By Kelly Vowels
When Isaac W. Bernheim purchased the property in 1928, the current location of the Big Prairie was a cornfield. Initially, this area was envisioned as a green swath reminiscent of the European savanna. After the Arboretum was opened in the 1950s, it was mowed and called the Great Lawn. It looked like a golf course and was dominated by fescue with little diversity.
In 1996, Bernheim decided to restore this area as a native grassland. The Big Prairie was created as a habitat for wildlife, supporting many pollinators, birds, mammals, reptiles, and insects. The continued goal is to be a habitat dominated by diverse native plants with more forbs than grass in areas, if possible, and to be a showcase for Kentucky grasslands.
During the last three decades, Bernheim has learned a lot about grassland management. We’ve noticed an uptick in invasive species and some native warm-season grasses that suppressed native grasses and wildflowers. Over the next few years, extensive management will be conducted in The Big Prairie. We are prioritizing removal of woody and invasive species, conducting prescribed fire burns, and assessing the six individual sections for native diversity as a result of our maintenance efforts. This has already occurred in the northern and southern sections of the prairie.
Prescribed fires are beneficial to grasslands by suppressing woody encroachment, stimulating growth of herbaceous plants, and creating gaps for greater native plants. After the burns, extensive management is being conducted to remove invasive species, including Japanese honeysuckle (Lonicera japonica), hairy joint grass (Arthraxon hispidus), and Chinese lespedeza (Lespedeza cuneata). This allows native wildflowers to thrive. In addition, we are actively setting back our thickest stands of big blue-stem Andropogon geradii and Indian grass (Sorghastrum nutans) in an effort to promote native wildflowers. Despite all these efforts, we have noticed the need to add native forbs through seeding.
Hopefully, in the next five years, The Big Prairie will be dominated by native wildflowers with many pollinator species, insects, and animals thriving in the area. There are already signs of the prairie responding to the new management strategy. Milkweed (Asclepias spp.) that are used by monarchs (Danaus plexippus) are popping up in the areas that have been burned and trees removed, as well as many other wildflowers like rattlesnake master (Eryngium yuccifolium) and white false indigo (Baptisia alba). Our efforts in The Big Prairie increase habitat, provide ecosystem services, and spark curiosity in our visitors.
Originally featured in our Summer 2024 issue of the Forest Echo newsletter, Volume 33, No. 3.
