State 1
Oak Savannah - Reference

This is the reference state for the Sandy Loam ecological site. It represents the historic range of variability in the plant communities with the periodic disturbance of fire and grazing. It is a mosaic of herbaceous plants oak species and woody understory vines and shrubs.

The dominant trees are post oak and black jack oak with a mixture of tall and midgrasses, forbs and shrubs in the understory and canopy interspaces. Dominant herbaceous plants include little bluestem, big bluestem, Indiangrass, switchgrass, beaked panicum, purpletop tridens, sand lovegrass, and wildryes. Other grasses include dropseeds, sedges, and Scribner's panicum. Forbs include Sunflowers, Englemann daisy, tickclover, lespedezas, wildbeans, yellow Neptune, echinacea, and guara. Other woody plants include elms, greenbriar, plums, grapes, hawthorn, American beautyberry, coralberry, and Carolina snailseed. These woody species will increase in ground cover with the absence of fire.

Woody canopy in the reference state is complex with some areas having dense oak canopy mixed with multiple prairie openings. For planning and management purposes, the average woody canopy in reference condition can be described as less than 40%.

The Sandy Loam site is estimated to produce between 3,500 to 6,000 pounds of vegetative production per year in reference condition.

Tallgrasses = Midgrasses greater than Trees greater than Forbs & Shrubs

Community 1.1

State 2
Closed Canopy Woodland

Figure 10. Gasil soils. Hill County, TX

This state represents the shift to a woody dominated plant community with woody canopy exceeding 60 percent. Trees and shrubs dominate the ecological processes on the site and the herbaceous grasses and forbs are limited to shade-tolerant species. There is an abundance of leaf litter build up which further limits herbaceous plant germination and production.

State 3
Converted

Figure 11. Gasil soils. Hill County, TX

This state represents a change in land use from rangeland to pastureland. The soil structure and biology has been altered and the site is dominated by introduced species. Management of introduced forages requires more inputs than native grasses. Careful consideration should be taken prior to planting to ensure the result meets the desired use. Ratings for forage yields can be found under the Non-irrigated Crop Yield section in Web Soil Survey. As with any fertility management program, current soil tests should be taken before planting and subsequent fertilization of introduced pastures.

The most common forage species on these sites include bermudagrass and Old World bluestems(eg. KR bluestem).

Without brush management, woody species such as mesquite, juniper, elm, or honey locust may invade these sites.

There may be opportunities to plant native grass species on these sites to restore the reference plant communities. The success of this type of restoration is highly variable and depends on the remaining soil resources and past management. This type of endeavor often requires site specific planning and evaluation. However, the species described in the reference state are a good resource for initial planning of any restoration project.

State 4
Severely Eroded

Cultivation of these sites may lead to severe erosion. Depending on slope and farming practices, a significant amount of the A horizon may be eroded from the soil profile. This soil loss results in the transition to the Severely Eroded State.

Transition T1A
State 1 to 2

Without periodic fire or brush management the reference state will transition to the Closed Canopy Woodland state. Woody species will continue to increase and lead to mesophication of the plant community with increased woody canopy and an increase in shade-tolerant species.

Transition T1B
State 1 to 3

Most of these sites were cultivated for crop production during the settlement of the area. Many of them have been planted to monocultures of introduced forage grasses in recent years. When these sites are cultivated, the soil properties are significantly altered from the reference state. Soil structure, hydrology and biology have been impacted and the site is transitioned to the Converted State.

Transition T1C
State 1 to 4

Cultivation of these sites may lead to severe erosion. Depending on slope and farming practices, a significant amount of the A horizon may be eroded from the soil profile. This soil loss results in the transition to the Severely Eroded State.

Restoration pathway R2A
State 2 to 1

At this point it will take significant inputs to remove woody species and restore the Savannah State. This will require some selective thinning of woody species and the re-introduction of fire to the ecosystem. This process may take 5 years or more depending on woody canopy and past management. Grazing management including some deferment will be required to help reestablish the herbaceous plant community.