GRAVELLY PEDIMENT 3-5 P.Z.
Scenario model
Current ecosystem state
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Management practices/drivers
Select a transition or restoration pathway
- Transition 1a More details
- Transition 1b More details
- Transition 2 More details
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No transition or restoration pathway between the selected states has been described
Target ecosystem state
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Description
This state represents the natural range of variability under pristine conditions and is dominated by drought tolerant native shrubs. Primary natural disturbance mechanisms affecting this ecological site are long-term drought and insect attack. Historically, wildfire was infrequent and patchy due to low fuel loading, resulting in long-lived stable plant communities. Timing of disturbance combined with weather events determines plant community dynamics.
Submodel
Description
Introduced annuals such as red brome, schismus and redstem stork's bill have invaded the reference plant community and have become a dominant component of the herbaceous cover. This invasion of non-natives is attributed to a combination of factors including: 1) surface disturbances, 2) changes in the kinds of animals and their grazing patterns, 3) drought, and 4) changes in fire history. These non-natives annuals are highly flammable and promote wildfires where fires historically have been infrequent.
ATHY and AMDU would persist after invasion by non-native annuals, but other species may be unsuccessful in competing with the non-natives and could be removed from the system.A biotic threshold has been crossed, with the introduction of non-natives that cannot be removed from the system. The presence of non-natives has reduced the ecological resilience of the site. Following a disturbance this state relies on the availability of an offsite seed source. These non-natives have the potential to significantly alter disturbance regimes from their historic range or variability.
Submodel
Description
The Eroded State is characterized by severely decreased soil stabilization and increased rills and gullies. A biotic threshold has been crossed, with the loss of long-lived native vegetation and microbiotic soil crust leading to active soil erosion. This state is characterized by a new ecological equilibrium, one that includes reduced nutrient cycling and infiltration.
Submodel
Mechanism
Introduction of non-native species through anthropogenic disturbances, including OHV use, dry land farming, grazing, linear corridors, mining, military training operations, and settlements.
Mechanism
Anthropogenic disturbance removes vegetation and soil crust leading to increased erosion.
Model keys
Briefcase
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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.