Savannah Breaks

Description

In reference condition, this site is a fire-driven climax of Oak savannah with a tall grass understory. Average woody canopy cover is below 60 percent. Surface rock from cobbles to boulders may be up to 25 percent. The composition by functional group production consists of 40 percent tall grasses, 25 percent mid grasses, and 10 percent forbs and legumes. Total average herbaceous production can range from 500 to 1,800 pounds per acre. Some juniper may occur depending upon the last fire or in areas protected from fire due to rock outcrops. Species composition can vary somewhat depending on the present soil resources and depth to bedrock.

Due to the slope and amount of surface rock, these sites are rarely grazed by domestic livestock. In some areas, the sites themselves are uses as natural barriers between pastures eliminating the need of traditional fences. There is some potential use by goats if they are adapted to utilizing such landscapes. However, numerous wildlife species may utilize these sites for bedding, foraging, and escape cover.

Characteristics and indicators

Post Oak & Blackjack Oak with understory of native tallgrass species.
<60% woody canopy
2-5 year fire return

Resilience management

In the absence of fire, mid-story woody species including elm, hackberry, and eastern redcedar, and greenbriar will begin to encroach into the sites and shade out understory species. This creates a risk of transition to the Woody Invasion State.

Submodel

Description

The description for this plant community is derived from analysis of limited field data and professional consensus of range trained individuals.

This state is the result of the removal of fire from the ecosystem. Without fire, some fire-intolerant woody species have been able to grow and reproduce unchecked. This has resulted in an increase in canopy coverage and hindered the growth of the herbaceous understory of the reference state.

The understory woody browse, forbs, and legumes cannot persist as the woody mid-story takes over. Thus much of the wild life habitat value declines as the site transitions to this state.

Much of the hydrologic cycle has changed as the functional plants are the woody overstory. Some rainfall is trapped in the foliage of the overstory and evaporates but some also reaches the soil via stem flow. Without the herbaceous understory, the sight may be prone to increased runoff from overland flow.

Characteristics and indicators

Oak/Hickory Woodland with Hackberry, Elm, and Juniper encroachment.
Shade tolerant herbaceous plants.
>60% woody canopy
>5 year fire return

Resilience management

Tools that restore the energy flow back to these plants and restore the hydrologic cycle include an integrated approach using brush management and fire. It is possible to restore this plant community to something similar to the reference plant community but may be very difficult depending on remnant seedstocks and time since fire.