![2520](https://edit.jornada.nmsu.edu/uploads/large/es/pc/2520.jpg)
Deep Sand 23-30" PZ
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
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Transition T1A
Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure
More details -
Transition T1B
Extensive soil disturbance followed by seeding
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Restoration pathway R2A
Adequate rest from defoliation and removal of woody canopy, followed by reintroduction of historic disturbance regimes
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Transition T2A
Extensive soil disturbance followed by seeding
More details -
Restoration pathway R3B
Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure
More details -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
State 1
Grassland State
![2520](https://edit.jornada.nmsu.edu/uploads/large/es/pc/2520.jpg)
![2520](https://edit.jornada.nmsu.edu/uploads/thumb/es/pc/2520.jpg)
![2521](https://edit.jornada.nmsu.edu/uploads/thumb/es/pc/2521.jpg)
Description
The Tallgrass-Oak Complex Community is believed to have been a tallgrass prairie interspersed with a 20 to 25 percent woody canopy of oaks and associated shrubs and vines. Indiangrass, switchgrass, sand bluestem, and purple tridens were characteristic tallgrasses. Midgrasses included sand lovegrass, cane bluestem, sideoats grama and silver bluestem. Post oak and blackjack oak occurred as motts in areas protected from fires. Havard oak, skunkbush sumac, prickly-ash, bumelia, greenbriar, and sand plum were common understory shrubs and vines in the motts. The woody species were apparently kept at low levels because of frequent wildfires and occasional long droughts. Forbs such as prairie clover, yellow Neptune, evening primrose, trailing wildbean, dayflower, and catclaw sensitivebriar thrived in the sandy soils. The Tallgrass/Oak Savannah Community (1.1) produced 3,000 pounds to 4,000 pounds herbage in years with good moisture and as little as 500 to 2,000 pounds in unfavorable years.
The Mixed-grass/Oak Complex Community (1.2) composition of the Mixed-grass/Oak Complex Community on this site varies with time and intensity of grazing. Most reference community species are present but the dominant tallgrasses are being displaced by increases in sand lovegrass, fringed signalgrass, tumble windmillgrass, gummy lovegrass, red lovegrass and weedy forbs. Havard oak, littleleaf sumac, yucca, plum, prickly-ash, greenbriar, poison ivy and sand sagebrush increase in and around the original oak motts. Litter and soil organic matter are lower than in reference condition and some wind erosion might occur during this plant phase. Most reference forbs such as gaura, bundleflower, prairie clover, wildbean, lespedeza, evening primrose, dayflower, senna, catclaw sensitivebriar, and wild buckwheat persist in the Mixed-grass/Oak Complex Community phase. Annual yields range from 1500 to 3500 pounds.
Submodel
Description
The Post Oak/Blackjack Oak Woodland Community is a woodland community composed of post oak and blackjack oak which are usually the dominant overstory but mesquite and western soapberry can also be present. With continued heavy grazing and no brush control, the trees and shrubs can approach 85 to 90 percent or more ground cover. A dense understory of shrubs often forms to crowd out herbaceous species. Only shade-tolerant species exist in the dense woodland areas. Shortgrasses and low seral stage annual and perennial forbs occupy the woody plant interspaces. Grasses and forbs make up 30 percent or less of the annual herbage production.
Submodel
Description
The Converted Land State is cropped annually with forage, fiber, grain, or wildlife food plots. This state can also be cleared, plowed, and planted into native or exotic pasture grass species. The community may be left abandoned and let ‘go back’ to the native species. Various stages of secondary succession prevail until the oak woodland forms.
Submodel
Mechanism
With continued overgrazing by livestock and no brush management, however, the shrub component of the grassland portion increases and oak motts grow in size and plant density. Once this threshold is reached grazing management and prescribed burning will generally not be effective in maintaining the community. More costly, accelerated brush control practices will be required to reverse the trend toward dense woodland.
Mechanism
brush removal practices, crop cultivation, plowing, pasture planting, pest management and nutrient management, the Grassland State can be converted into the Converted Land State.
Mechanism
Major high cost and high energy accelerating practices are required to restore the Post Oak/Blackjack Oak Woodland Community (2.1) back to a grassland state. Generally, brush management practices such as aerial herbicide application, along with other conservation practices such as range planting, grazing deferment, prescribed grazing and prescribed burning are necessary to return the shrubland state the grassland state.
Relevant conservation practices
Practice | External resources |
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Brush Management |
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Prescribed Burning |
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Range Planting |
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Prescribed Grazing |
Mechanism
With brush removal practices, crop cultivation, plowing, pasture planting, pest management and nutrient management, the Woodland State can be converted into the Converted Land State.
Model keys
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Ecological sites
Major Land Resource Areas
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.