Natural Resources
Conservation Service
SHALLOW NORTH SLOPE 9-11 P.Z.
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
- Transition T1a More details
- Transition T1b More details
- Transition T2 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 is representative of the natural range of variability under pristine conditions. The reference state is dominated by black sagebrush with a significant amount of perennial bunchgrasses. Long-term plant community phase changes are primarily driven by periodic wildfire, insect attack or long-term drought. Plant community dynamics are driven by interactions between climatic patterns and disturbance regimes.
Submodel
Description
The invaded state is characterized by the presence of non-native species. Introduced annuals, such as red brome and redstem filaree, have invaded the reference plant community. These non-natives annuals are highly flammable and promote wildfires where fires historically have been infrequent. A biotic threshold is crossed, with the introduction of non-native annuals that are difficult to remove from the system and have the potential to significantly alter disturbance regimes from their historic range of variation. The presence of non-natives has reduced the ecological resilience of the site.
Submodel
Description
The tree state is characterized by the invasion of pinyon and juniper and tree cover greater than 20 percent. Lack of fire, drought and insect/disease attack allows seedlings and saplings to infill and eventually dominate, changing the ecological dynamics of the site. Non-native annuals may or may not be present in the understory. This state experiences reduced infiltration and increased runoff during precipitation events, diminishing soil moisture. Feedbacks contributing to the stability of this state include reduced understory vegetation resulting from decreased soil moisture and overstory shading.
Submodel
Mechanism
Introduction of non-native species due to a combination of factors including: 1) surface disturbance, 2) changes in the kinds of animals and their grazing patterns, 3) drought and/or 4) changes in fire history.
Mechanism
Continued lack of disturbance. Encroachment and establishment of pinyon and juniper. Tree canopy is greater than 20 percent and bare ground is increasing.
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.
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