Tallgrass prairie is one of the most threatened ecosystems in the world, and yet there is hope for the future of the ecosystem that defines Illinois, aka the prairie state. Tallgrass prairie is an open grassland ecosystem characterized by abundant tall grasses like big bluestem, Indian grass, and little bluestem, with hundreds of species of wildflowers. In Illinois, tallgrass prairie evolved with regular fire set by Indigenous people and grazing from large herbivores like American bison, commonly referred to as buffalo. As such, the tallgrass prairie is known as a disturbance-dependent ecosystem, where plants and animals need intermittent fire and grazing events to thrive.
Over the past 200 years, the Illinois landscape has transformed from large expanses of open grassland and savanna to one that is predominantly intense row-crop agriculture and urban/suburban development. Today, only a few thousand acres of tallgrass prairie habitat remain. Many people across Illinois continue to care deeply for the tallgrass prairie, and their efforts across many decades have launched ecosystem restoration projects throughout the state.
At The Nature Conservancy’s Nachusa Grasslands in northern Illinois, volunteers and scientists have been working since the mid-1980s to restore a small landscape of tallgrass prairie near Dixon. The goals of the project are rooted in re-establishing highly diverse native plant and animal communities, as well as the ecological connections that supported the prairie throughout history and will carry it into the future.
Ecosystem restoration is about taking a holistic habitat approach. Restoration work at Nachusa Grasslands begins as seeds collected across the growing season are planted into former agricultural lands to re-establish native plant communities. These plants attract and host thousands of insects, including more than 270 bee species. Birds, bats, and small rodents feast on these insects. Other mammals consume the plants directly: rabbits, voles, deer, and even the American bison. Predators like coyotes, raptors, bobcats, and foxes feed on smaller mammals and reptiles. Our goal is to re-establish open grassland and savanna habitat and reinstate biological interactions to set this ecosystem up for success today and for generations to come.
To maintain healthy connections among plants and animals across thousands of acres of land, the prairie benefits from prescribed fire and grazing encouraged by people. Nachusa Grasslands has relied on prescribed fire as an important management tool since it began. As the project grew, the dream to reintroduce the American bison became feasible. In 2014, a small herd of was reintroduced to Nachusa Grasslands. Over the past 10 years, the herd has grown to 100 animals grazing on 1,500 acres. And they’re making their mark on the prairie!
With the reintroduction of the bison, researchers have been collecting data to learn how the large herbivores influence plants, animals, and their interactions. So far, plant community diversity has not shifted with grazing. Bison do graze certain areas and plants, maintain a shorter, more open grassland structure, but the members of that plant community have not shifted. In contrast, their grazing is impacting animal communities in some fascinating ways. Bison presence has increased the abundance of dung beetles. Grazing is also shifting the diets and foraging behavior of ground beetles, mice, and voles.
Management interactions between prescribed fire and grazing are also becoming apparent. Recent work shows fire and grazing can interact to support grassland bird habitat. Henslow’s sparrows return to recently burned units more quickly in the presence of bison. Grazing patterns can lead to patchier fires, which create a mosaic of open and more dense grassland structure. Research at Nachusa Grasslands continues, entering the tenth year of data collection. We continue learning from all the interacting plants, animals, and landscape!
This blog post was written by Elizabeth Bach, Research Scientist at Nachusa Grasslands, The Nature Conservancy
About Everyday Environment
Everyday Environment is a series of blogs, podcasts, webinars, and videos exploring the intricate web of connections that tie us to the natural world. Want to listen to us chat about this topic? Check out the podcast episode on this topic to hear more from the Everyday Environment team about wildlife resources.
Was there something about this blog's topic we didn’t cover? See something cool in nature? Let us know! Send us your question or share your everyday nature observation with us at go.illinois.edu/EEconnect, and we may share it in a future blog or podcast.
Listen to the Podcast Get the Everyday Environment Newsletter Connect with Us