Mountain Clay (slender wheatgrass)
Scenario model
Current ecosystem state
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Management practices/drivers
Select a transition or restoration pathway
- Transition T1A More details
- Transition T2A More details
- Transition T3A More details
- Transition T3B More details
- Transition T3C More details
- Transition T5A More details
- Transition T6A 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
The Reference State is a description of this ecological site just prior to Euro-American settlement but long after the arrival of Native Americans. The description of the Reference State was determined by NRCS Soil Survey Type Site Location information and familiarity with rangeland relict areas where they exist. The least modified plant community would have been dominated by slender wheatgrass (Elymus trachycaulus) with a mixture of mule-ears (Wyethia amplexicaulis) and bluebunch wheatgrass (Pseudoroegneria spicata) and other assorted forbs, along with a scattering of mountain big sagebrush (Artemisia tridentata ssp. vaseyana) (1.1). As the time since the last wildfire lengthened (1.1a), mountain big sagebrush would have increased with a corresponding decrease in the palatable herbaceous component. The primary disturbance factor prior to colonization would have been wildfire (1.2a), which would have reset the vegetation back to an herbaceous-dominated community (1.1). A more complete list of species by lifeform for the Reference State is available in the accompanying tables in the “Plant Community Composition by Weight and Percentage” section of this document.
Submodel
Description
State 2 is a description of the ecological site shortly following Euro-American settlement, which has been influenced by the introduction of several non-native plants and animals, possible extinctions of native species, and a different climate. This state can be regarded as the current potential. Areas of concentrated livestock grazing may have reduced many of the palatable species that were previously abundant. As with State 1, this state is also driven by fire return interval. Mule-ears, slender wheatgrass, and other herbs will be dominant (2.1) just following a fire event (2.2a), but as time since last fire lengthens (2.1a) an increase in mountain big sagebrush will be evident (2.2). A key factor influencing state resiliency on this site is the shrink-swell soils that limit the invasion of woody species. This state will remain stable when livestock grazing, especially during the growing season, is reduced. Alternatively, continued heavy grazing, especially during the growing season will reduce state stability.
Submodel
Description
In the absence of fire, but with continued heavy impacts from livestock grazing, the native grasses will markedly decrease, allowing the shrubs, mainly mountain big sagebrush and unpalatable species like mule-ears, to take over the site. The state will maintain stability with reductions in livestock grazing, especially during the growing season. Alternatively, continued heavy livestock grazing will reduce state stability.
Characteristics and indicators
absence of fire, but with continued heavy impacts from livestock grazing
Submodel
Description
This state would have some scattered mountain big sagebrush but would be dominated by introduced grasses, such as smooth brome (Bromus inermis), orchardgrass (Dactylis glomerata), and intermediate wheatgrass (Thinopyrum intermedium).
Submodel
Description
This is a state dominated by mule-ears, though some mountain big sage and grasses are evident.
Submodel
Mechanism
The simultaneous introduction of exotic species, both plants and animals, possible extinctions of native flora and fauna, and climate change caused State 1 to transition to State 2. Reversal of such historic changes (i.e. a return pathway) back to State 1 is impracticable.
Mechanism
Lack of fire and continued heavy livestock grazing during the growing season of grasses will cause a transition into mountain big sagebrush super-dominance (State 3). Key indicators of the approach to this transition are a loss of perennial grass understory, accelerated soil loss, and an increase in shrubs and unpalatable mule-ears relative to grasses. Sustained heavy grazing over the entire growing season triggers this transition. A restoration pathway is impracticable due to a lack of native perennial grass seed source and partial soil loss.
Mechanism
The key indicator of the approach to this transition is an increase in all size-age form classes of sagebrush, and the trigger is continued growing season-long livestock grazing. A restoration pathway is possible with the use of 2, 4-D™ or 3, 4-5T™, which will reduce sagebrush, mule-ears and other forbs. Deferring livestock use will also allow the recovery of grasses.
Mechanism
A key indicator of the approach to this transition is the build up of fuel, and the trigger is fire. A restoration pathway is possible by reseeding desirable species immediately following fire, and the deferment of grazing until they are established. Another alternative would be proactively spraying 2, 4-D™ or 2, 4-5T™ to reduce mule-ears, and then subsequently reseed.
Mechanism
The key indicator of the approach to this transition is a buildup of fuel, and the trigger is fire. A restoration pathway is possible by first using 2, 4-D™ or 2, 4-5T™ to kill the sagebrush and mule-ears (but also other forbs), and then follow with a deferment of cattle grazing until stand establishment.
Mechanism
Tillage and/or brush removal using herbicides, along with re-seeding and grazing deferment will create a monoculture of the introduced species. Key indicators of the approach to this transition are a loss of palatable species, and the dominance of mule-ears and other unpalatable species. The trigger for this transition is a management decision.
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.