Fragic Till Plain Woodland

Description

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

Submodel

Description

Most current areas of Fragic Till Plain Woodlands 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. This results in the formation of Post Oak – Hickory / Oak & Hickory Saplings / Goldenrod forests. Black oak and midstory species may increase. Herbaceous cover and diversity greatly diminishes, leaf litter builds up, and more shade-tolerant woodland species persist, such as goldenrods (Solidago spp.), panic grasses (Dichanthelium spp.) and asters (Symphyotrichum spp.). The understory also develops with oak and hickory saplings along with sassafras and black cherry.

Many of the closed Fragic Till Plain Woodlands 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 (Symphoricarpos orbiculatus Moench), gooseberry (Ribes spp.), poison ivy (Toxicodendron radicans (L.) Kuntze ) and Virginia creeper (Parthenocissus quinquefolia (L.) Planch.), often flourish after grazing, and exotic species like tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. Cons.) and sericea lespedeza (Lespedeza cuneata (Dum. Cours.) G. Don) increase in abundance.

Poorly managed grazing can cause compaction and denudation of the soil surface. 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 sedges (Carex spp.), and exotics such as sericea lespedeza (Lespedeza cuneata (Dum. Cours.) G. Don) 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.

Description

Conversion of other states to non-native cool season species such as tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.), red top (Agrostis stolonifera L.) and white clover (Trifolium repens L.) has been common in the Illinois Central Claypan area.

Description

This is an occasional state that exists with intensive cropping of corn (Zea mays L.), soybeans (Glycine max (L.) Merr.), and winter wheat (Triticum aestivum L.) occurring. Water management activites are needed to maximize yields. Some conversion to cool season grassland occurs for a limited period of time before transitioning back to cropland.