Very Shallow
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
- Transition T1A More details
- Restoration pathway R2A More details
-
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The Reference State represents the best estimate of the natural range of variability that dominated the dynamics of the Very Shallow ecological site prior to European settlement. This state is a mix of cool- and warm season grasses. In pre-European times, the primary disturbance mechanisms included occasional fire and grazing by large herding ungulates. Timing of fires and grazing coupled with weather events dictated the dynamics that occurred within the natural range of variability. Taller cool- and warm-season grasses would have declined and a corresponding increase in short statured grass and grass-like species would have occurred. Today, a similar state can be found on areas that are properly managed with grazing and prescribed burning and sometimes on areas receiving occasional short periods of rest. The Reference State is susceptible to invasion of non-native cool-season grasses and the potential encroachment of conifers from adjacent sites.
Submodel
Description
The Native/Invaded State is dominated by native cool- and warm-season grasses, and subdominant non-native cool-season grasses. It can be found on areas that are properly managed with grazing and on areas receiving occasional short periods of rest. If the native cool-season grasses decline a corresponding increase of non-native cool-season grasses can occur. The non-native cool-season grasses will include cheatgrass, field brome, and Kentucky bluegrass.
Submodel
Mechanism
Invasion of non-native cool-season grasses and extended periods of drought will cause a transition from the Reference State (1.0) to the Native/Invaded State (2.0).
Mechanism
Long-term prescribed grazing (moderate stocking levels coupled with adequate recovery periods, or other grazing systems intended to treat specific species dominance, or periodic light to moderate stocking levels possibly including periodic rest) coupled with a return to more normal precipitation cycles may lead the Native/Invaded State (2.0) over a threshold to the Reference State (1.0). This will likely take a long period of time, possibly up to 10 years or more, and recovery may not be attainable.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Prescribed Grazing |
Model keys
Briefcase
Add ecological sites and Major Land Resource Areas to your briefcase by clicking on the briefcase (
) icon wherever it occurs. Drag and drop items to reorder. Cookies are used to store briefcase items between browsing sessions. Because of this, the number of items that can be added to your briefcase is limited, and briefcase items added on one device and browser cannot be accessed from another device or browser. Users who do not wish to place cookies on their devices should not use the briefcase tool. Briefcase cookies serve no other purpose than described here and are deleted whenever browsing history is cleared.
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.