Fragipan Upland Woodland

Description

These open woodland reference communities were strongly influenced by fire. Herbivory by native 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 post oak - blackjack oak/little bluestem woodland. There are two phases associated with this reference state.

Submodel

Description

Most current areas of Fragipan Upland 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 – Black Oak – Black Hickory / Oak – Hickory Saplings / Goldenrod woodland. Black oak and midstory 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 and black cherry.

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Description

Although many of the closed Fragipan Upland Woodlands 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 buckbrush, gooseberry, poison ivy and Virginia creeper, often flourish after grazing, and exotic species like 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 poorly formed trees.

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Description

The Pine Plantation state results from clearing the oak woodlands and planting shortleaf pine. Shortleaf pine grows well on less-productive sites, so the practice was common during reforestation of the Ozarks. The plantations are typically dense, mature stands of shortleaf pine with deep leaf litter and little understory or ground flora vegetation. A return from this condition to an oak woodland state requires enormous cost and management inputs.

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Description

Conversion of woodland 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 Woodlands have most often been converted into wide, open fescue grasslands, adjacent to densely overgrown and grazed woodlots. A return from this condition to a woodland state requires enormous cost and management inputs.

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Description

Although this state is currently uncommon, Fragipan Upland Woodlands have the potential to support controlled grazing while maintaining a near-reference composition and structure. Short periods of rotational grazing, especially during the hot, dry summer season, along with thinning and prescribed fire, has the potential to create an open, diverse woodland with abundant native forage. Controlled grazing may emulate historical grazing by native herbivores and create a structural diversity in the ground flora that may be beneficial to ground-nesting birds.

The Managed Silvopasture state has an open, two-tiered structure of black oak and shortleaf pine over native grasses and forbs. Canopy height is typically 60 to 70 feet, with canopy closure of 40 to 80 percent. Native grasses include little bluestem, big bluestem and Indiangrass.

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