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Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
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Transition T1A
Excessive grazing.
More details
Lack of fire. -
Transition T1B
Mechanical tillage.
More details -
Restoration pathway R2A
Prescribed grazing.
More details
Prescribed fire. -
Transition T2A
Excessive grazing.
More details
Lack of fire. -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The Reference State is characterized by three plant community phases. These plant communities, and the various successional stages between them, represent the natural range of variability within the Reference State.
Submodel
Description
An ecological threshold has been crossed and a significant amount of production and diversity has been lost when compared to the Reference State. Significant biotic and edaphic (soil characteristics) changes have negatively impacted energy flow and nutrient and hydrologic cycles.
This is a very stable state, resistant to change due to the high tolerance of blue grama and buffalograss to grazing, the development of a shallow root system (aka root-pan), and subsequent changes in hydrology and nutrient cycling. The loss of functional/structural groups such as cool-season bunchgrasses, forbs, and shrubs reduces the biodiversity and productivity of this site.
Submodel
Description
An ecological threshold has been crossed. Litter levels are extremely low due to reduced production. Increased bare ground can cause erosion, off-site runoff, and deposition when rainfall events are intense. The nutrient cycle, water cycle, and overall energy flow are greatly impaired. Organic matter and carbon reserves are greatly reduced.
Submodel
Description
The Tilled State is the result of the site being tilled (farmed). An ecological threshold has been crossed due to complete removal of native vegetation and soil tillage. Physical, chemical, and biological soil properties have been dramatically altered.
Submodel
Mechanism
Excessive grazing and lack of fire shifts this plant community across an ecological threshold to the Warm-Season Shortgrass State.
Mechanism
Tillage causes an immediate transition across an ecological threshold to the Tilled State. This transition can occur from any plant community and it is irreversible.
Mechanism
Long-term prescribed grazing that incorporates adequate recovery periods, proper stocking, and prescribed fire restore this state to the Reference State, assuming an adequate seed or vegetative source is available. This restoration may require substantial time depending on the proximity to seed source and remnant species present.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Prescribed Burning |
|
|
Prescribed Grazing |
Mechanism
Long-term, heavy continuous grazing without adequate recovery periods and lack of fire cause a shift across an ecological threshold to the Increase Bare Ground State. Erosion, loss of organic matter and carbon reserves, and flooding are concerns. Non-native exotic plants such as field bindweed and knapweeds are likely to invade.
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.