Fragipan Upland Flatwoods

Description

These open woodland communities were strongly influenced by fire and seasonal wetness. Herbivory by native (now expatriated) ungulates also played a role. Consequently, drought and fire-tolerant post and blackjack oaks over a ground flora of tallgrass prairie grasses, sedges and wildflowers made up the flatwood community. There are two phases associated with this reference state.

Submodel

Description

Most current areas of Fragipan Upland Flatwoods have experienced fire exclusion for decades. In the absence of fire, ongoing recruitment of trees into the canopy develops a closed canopy, shading out the rich herbaceous ground flora. Black oak and mid-story species increase. Herbaceous cover and diversity greatly diminishes, leaf litter builds up, and more shade-tolerant woodland species persist, such as elm-leaved goldenrod, panic grass and spreading aster. The understory also develops with oak and hickory saplings along with sassafras.

Submodel

Description

Although many of the closed Fragipan Upland Flatwoods are now fenced, most have been heavily grazed by domestic livestock at some point in their history. Grazing decreases the cover and abundance of saplings, shrubs and herbaceous ground flora, opening up the understory. Weedy native shrubs and vines, such as coralberry, gooseberry, poison ivy and Virginia creeper, often flourish after grazing, and exotic species like tall fescue and sericea lespedeza increase in abundance. Poorly managed grazing can cause compaction and denudation of the soil surface, allowing mats of lichens and mosses to flourish. Soil compaction may also further limit height growth of trees. With poorly managed grazing, this can result in an increase in weedy natives such as broom sedge, and exotics such as sericea lespedeza if they are present. Single-tree timber harvesting also occurred, resulting in a high grading of the canopy structure, creating many stands with poor quality trees.

Submodel

Description

Conversion of flatwood ecological sites to planted, non-native grassland species such as tall fescue and red clover has been common occurrence. Clearing is often done by bulldozing. This practice often strips the thin topsoil along with most of the native ground cover plants. Occasionally, clumps of trees will be left in small groves for shade, giving the structural appearance of historic woodlands. However, Fragipan Upland Flatwoods have most often been converted into tall fescue grasslands, adjacent to densely overgrown and grazed woodlots. A return from this condition to a flatwoods state requires enormous cost and management inputs.

Submodel