Open Woodlands at Chickamauga Battlefield Park

I visited Chickamauga National Battlefield Park last week for the first time in many years. We were in northwest Georgia to see my mother-in-law for a couple of days. She lives in the Chickamauga Valley, and I’m familiar with the natural history of the region. Next week, I’m going to cover the history of the battle itself along with the horrors of war (for my annual Halloween blog post), but this week I want to focus on the natural history of the park. The landscape consists of large, mowed fields bordered by open woodlands.

Turkey and deer thrive in this type of environment.

An open woodland is defined as an environment with 50%-75% canopy cover. A forest is defined as an environment with >75% canopy cover. I estimate this is woodland, not forest.

Some of the trees here grow quite large.

Men were shooting, stabbing, and clubbing each other to death at this site 158 years ago.

An open woodland is defined as an area with 50%-75% tree canopy cover, while a forest is considered an area with >75% tree canopy cover. A woodland has widely spaced trees that allow enough light for grass, and shade intolerant shrubs and saplings to grow. Species of trees I found growing at Chickamauga Battlefield Park included white oak, black oak, northern red oak, scarlet oak, willow oak, black walnut, hickory, southern sugar maple, box elder, tulip, ash, Kentucky coffee tree, cedar, shortleaf pine, and loblolly pine. Botanists believe chestnut was formerly a co-dominant tree here on soils underlain by dolomite, but chestnut blight wiped them out a century ago. Many of the trees in the park now are over 100 years old. Shallow well-drained acidic soils predominate, and they are underlain by dolomite, limestone, shale, and sandstone.

Cedar trees are not fire tolerant. Open woodlands at this site are maintained by mowing and a high population of foraging deer, not fire.

This is either field thistle (Cirsium discolor) a native of North America or bull thistle (C. vulgaris), a native of Europe that has colonized North America. Enough sun reaches the woodland floor that shade-intolerant species can grow. Thistles attract many species of bees and butterflies and seed-eating birds.

Open woodland has probably been the most common environment on this site for millions of years. During the Pleistocene, megafauna foraging, ice storms, and windy conditions likely prevented the tree canopy from getting thick. More recently, Indians set fire to the woods frequently, thus keeping tree canopy open with thermal pruning. Now, I hypothesize a high density of white-tailed deer is keeping this woodland open. There is no hunting inside the park, though it occurs in adjacent areas. I suspect herds of deer find refuge here, and they thin out saplings with their hungry appetites. This habitat is ideal for deer and turkey, and I saw both while driving through the park. Road-killed coyotes are a common site on nearby roads. Fox, skunk, raccoon, possum, squirrel, woodchuck, and rabbit can be found in the park too.

See also: https://markgelbart.wordpress.com/2021/05/20/deer-herbivory-alters-plant-and-bird-species-composition/

Reference:

Wharton, Charles

The Natural Environments of Georgia

Georgia Department of Natural Resources 1978