Pinyon-Utah juniper/skunkbush sumac
Scenario model
Current ecosystem state
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Management practices/drivers
Select a transition or restoration pathway
- Transition T1A More details
- Transition T1B More details
- Restoration pathway R2A More details
- Restoration pathway R3A 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 variability and dynamics of this site that occurred naturally. This state includes the dominant biotic communities that would have occurred on this ecological site prior to European Settlement. The dominant aspect of this site is Pinyon and one-seed Juniper with an understory of shrubs and associated grasses. Fluctuations in species compositions and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors. The primary disturbance mechanisms for this site in reference condition include drought, insects, and infrequent fire. The higher in elevation and higher precipitation area would burn more frequently as they would have more fine fuels in the understory. The timing of drought, and fire, coupled with surface disturbance can dictate whether the community can stay within the reference state or if the community transitions into another state.
Submodel
Description
The overall aspect of this community phase is grasses and shrubs with scattered pinyon and juniper. The herbaceous understory has a mix of grasses and forbs.
Submodel
Mechanism
This pathway is very unlikely, but can occur when a fire is able to move through the community on a large scale basis. Two situations can make this occur: 1) a fire can carry in the understory after several wet years allow fine fuels to accumulate, or 2) as the woodland approaches the later stages of development where canopies become dense and crown sizes have increased, and thus community phase becomes susceptible to crown fires. Vegetation treatments can be used to mimic this pathway.
Mechanism
Small scale fire (i.e. smaller lightning strike fires), vegetation treatments that removes trees (i.e. tree harvesting), and/or climatic periods that do not favor pinyon and juniper regeneration.
Mechanism
This pathway occurs when the climate favors the establishment and growth of trees. Reduced influence from fire, insects, and drought could cause the tree canopy to close, effectively reducing the herbaceous understory thus facilitating the transition. More energy is taken-up and stored in the trees as the length between fires increase (lack of fire). Droughts are more frequent and are longer in length. Improper grazing and or increase surface disturbance combined with periods of drought can facilitate this transition.
Mechanism
This pathway occurs when the climate favors the establishment and growth of mature trees. More energy is taken-up and stored in the trees as the length between fires and droughts increase. Time without disturbance and natural succession will cause this pathway.
Model keys
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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.