a portion of that land were converted to native plantings and connected by corridors to nearby CRP or public land, the needle on pollinator habitat could genuinely move.

The obstacle, as anyone who's dealt with a city council knows, is that the moment twelve homeowners near a prairie patch start getting more mice in their basements, the whole project goes on the chopping block. It's a real challenge. But the ISU study makes the case more clearly than ever that this isn't a nice-to-have. It's load-bearing infrastructure for the ecosystem.

A 2023 peer-reviewed study from the University of Nebraska found that high-diversity prairie restorations and remnant prairies each have different seasonal strengths when it comes to supporting wild bee communities, and that maintaining both types of habitat is necessary to support bee populations throughout the growing season. The upshot is the same: diversity matters, and it needs to be connected.

What You Can Do About It

The most direct response to this research is to plant for pollinators with the prairie in mind, not just the bees. That means prioritizing mixes that span the full bloom sequence from early spring through late fall, so you're not just supporting pollinators in peak summer when it's easy but in the shoulder seasons when forage is thin.

It also means planting where it connects to something. A half-acre pollinator patch surrounded entirely by mowed lawn is better than nothing, but a half-acre that creates a corridor between your neighbor's CRP and the county roadside prairie does significantly more ecological work.

If you're ready to take that step, Hoksey's Native Bee and Butterfly Mix is built specifically for this kind of work: diverse species, locally adapted Iowa ecotypes, and a bloom sequence designed to support the full lifecycle of native pollinators. For backyard-scale projects, the Tall Backyard Pollinator Mix is a great starting point.

The prairie doesn't just need you to plant it. It needs the pollinators to keep it alive once it's in the ground. Turns out that's a reason to plant for pollinators with a lot more urgency than most people have felt.

For more on the ISU study and what it means for reconstruction strategy, check out the Prairie Farm Podcast. And for a deeper look at why Iowa's remnant prairies matter so much to the future of restoration, read this piece on the Hoksey blog.