Sandy Plains
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
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Transition T1A
Continuous, heavy grazing.
More details
Lack of fire. -
Transition T1B
Heavy, continuous grazing.
More details
Lack of fire. -
Transition T1C
Tillage.
More details -
Restoration pathway R2A
Prescribed grazing.
More details
Prescribed fire. -
Transition T2A
Heavy, continuous grazing.
More details
Lack of fire. -
Restoration pathway R3A
Prescribed grazing.
More details
Prescribed fire. -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The Reference State contains three community phases. These phases are historically maintained by a fire return interval of 15 to 20 years (Guyette and others.), herbivory, and adequate recovery periods. High production of perennial grasses and extensive cover allow for increased soil moisture retention, vegetative production, and overall soil quality.
Submodel
Description
This state is dominated by blue grama, and evolved under long-term, heavy grazing pressure. This is a very stable state, resistant to change due to the high tolerance of blue grama to grazing, the development of a shallow root system (also known as a root pan), and subsequent changes in hydrology and nutrient cycling. Extended drought may cause extensive mortality of blue grama. The loss of dominant and sub-dominant functional/structural groups such as tall warm-season grasses, nitrogen fixing legumes, and shrubs reduces the biodiversity and productivity of this site.
Submodel
Description
The Increased Bare Ground State is characterized by low litter, pedestalling, and erosion. Organic matter is greatly reduced and the nutrient, water, and energy cycles are greatly impaired.
The Reference State has been driven beyond the limits of ecological resilience and has crossed a threshold into this state. This designation denotes complete deterioration of the ecological processes.
Submodel
Description
The Tilled State is defined by two separate vegetation communities that are highly variable. They are derived through two distinct management scenarios, and are not successionally related. Infiltration, runoff, and soil erosion vary depending on the vegetation present.
The reference state ecosystem has been driven beyond the limits of ecological resilience and has crossed a threshold into the tillage state. The designation of the tillage state denotes changes in plant community composition and soil structure. This change in plant species and soil structure affects the following ecological processes: hydrologic function, biotic integrity, and soil site stability.
Submodel
Mechanism
Continuous, heavy grazing without adequate recovery opportunity between grazing events contributes to the loss of resilience and result in shifts between states. Lack of fire accelerates this process. The movement from the Reference State to the Shortgrass Dominated State indicates that an ecological threshold has been crossed. This transition involves a major loss of plant diversity resulting in the degradation of biotic integrity.
Mechanism
Long-term heavy, continuous grazing moves this plant community across an ecological threshold to the Increased Bare Ground State. Lack of fire can accelerate this process. Resilience and resistance to disturbance are compromised. Soil site stability, hydrologic function, and biotic integrity are significantly impaired.
Mechanism
Tillage (plowed & abandoned) will cause this state to transition across an ecological threshold to the Tilled State. The resulting change in plant species and soil structure will adversely affect hydrologic function, biotic integrity, and soil site stability. This transition is considered to be non-restorable to the due to irreversible alterations of the soil structure.
Mechanism
Long term grazing management with proper stocking rates and adequate rest to facilitate recovery of the remnant reference plant community species are the management actions required to recover to the reference state. Prescribed fire will accelerate this process.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Prescribed Burning |
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Prescribed Grazing |
Mechanism
Long-term heavy, continuous grazing without adequate recovery opportunity and lack of fire will move the Blue Grama State across an ecological threshold to the Increased Bare Ground State. This transition may take greater than 25 years. Resilience and resistance to disturbance are degraded. Soil site stability, hydrologic function, and biotic integrity significantly impaired.
Mechanism
Long-term prescribed grazing with adequate recovery opportunity between grazing events together with proper stocking are the management actions required to recover to the remnant Reference State. Prescribed fire will accelerate this process.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Prescribed Burning |
|
|
Prescribed Grazing |
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.