by Alan Abbott
One of the defining characteristics of the Bluegrass and Pennyroyal Plateau regions is the presence of small, rocky glades. Broadly speaking, a glade is any clearing in a forest. But in our part of the country, it tends to refer to areas with a shallow soil and a limestone bedrock, usually on south- or west-facing slopes. Without trees shading everything out, a rich layer of grasses and forbs emerges. As islands of grassland within larger forested areas, they tend to have high rates of endemism, or plants found only within one, relatively small area. Some plants can be found only in a few counties (like Kentucky gladecress, Leavenworthia exigua var. laciniata) or a narrow region, like the Interior Low Plateau, which runs from northern Alabama, through central Tennessee and Kentucky and into south-central Indiana.
Their isolation means that glades separated by only a few miles can have surprisingly different plant communities. In Harrison County, Indiana, which has similar shallow soils and limestone bedrock as Kentucky’s Bluegrass Region, one glade may have hundreds of Echinacea and a similar one walking distance away won’t have any.
There are a number of opportunities to see limestone glades in the greater Louisville area this year. As part of the Botany Blitz, KNPS members met at Pine Creek Barrens in Shepardsville to see Kentucky gladecress, as well as the more common spring ephemerals in the woods that surrounded the grasslands.
In Indiana, the Nature Conservancy had a Glade Appreciation Day on May 7th in Harrison County. Information for many of the glades of the area can be found here: Harrison County Glades | The Nature Conservancy
KNPS will be providing a tour of some Harrison County glades in July, when the wildflower show should be near its peak. More information to follow. The glades are about 45 minutes northwest of Louisville.
We’ll also be offering another tour of Pine Creek Barrens in September to see the Asters and Blazing Stars.