The Ingleside Oak. Credit: Tom Kimmerer.
The first European explorers of the Bluegrass found extensive woodland pastures of open-grown trees shading grasses and giant cane, covering many square miles, mixed with denser forests and stands of pure cane along the creeks. This astonishing landscape was unlike anything the explorers, accustomed to slow travel through dense forests, had ever seen. News of this fine land well suited to farming quickly brought settlers.
In 1779, a party of travelers arrived after a long journey from the east. I like to think that they came up the buffalo trace and passed the Ingleside Oak, but whatever route they took, they set up camp on a spring-fed stream called Town Branch. About a mile north of the Ingleside Oak, a young Virginian named Josiah Collins felled a huge bur oak. Collins and his companions built a small blockhouse from the oak, and then a group of small cabins from oak, ash and walnut. This was the beginning of Lexington.
The new town grew quickly as farmers settled in with their cattle and sheep. They were able to graze livestock without the immense labor of clearing forests. Some of the trees were felled for buildings, but many were left to shade the pastures. The giant cane and native grasses were quickly grazed down and replaced by non-native grasses. Ironically, the most important grass brought by farmers is now known as Kentucky Bluegrass, although it was originally from Europe or Asia.
What explains the presence of woodland pastures of open-grown trees, grass and cane? This landscape exists in only two places in North America, the Bluegrass of Kentucky and the Nashville Basin of Tennessee. E. Lucy Braun, the renowned forest ecologist, called this “the most anomalous vegetation in North America.”
Woodland pastures do exist elsewhere in the world, in England, Russia and especially in Romania, where they have been maintained by traditional livestock agriculture. Thanks to the work of scientists, such as Oliver Rackham, Frans Vera and Tibor Hartel, we know a lot about the history of European woodland pastures. The most important thing we know about them is that they were originally created and maintained by vast herds of grazing mammals, including wisent (European bison), aurochs (ancestral cattle) and horses. Early farmers took advantage of this habitat, driving off or domesticating the native mammals and raising livestock and crops.
This appears to be what happened in the Bluegrass. Although we think of American bison as western animals, there were herds numbering in the thousands in the Bluegrass, grazing on the rich grass and cane, and wandering along the buffalo traces in search of water. The intermittent grazing of bison, feeding intensely in one area and then leaving for long periods, allowed the woodland pasture habitat to flourish, just as it did in Europe thousands of years earlier.
Drought has always played a role in the Bluegrass. Although our soils are rich and thick, they lie atop deep Ordovician limestone with fractures, caves and sinkholes. Our rainfall is abundant but percolates quickly through the limestone. Most of our creeks dry up soon after a rain. A prolonged period of drought from around the year 600 to 1100, known from tree rings, may have brought bison to the region from the more drought-stricken west and established the first woodland pastures. A series of droughts in the 18th century just before Europeans arrived coincides with the age of many of our ancient trees. One of the characteristics of our trees is that they are deeply rooted into the fractured limestone, with access to water that is not available to other plants. The woodland pastures of the Bluegrass were created and maintained by drought and bison, not by humans.