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.
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.
The overall aspect of this community phase is grasses and shrubs with young pinyon and juniper. The herbaceous understory has a mix of grasses and forbs.
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.
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.
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.
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
Briefcase
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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.
) 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.
