What is a prairie? Some might say it's the plants or the soils; others might argue it's the wildlife: pollinators like bees and butterflies, or the birds that nest, forage, and sing there.
We at the Aldo Leopold Foundation are trying to understand the kinds of landscapes we have by conducting ecological surveys that study all of these factors. This work is part of a multi-year project with OneEnergy, an energy company that works to convert target sites to prairie while integrating solar panels into their restoration plans. As the monitoring fellow here at the Aldo Leopold Foundation (ALF), I was tasked with conducting a myriad of surveys to quantify the bumblebees, monarch butterflies, birds, and vegetation of potential prairie restoration sites, with the eventual goal of understanding how wildlife might interact with solar panels. At this stage, though, the surveys are important to establish a baseline that future observations can be compared to.
Three sites were surveyed: two agricultural fields currently in production outside of the Leopold-Pines Conservation Area (LPCA), one corn field and one soybean field; and an early-stage restored prairie, named "Ollie's Prairie," here on LPCA property. As a former agricultural plot, Ollie's Prairie serves as a benchmark for the other crop fields after they are converted to native grassland habitat.
As expected, there were zero bumblebees or monarch butterflies found in the agricultural fields. Without any flowering plants at these sites, there was nothing to attract these pollinators. However, we did find bumblebees and monarchs in Ollie's Prairie, utilizing the nectar resources available to them from a diverse prairie planting. The deliberate planting of various milkweed species in Ollie's attracted monarchs, for whom milkweed is a critical food source during their life cycle. We saw lower than expected numbers of bumblebees in the prairie. This was likely due to the fact that it had just been mown. Mowing is a key management strategy in the early years of establishing a prairie to reduce weedy propagation and increase native grass presence; however, in the short term, cutting off the flowering heads of plants reduces food for bumblebees. There were some smaller blooming plants that benefited from taller neighbors no longer blocking the sunlight, which provided resources for the bees observed during the survey period.
While birds were observed at each of the three survey sites, the particular species and relative abundance varied between Ollie's and the agricultural fields, with more grassland birds in Ollie's and fewer in the farm fields. Grassland birds spotted in the farm fields were most likely to be adaptable generalists, that is, species that can survive in a wide range of habitats, such as the Red-winged Blackbird. However, species like the Dickcissel need specific habitat structures in order to thrive. As you can imagine, a corn or soybean field might not offer the same resources or structure that a prairie does, so more specialist species were less likely to be found in the agricultural sites.
Unfortunately, grassland bird populations are severely in decline across the globe, largely due to loss of suitable habitats. Southern Wisconsin used to be made up of grassland ecosystems like prairie and savanna until European settlement; the suppression of frequent fire and the conversion of these landscapes to agricultural use led to their widespread erasure from this area. The Aldo Leopold Foundation focuses on restoring prairies and savannas in its stewardship work. When we observe species like the Dickcissel in our restored sites, it indicates the quality of the restored habitat, and that certain management practices have been met.
Lastly, I like to think of vegetation as the glue that holds an ecosystem together. The plants making up a given habitat determine whether birds can nest or forage there and whether bumblebees and monarch butterflies can find nectar. We can observe the significance of vegetation by comparing these sites: we found little to no grassland birds, bumblebees, or monarchs in the agricultural fields, and found more of these fauna in Ollie's Prairie. The crop fields, generally, have only one species of plant with a few agricultural weeds. The restored prairie, on the other hand, has a diverse spread of native plants. This heterogeneity supports the structure needed by grassland bird species and also offers the nectar and pollen resources that bumblebees and monarchs require.
Ollie's is a fairly recent prairie planting, yet the presence of wildlife there shows that if we plant it, they will come, and we are sure to observe even more wildlife in the coming years. Once the surveyed crop fields are converted to prairie, they too will become host to these amazing organisms. In addition to the ecological benefit, these plots will also provide an economic benefit after the OneEnergy solar panel installation.
To return to the question posed at the beginning: what is a prairie? All of those responses are true: soils, plants, insects, and birds. A prairie is a culmination of all parts of the whole, abiotic and biotic, relying upon each other to support and cultivate a unique environment that lives and breathes together.
The Aldo Leopold Foundation was founded in 1982 with a mission to foster the land ethic through the legacy of Aldo Leopold, awakening an ecological conscience in people throughout the world.
